U V W X Y Z - Health
Urinary system
Urticaria (hives)
Uveitis - Equine Recurrent Uveitis
Vaccinations
Vasculitis - Pastern Leucocytoclastic
Veterinary Medicines Directorate
Vibration therapy
Vital signs
Vitiligo
Weaning
Weight (average weights for horse breeds)
Weight loss
Well-being
Windgalls
Windsucking - see crib biting
Worming
Wounds
Urticaria (hives)
Uveitis - Equine Recurrent Uveitis
Vaccinations
Vasculitis - Pastern Leucocytoclastic
Veterinary Medicines Directorate
Vibration therapy
Vital signs
Vitiligo
Weaning
Weight (average weights for horse breeds)
Weight loss
Well-being
Windgalls
Windsucking - see crib biting
Worming
Wounds
Urinary system
Urine - colour
Urine pH
Urinalysis
Urinary tract disorders
Cystitis
Bladder stones or urolithiasis
Incontinence
What can a urine sample tell us? by Mark Grant from Rossdales Equine Practice
Horses usually pass urine in fairly substantial volumes. If a horse appears uncomfortable or straining while passing urine, only passes small quantities or dribbles urine, this could suggest problems and require veterinary investigation. The colour varies from almost colourless to yellow or cream. Creamy colour is due to calcium carbonate crystals and is normal in horses. Crystals can form stones in the bladder and partially or completely block urine flow and damage the urinary tract wall, causing blood to be seen in the urine.
Collect a urine sample for urinalysis from mid-stream into a clean container, and examine quickly or chill.
Cloudiness of urine can also be due to excess protein or cellular material.
Red urine is due to blood (haematuria) e.g. from urolithiasis (crystals or stones), urinary tract infections e.g. cystitis, drug toxicity, neoplasia (cancerous growths) or, rarely, damage to the urethra.
Brown urine can be due to abnormal pigments in the urine such as myoglobin, seen in horses with rhabdomyolysis and atypical myopathy.
Some drugs, foods and bacteria can also change the colour of urine.
Dipsticks can be used to assess urine pH, protein, glucose and bilirubin. Normal urine is alkaline and should not contain protein, glucose or bilirubin.
Specific gravity (SG) measures the concentration of urine - the darker the urine, the higher the SG. Concentrated urine can be caused by decreased water intake or dehydration. Very dilute urine can be caused by excessive water intake e.g. kidney disease or diabetes (although diabetes is rare in horses) (or PPID).
Urine - Colour
The colour of horse urine is highly variable, ranging from almost colourless to orange-yellow (usually yellow), and tends to be a bit cloudy. Darker colours can suggest health issues:
Dark or red urine
When urine contains blood the horse has hematuria. Blood in the urine can be caused by:
Bladder stone
Urinary tract infection
Cancer
Tear in the lining of the urinary tract. Urethral tears occur in stallions and geldings. Urine is normal colour and volume but at the end of urination urethral contractions cause bright red urine to pass, due to blood coming from a tear in the urethra. The condition may resolve without treatment, but may require surgery, particularly if anaemia develops.
Exercise-associated hematuria caused by the abdominal organs pounding the bladder against the pelvis during (intense) exercise - this leads to ulceration of the inner lining of the bladder, and is seen in horses that tend to urinate before exercise and horses that exercise for a long time e.g. endurance horses.
Idiopathic renal hematuria - large clots of blood are often seen in the urine, coming from one or both kidneys, possibly caused by renal adenocarcinoma or abnormal blood vessel anatomy (idiopathic = cause never identified). Male and female horses may develop this condition, and it may be more commonly found in Arabian horses. Treatment may require blood transfusions and medicines to increase blood clotting.
Brown or coffee coloured urine
Brown or coffee coloured urine is often due to myoglobin and the result of muscle damage, e.g. tying up (exertional rhabdomyosis). Myoglobin is an oxygen-containing protein found in muscle cells, and when a muscle is damaged myoglobin is released into the blood and is filtered out by the kidneys and eliminated in the urine, turning the urine brown. Urine containing myoglobin tends to be foamy.
Myoglobin can damage the kidneys, particularly if horses are dehydrated.
Horses that are very dehydrated can have very concentrated urine which can also appear brown.
Causes of Red Urine in Horses Reviewed - Stacey Oke, www.thehorse.com, January 2012
Urine appears Dark Brown or Coffee Colored - Horse Side Vet Guide
Urine pH
Horse urine is typically alkaline, with normal pH in adult horses ranging from around 7.5 to 8.5, and 5.5 to 8.0 in foals (source: Robinson and Sprayberry Current Therapy in Equine Medicine 2009). (The AAEVT's Equine Manual for Veterinary Technicians gives a normal urinary pH range of 7.0 to 9.0 - p 204). The horse's diet affects the urine pH, with horses eating mostly grass or grass hay having a higher pH than horses eating a more cereal-based diet - Wood et al. 1990 found that the pH of urine when horses were grazing was 7.9, and 7.4 when their diet was supplemented with grain. pH decreases with starvation, and urine pH can also be affected by medication, disease and exercise (exercise may cause pH to decrease). Urine pH can be measured with reagent strip colorimetric test strips (dipsticks) but these may only be accurate to within around 0.5 of a pH unit, so a result of 7.5 might indicate that the actual pH is likely to be between 7.0 and 8.0.
Urine pH - Current Therapy in Equine Medicine p751
Goren G, Fritz J, Dillitzer N, Hipp B, Kienzle E.
Fresh and preserved green fodder modify effects of urinary acidifiers on urine pH of horses.
J Anim Physiol Anim Nutr (Berl). 2014 Apr;98(2):239-45. doi: 10.1111/jpn.12071. Epub 2013 Mar 30. PMID: 23551706.
The pH of urine from ponies fed diets based on fresh or preserved green fodder did not decrease below 7.0, even when acidifiers were added to the diet. The mean urine pH of each diet (without acidifiers) was:
Fresh grass 7.58
Alfalfa hay 7.73
Grass cobs 7.63
Grass silage 7.91
Straw 7.87
Extruded straw 7.8
See also Dietary Management to Prevent Horse Bladder Stones - KER July 2014
Wood T, Weckman TJ, Henry PA, Chang SL, Blake JW, Tobin T.
Equine urine pH: normal population distributions and methods of acidification.
Equine Vet J. 1990 Mar;22(2):118-21. doi: 10.1111/j.2042-3306.1990.tb04222.x. PMID: 2318175.
Urinalysis
Urinalysis - Rossdales Laboratories
Urinalysis - Liphook Equine Hospital 2016
Urinary tract disorders
Infections of the urinary system are often caused by bacteria. Bacteria may enter the body e.g. through the urethra, or bacterial infection may be the result of a problem such as an obstruction in the urinary tract, e.g. due to stones. Urinary tract infections are fairly rare in healthy horses.
Urinary Tract Disorders in Horses - Thomas Divers Cornell University 2019
Infection Diseases of the Urinary System in Horses - MSD Manual 2020
Cystitis
Infection Diseases of the Urinary System in Horses - MSD Manual 2020
Bacterial cystitis involves infection and inflammation of the bladder due to bacteria, often the result of an obstruction in the urinary tract.
Clinical signs of cystitis include frequent urination, dribbling urine, urine scalding the hind legs, straining to urinate. There may be blood in the urine.
Diagnosis is made from bacterial analysis of a urine sample.
Treatment includes antibiotics targeted to the bacteria identified, and identifying and treating any underlying reason for the cystitis.
Zakia LS, Gomez DE, Kenney DG, Arroyo LG.
Sabulous cystitis in the horse: 13 cases (2013-2020).
Can Vet J. 2021 Jul;62(7):743-750. PMID: 34219784; PMCID: PMC8218954.
Bladder stones or urolithiasis
Urolithiasis in Horses - MSD Manual 2021
Bladder Stones in Horses - KER September 2016
Incontinence
Urinary Incontinence in the Horse - Vet360
Incontinence - Vetstream
Differential diagnosis of urinary incontinence - Melissa Hines, Equine Neurology
Urinary incontinence: A drippy problem (Proceedings) - Harold Schott - DVM360 April 2010
See also:
Phallectomy
Urine - colour
Urine pH
Urinalysis
Urinary tract disorders
Cystitis
Bladder stones or urolithiasis
Incontinence
What can a urine sample tell us? by Mark Grant from Rossdales Equine Practice
Horses usually pass urine in fairly substantial volumes. If a horse appears uncomfortable or straining while passing urine, only passes small quantities or dribbles urine, this could suggest problems and require veterinary investigation. The colour varies from almost colourless to yellow or cream. Creamy colour is due to calcium carbonate crystals and is normal in horses. Crystals can form stones in the bladder and partially or completely block urine flow and damage the urinary tract wall, causing blood to be seen in the urine.
Collect a urine sample for urinalysis from mid-stream into a clean container, and examine quickly or chill.
Cloudiness of urine can also be due to excess protein or cellular material.
Red urine is due to blood (haematuria) e.g. from urolithiasis (crystals or stones), urinary tract infections e.g. cystitis, drug toxicity, neoplasia (cancerous growths) or, rarely, damage to the urethra.
Brown urine can be due to abnormal pigments in the urine such as myoglobin, seen in horses with rhabdomyolysis and atypical myopathy.
Some drugs, foods and bacteria can also change the colour of urine.
Dipsticks can be used to assess urine pH, protein, glucose and bilirubin. Normal urine is alkaline and should not contain protein, glucose or bilirubin.
Specific gravity (SG) measures the concentration of urine - the darker the urine, the higher the SG. Concentrated urine can be caused by decreased water intake or dehydration. Very dilute urine can be caused by excessive water intake e.g. kidney disease or diabetes (although diabetes is rare in horses) (or PPID).
Urine - Colour
The colour of horse urine is highly variable, ranging from almost colourless to orange-yellow (usually yellow), and tends to be a bit cloudy. Darker colours can suggest health issues:
Dark or red urine
When urine contains blood the horse has hematuria. Blood in the urine can be caused by:
Bladder stone
Urinary tract infection
Cancer
Tear in the lining of the urinary tract. Urethral tears occur in stallions and geldings. Urine is normal colour and volume but at the end of urination urethral contractions cause bright red urine to pass, due to blood coming from a tear in the urethra. The condition may resolve without treatment, but may require surgery, particularly if anaemia develops.
Exercise-associated hematuria caused by the abdominal organs pounding the bladder against the pelvis during (intense) exercise - this leads to ulceration of the inner lining of the bladder, and is seen in horses that tend to urinate before exercise and horses that exercise for a long time e.g. endurance horses.
Idiopathic renal hematuria - large clots of blood are often seen in the urine, coming from one or both kidneys, possibly caused by renal adenocarcinoma or abnormal blood vessel anatomy (idiopathic = cause never identified). Male and female horses may develop this condition, and it may be more commonly found in Arabian horses. Treatment may require blood transfusions and medicines to increase blood clotting.
Brown or coffee coloured urine
Brown or coffee coloured urine is often due to myoglobin and the result of muscle damage, e.g. tying up (exertional rhabdomyosis). Myoglobin is an oxygen-containing protein found in muscle cells, and when a muscle is damaged myoglobin is released into the blood and is filtered out by the kidneys and eliminated in the urine, turning the urine brown. Urine containing myoglobin tends to be foamy.
Myoglobin can damage the kidneys, particularly if horses are dehydrated.
Horses that are very dehydrated can have very concentrated urine which can also appear brown.
Causes of Red Urine in Horses Reviewed - Stacey Oke, www.thehorse.com, January 2012
Urine appears Dark Brown or Coffee Colored - Horse Side Vet Guide
Urine pH
Horse urine is typically alkaline, with normal pH in adult horses ranging from around 7.5 to 8.5, and 5.5 to 8.0 in foals (source: Robinson and Sprayberry Current Therapy in Equine Medicine 2009). (The AAEVT's Equine Manual for Veterinary Technicians gives a normal urinary pH range of 7.0 to 9.0 - p 204). The horse's diet affects the urine pH, with horses eating mostly grass or grass hay having a higher pH than horses eating a more cereal-based diet - Wood et al. 1990 found that the pH of urine when horses were grazing was 7.9, and 7.4 when their diet was supplemented with grain. pH decreases with starvation, and urine pH can also be affected by medication, disease and exercise (exercise may cause pH to decrease). Urine pH can be measured with reagent strip colorimetric test strips (dipsticks) but these may only be accurate to within around 0.5 of a pH unit, so a result of 7.5 might indicate that the actual pH is likely to be between 7.0 and 8.0.
Urine pH - Current Therapy in Equine Medicine p751
Goren G, Fritz J, Dillitzer N, Hipp B, Kienzle E.
Fresh and preserved green fodder modify effects of urinary acidifiers on urine pH of horses.
J Anim Physiol Anim Nutr (Berl). 2014 Apr;98(2):239-45. doi: 10.1111/jpn.12071. Epub 2013 Mar 30. PMID: 23551706.
The pH of urine from ponies fed diets based on fresh or preserved green fodder did not decrease below 7.0, even when acidifiers were added to the diet. The mean urine pH of each diet (without acidifiers) was:
Fresh grass 7.58
Alfalfa hay 7.73
Grass cobs 7.63
Grass silage 7.91
Straw 7.87
Extruded straw 7.8
See also Dietary Management to Prevent Horse Bladder Stones - KER July 2014
Wood T, Weckman TJ, Henry PA, Chang SL, Blake JW, Tobin T.
Equine urine pH: normal population distributions and methods of acidification.
Equine Vet J. 1990 Mar;22(2):118-21. doi: 10.1111/j.2042-3306.1990.tb04222.x. PMID: 2318175.
Urinalysis
Urinalysis - Rossdales Laboratories
Urinalysis - Liphook Equine Hospital 2016
Urinary tract disorders
Infections of the urinary system are often caused by bacteria. Bacteria may enter the body e.g. through the urethra, or bacterial infection may be the result of a problem such as an obstruction in the urinary tract, e.g. due to stones. Urinary tract infections are fairly rare in healthy horses.
Urinary Tract Disorders in Horses - Thomas Divers Cornell University 2019
Infection Diseases of the Urinary System in Horses - MSD Manual 2020
Cystitis
Infection Diseases of the Urinary System in Horses - MSD Manual 2020
Bacterial cystitis involves infection and inflammation of the bladder due to bacteria, often the result of an obstruction in the urinary tract.
Clinical signs of cystitis include frequent urination, dribbling urine, urine scalding the hind legs, straining to urinate. There may be blood in the urine.
Diagnosis is made from bacterial analysis of a urine sample.
Treatment includes antibiotics targeted to the bacteria identified, and identifying and treating any underlying reason for the cystitis.
Zakia LS, Gomez DE, Kenney DG, Arroyo LG.
Sabulous cystitis in the horse: 13 cases (2013-2020).
Can Vet J. 2021 Jul;62(7):743-750. PMID: 34219784; PMCID: PMC8218954.
Bladder stones or urolithiasis
Urolithiasis in Horses - MSD Manual 2021
Bladder Stones in Horses - KER September 2016
Incontinence
Urinary Incontinence in the Horse - Vet360
Incontinence - Vetstream
Differential diagnosis of urinary incontinence - Melissa Hines, Equine Neurology
Urinary incontinence: A drippy problem (Proceedings) - Harold Schott - DVM360 April 2010
See also:
Phallectomy
Urticaria (hives)
Littlewood, Janet
Diagnostic investigation of urticaria
BEVA Congress September 2022 Handbook of presentations p 202 (IVIS)
Littlewood, Janet
Diagnostic investigation of urticaria
BEVA Congress September 2022 Handbook of presentations p 202 (IVIS)
Uveitis - Equine Recurrent Uveitis (ERU)
Uveitis is the inflammation of the uveal tract (the iris, ciliary body and choroid) of the eye, and can be either primary, or secondary to an injury or abnormality. Uveitis can be acute, chronic (i.e. not resolved) or recurrent.
3 clinical forms of Equine Recurrent Uveitis have been classified: classic, insidious, posterior.
Classic ERU has episodes of active intraocular inflammation, with each inflammatory episode often showing increased severity.
Insidious ERU is the most common form seen in Appaloosa horses and has a persistent low-grade inflammation with few external signs but a cumulative destructive effect.
Posterior uveitis is the most common form seen in Warmbloods and horses in continental Europe, and affects mainly the vitreous, choroid and retina.
ERU generally develops after an initial episode of primary uveitis, but not every case of primary uveitis will recurr.
Research has shown an association between leptospirosis and uveitis.
Malalana F, Ireland JL, Pinchbeck GL, McGowan CM.
Risk factors for a first episode of primary uveitis in the UK and proportion of cases that experience recurrence following this first episode.
Equine Vet J. 2023 Jan;55(1):42-47. doi: 10.1111/evj.13576. Epub 2022 Apr 4. PMID: 35305037.
Over 4 years, 23 horses were reported or admitted to Philip Leverhulme Equine Hospital (north-west England) diagnosed with a first episode of primary spontaneous uveitis. In these horses, uveitis was associated with spending time on flooded fields or being kept close to pigs, but these results should be treated with caution. 22% of cases were not controlled with medical therapy and required surgical therapy, and 18% of cases recurred.
Fernando Malalana Martinez
Epidemiology, risk factors and features associated with equine primary uveitis in North-West England and Queensland, Australia
PhD thesis University of Liverpool January 2021
Sandmeyer LS, Kingsley NB, Walder C, Archer S, Leis ML, Bellone RR, Bauer BS.
Risk factors for equine recurrent uveitis in a population of Appaloosa horses in western Canada.
Vet Ophthalmol. 2020 May;23(3):515-525. doi: 10.1111/vop.12749. Epub 2020 Feb 22. PMID: 32086865.
14% (20) of 145 Appaloosa horses in Canada had ERU - 10 of the affected horses were directly related. Age, coat pattern, and genetics are major risk factors for the diagnosis and classification of ERU in the Appaloosa.
See also Risk Factors for Equine Recurrent Uveitis in Appaloosas - Nancy Loving June 2020 EquiManagement
Equine Recurrent Uveitis: The Latest - Alexandra Beckstett, www.thehorse.com, Nov 2018
McMullen RJ, Fischer BM
Medical and Surgical Management of Equine Recurrent Uveitis
Veterinary Clinics Equine Practise: published online Oct 2017
Equine Recurrent Uveitis: Classification, Etiology, and Pathogenesis - Amanda Curling VetLearn June 2011
Equine Recurrent Uveitis: Treatment - Amanda Curling VetLearn June 2011
Compend Contin Educ Vet. 2011 Jun;33(6):E2 (PubMed).
Equine recurrent uveitis: classification, etiology, and pathogenesis.
Curling A.
"Equine recurrent uveitis is a cyclical disease that affects the eye and often leads to high management costs and unfavorable results, such as blindness. Research has improved understanding of the roles of various etiologies, especially leptospirosis, in initiating and perpetuating the pathogenesis of equine recurrent uveitis. Research has also led to the discovery that specific breeds and horses with specific coat color patterns may be predisposed to developing recurrent uveitis."
Vet Microbiol. 2013 Nov 29;167(1-2):61-6. doi: 10.1016/j.vetmic.2013.04.012. Epub 2013 Apr 16 (PubMed).
Leptospirosis in horses.
Verma A, Stevenson B, Adler B.
"Leptospirosis in horses has been considered a relatively uncommon infection. However, recent data suggest that the infection is widespread, with the incidence and infecting serovars varying considerably in different geographical regions. The majority of infections remain asymptomatic. Clinical signs in equine leptospirosis resemble those seen in other animal species. However, leptospirosis as a cause of acute respiratory distress is becoming more frequently recognised. A particular feature of equine leptospirosis is post infection recurrent uveitis (moon blindness or periodic ophthalmia), which appears to be mediated by autoimmune mechanisms involving cross reactivity between ocular tissues and leptospiral membrane proteins. There are no leptospiral vaccines licensed for use in horses, with no prospect for any becoming available in the foreseeable future. Accordingly, prevention of equine leptospirosis must rely on good hygiene practices, minimisation of rodent contact, and vaccination of other species of production and companion animals."
Uveitis is the inflammation of the uveal tract (the iris, ciliary body and choroid) of the eye, and can be either primary, or secondary to an injury or abnormality. Uveitis can be acute, chronic (i.e. not resolved) or recurrent.
3 clinical forms of Equine Recurrent Uveitis have been classified: classic, insidious, posterior.
Classic ERU has episodes of active intraocular inflammation, with each inflammatory episode often showing increased severity.
Insidious ERU is the most common form seen in Appaloosa horses and has a persistent low-grade inflammation with few external signs but a cumulative destructive effect.
Posterior uveitis is the most common form seen in Warmbloods and horses in continental Europe, and affects mainly the vitreous, choroid and retina.
ERU generally develops after an initial episode of primary uveitis, but not every case of primary uveitis will recurr.
Research has shown an association between leptospirosis and uveitis.
Malalana F, Ireland JL, Pinchbeck GL, McGowan CM.
Risk factors for a first episode of primary uveitis in the UK and proportion of cases that experience recurrence following this first episode.
Equine Vet J. 2023 Jan;55(1):42-47. doi: 10.1111/evj.13576. Epub 2022 Apr 4. PMID: 35305037.
Over 4 years, 23 horses were reported or admitted to Philip Leverhulme Equine Hospital (north-west England) diagnosed with a first episode of primary spontaneous uveitis. In these horses, uveitis was associated with spending time on flooded fields or being kept close to pigs, but these results should be treated with caution. 22% of cases were not controlled with medical therapy and required surgical therapy, and 18% of cases recurred.
Fernando Malalana Martinez
Epidemiology, risk factors and features associated with equine primary uveitis in North-West England and Queensland, Australia
PhD thesis University of Liverpool January 2021
Sandmeyer LS, Kingsley NB, Walder C, Archer S, Leis ML, Bellone RR, Bauer BS.
Risk factors for equine recurrent uveitis in a population of Appaloosa horses in western Canada.
Vet Ophthalmol. 2020 May;23(3):515-525. doi: 10.1111/vop.12749. Epub 2020 Feb 22. PMID: 32086865.
14% (20) of 145 Appaloosa horses in Canada had ERU - 10 of the affected horses were directly related. Age, coat pattern, and genetics are major risk factors for the diagnosis and classification of ERU in the Appaloosa.
See also Risk Factors for Equine Recurrent Uveitis in Appaloosas - Nancy Loving June 2020 EquiManagement
Equine Recurrent Uveitis: The Latest - Alexandra Beckstett, www.thehorse.com, Nov 2018
McMullen RJ, Fischer BM
Medical and Surgical Management of Equine Recurrent Uveitis
Veterinary Clinics Equine Practise: published online Oct 2017
Equine Recurrent Uveitis: Classification, Etiology, and Pathogenesis - Amanda Curling VetLearn June 2011
Equine Recurrent Uveitis: Treatment - Amanda Curling VetLearn June 2011
Compend Contin Educ Vet. 2011 Jun;33(6):E2 (PubMed).
Equine recurrent uveitis: classification, etiology, and pathogenesis.
Curling A.
"Equine recurrent uveitis is a cyclical disease that affects the eye and often leads to high management costs and unfavorable results, such as blindness. Research has improved understanding of the roles of various etiologies, especially leptospirosis, in initiating and perpetuating the pathogenesis of equine recurrent uveitis. Research has also led to the discovery that specific breeds and horses with specific coat color patterns may be predisposed to developing recurrent uveitis."
Vet Microbiol. 2013 Nov 29;167(1-2):61-6. doi: 10.1016/j.vetmic.2013.04.012. Epub 2013 Apr 16 (PubMed).
Leptospirosis in horses.
Verma A, Stevenson B, Adler B.
"Leptospirosis in horses has been considered a relatively uncommon infection. However, recent data suggest that the infection is widespread, with the incidence and infecting serovars varying considerably in different geographical regions. The majority of infections remain asymptomatic. Clinical signs in equine leptospirosis resemble those seen in other animal species. However, leptospirosis as a cause of acute respiratory distress is becoming more frequently recognised. A particular feature of equine leptospirosis is post infection recurrent uveitis (moon blindness or periodic ophthalmia), which appears to be mediated by autoimmune mechanisms involving cross reactivity between ocular tissues and leptospiral membrane proteins. There are no leptospiral vaccines licensed for use in horses, with no prospect for any becoming available in the foreseeable future. Accordingly, prevention of equine leptospirosis must rely on good hygiene practices, minimisation of rodent contact, and vaccination of other species of production and companion animals."
Vaccinations
Did you know:
- Only healthy animals should be vaccinated - your vet should carry out basic health checks (this will often include checking temperature, heart rate, listening to heart and lungs) and ask about any recent history of signs of illness before giving a vaccination.
- Adverse reactions may be seen following vaccinations AND SHOULD ALWAYS BE REPORTED to your vet and to the marketing authorisation holder (in the UK this is the Veterinary Medicines Directorate - see online form below). Adverse reactions may include swelling, heat, pain and muscle stiffness around the injection site, increased temperature, injection site abscess, apathy, decreased appetite, hypersensitivity reaction/anaphylaxis.
In the UK, use this online form to report an adverse reaction to a vaccine or any medicine:
Animal Adverse Reaction Reporting
Among other information, you will be asked for:
Product Name, Batch No and Expiry Date - these are all found on the sticker from the vaccine bottle in your vaccination record card/passport.
Administration Start Date (date the vaccine was given), Administered By (usually veterinary surgeon), Administration Route (intramuscular use for a flu/tetanus vaccine).
Details about the horse - breed, age, sex, weight.
When the reaction started, how long it lasted or if still ongoing, description of the reaction, whether the horse received treatment for the reaction.
Your contact details in case more information is required - an email and/or postal address are required to submit the report and receive acknowledgement. If you do not give an email address, make sure you print a copy of the report from the submission screen (and give a copy to your vet/the owner). You can give your vet's details (optional).
You get the chance to check the information you have given before you click on Submit Report - print the summary for your records and to give to your vet/owner if you have not given an email address.
- Different makes of vaccination have different intervals for revaccination (boosters)? For example:
Equip FT: duration of immunity (after primary vaccination course) for influenza is 15 months and for tetanus is 36 months.
Dose: 2 ml given: first dose V#1 Equip FT, V#2 6 weeks later Equip FT, V#3 5 months later Equip F, V#4 12-15 months later Equip F, V#5 12-15 months later Equip FT.
Active substances: inactivated strains of A/equine/Newmarket/77 H7N7, A/equine/Borlange/91 H3N8, A/equine/Kentucky/98 H3N8, immunopurified Tetanus Toxoid.
Adjuvants/excipients: Quillaic Acid derivative (Quil A - this is a saponin), aluminium phosphate, phosphatidyl choline, cholesterol, ammonium acetate, phosphate buffered saline.
See Veterinary Medicines Directorate Summary of Product Characteristics for Equip FT
ProteqFlu-Te: duration of immunity (after primary vaccination course) for influenza is 12 months and for tetanus is 24 months.
Dose: 1 ml given: first dose V#1 ProteqFlu-Te, V#2 4-6 weeks later ProteqFlu-Te, V#3 5 months later ProteqFlu-Te, V#4 12 months later ProteqFlu, V#5 12 months later ProteqFlu-Te.
Active substances: A/equine/Ohio/03 H3H8, A/equine/Richmond/1/07 H3N8, Clostridium tetani toxoid.
Adjuvants/excipients: carbomer, sodium chloride, disodium hydrogen orthophosphate, monopotassium phosphate anhydrous, water.
See Veterinary Medicines Directorate Summary of Product Characteristics for ProteqFlu-Te
Equilis Prequenza Te: duration of immunity for influenza is 12 months and for tetanus is maximum 24 months (17 months for vaccine #4).
Dose: 1 ml given: first dose V#1 Prequenza TE, V#2 4 weeks later Prequenza TE, V#3 5 months later Prequenza, V#4 12 months later Prequenza TE, V#5 12 months later Prequenza, V#6 12 months later Prequenza Te.
Active substances: A/equine-2/South Africa/4/03, A/equine-2/Newmarket/2/93, Tetanus toxoid.
Adjuvants/excipients: purified saponin, cholesterol, phosphatidylcholine, phosphate buffer, traces of thiomersal, traces of formaldehyde.
See Veterinary Medicines Directorate Summary of Product Characteristics for Equilis Prequenza TE
NOAH - Equine Vaccination
Vaccine Reactions - Tom Schell www.thehorse.com Aug 2014
Vaccines - www.thelaminitissite.org
J Comp Pathol. 2010 Jan;142 Suppl 1:S85-90
The effect of age on the immune response of horses to vaccination
Muirhead TL, McClure JT, Wichtel JJ, Stryhn H, Markham RJ, McFarlane D, Lunn DP
Few studies have investigated immunosenescence in the horse, but it is accepted that the primary and secondary (anamnestic) immune responses may differ between aged and younger horses. The aim of the present study was to determine whether aged horses have a protective immune response post-vaccination. Thirty-four aged healthy horses (> or =20 years) and 29 younger adult horses (4-12 years) of various breeds were vaccinated with commercially produced killed rabies and influenza vaccines. Rabies serum neutralizing antibody titres and equine influenza virus specific antibody subclasses (immunoglobulin IgGa and IgGb) and single radial haemolysis titres were determined. Healthy aged horses mounted a primary immune response to rabies vaccine that was similar to that of younger adult horses. However, aged horses had a significantly reduced anamnestic response to influenza vaccination in comparison with the younger adult horses, even though the pre-vaccination antibody titres of aged horses were higher. Rabies antibody titres in both groups declined significantly by 6 months post-vaccination. Serum concentrations of selenium (Se) and vitamin E were measured to test for potential confounding effects. Significant numbers of horses had suboptimal serum Se concentrations, but Se status had no significant impact on antibody production after vaccination.
Did you know:
- Only healthy animals should be vaccinated - your vet should carry out basic health checks (this will often include checking temperature, heart rate, listening to heart and lungs) and ask about any recent history of signs of illness before giving a vaccination.
- Adverse reactions may be seen following vaccinations AND SHOULD ALWAYS BE REPORTED to your vet and to the marketing authorisation holder (in the UK this is the Veterinary Medicines Directorate - see online form below). Adverse reactions may include swelling, heat, pain and muscle stiffness around the injection site, increased temperature, injection site abscess, apathy, decreased appetite, hypersensitivity reaction/anaphylaxis.
In the UK, use this online form to report an adverse reaction to a vaccine or any medicine:
Animal Adverse Reaction Reporting
Among other information, you will be asked for:
Product Name, Batch No and Expiry Date - these are all found on the sticker from the vaccine bottle in your vaccination record card/passport.
Administration Start Date (date the vaccine was given), Administered By (usually veterinary surgeon), Administration Route (intramuscular use for a flu/tetanus vaccine).
Details about the horse - breed, age, sex, weight.
When the reaction started, how long it lasted or if still ongoing, description of the reaction, whether the horse received treatment for the reaction.
Your contact details in case more information is required - an email and/or postal address are required to submit the report and receive acknowledgement. If you do not give an email address, make sure you print a copy of the report from the submission screen (and give a copy to your vet/the owner). You can give your vet's details (optional).
You get the chance to check the information you have given before you click on Submit Report - print the summary for your records and to give to your vet/owner if you have not given an email address.
- Different makes of vaccination have different intervals for revaccination (boosters)? For example:
Equip FT: duration of immunity (after primary vaccination course) for influenza is 15 months and for tetanus is 36 months.
Dose: 2 ml given: first dose V#1 Equip FT, V#2 6 weeks later Equip FT, V#3 5 months later Equip F, V#4 12-15 months later Equip F, V#5 12-15 months later Equip FT.
Active substances: inactivated strains of A/equine/Newmarket/77 H7N7, A/equine/Borlange/91 H3N8, A/equine/Kentucky/98 H3N8, immunopurified Tetanus Toxoid.
Adjuvants/excipients: Quillaic Acid derivative (Quil A - this is a saponin), aluminium phosphate, phosphatidyl choline, cholesterol, ammonium acetate, phosphate buffered saline.
See Veterinary Medicines Directorate Summary of Product Characteristics for Equip FT
ProteqFlu-Te: duration of immunity (after primary vaccination course) for influenza is 12 months and for tetanus is 24 months.
Dose: 1 ml given: first dose V#1 ProteqFlu-Te, V#2 4-6 weeks later ProteqFlu-Te, V#3 5 months later ProteqFlu-Te, V#4 12 months later ProteqFlu, V#5 12 months later ProteqFlu-Te.
Active substances: A/equine/Ohio/03 H3H8, A/equine/Richmond/1/07 H3N8, Clostridium tetani toxoid.
Adjuvants/excipients: carbomer, sodium chloride, disodium hydrogen orthophosphate, monopotassium phosphate anhydrous, water.
See Veterinary Medicines Directorate Summary of Product Characteristics for ProteqFlu-Te
Equilis Prequenza Te: duration of immunity for influenza is 12 months and for tetanus is maximum 24 months (17 months for vaccine #4).
Dose: 1 ml given: first dose V#1 Prequenza TE, V#2 4 weeks later Prequenza TE, V#3 5 months later Prequenza, V#4 12 months later Prequenza TE, V#5 12 months later Prequenza, V#6 12 months later Prequenza Te.
Active substances: A/equine-2/South Africa/4/03, A/equine-2/Newmarket/2/93, Tetanus toxoid.
Adjuvants/excipients: purified saponin, cholesterol, phosphatidylcholine, phosphate buffer, traces of thiomersal, traces of formaldehyde.
See Veterinary Medicines Directorate Summary of Product Characteristics for Equilis Prequenza TE
NOAH - Equine Vaccination
Vaccine Reactions - Tom Schell www.thehorse.com Aug 2014
Vaccines - www.thelaminitissite.org
J Comp Pathol. 2010 Jan;142 Suppl 1:S85-90
The effect of age on the immune response of horses to vaccination
Muirhead TL, McClure JT, Wichtel JJ, Stryhn H, Markham RJ, McFarlane D, Lunn DP
Few studies have investigated immunosenescence in the horse, but it is accepted that the primary and secondary (anamnestic) immune responses may differ between aged and younger horses. The aim of the present study was to determine whether aged horses have a protective immune response post-vaccination. Thirty-four aged healthy horses (> or =20 years) and 29 younger adult horses (4-12 years) of various breeds were vaccinated with commercially produced killed rabies and influenza vaccines. Rabies serum neutralizing antibody titres and equine influenza virus specific antibody subclasses (immunoglobulin IgGa and IgGb) and single radial haemolysis titres were determined. Healthy aged horses mounted a primary immune response to rabies vaccine that was similar to that of younger adult horses. However, aged horses had a significantly reduced anamnestic response to influenza vaccination in comparison with the younger adult horses, even though the pre-vaccination antibody titres of aged horses were higher. Rabies antibody titres in both groups declined significantly by 6 months post-vaccination. Serum concentrations of selenium (Se) and vitamin E were measured to test for potential confounding effects. Significant numbers of horses had suboptimal serum Se concentrations, but Se status had no significant impact on antibody production after vaccination.
Vasculitis - Pastern Leucocytoclastic
Lisa Akucewich
EQUINE DERMATOLOGY I
Proceeding of the NAVC North American Veterinary Conference Jan. 8-12, 2005
Lisa Akucewich
EQUINE DERMATOLOGY I
Proceeding of the NAVC North American Veterinary Conference Jan. 8-12, 2005
Veterinary Medicines Directorate
To help prevent the sale or use of products that are not safe or do not do what they claim, any product or supplement that claims to treat or prevent disease must be authorised and given a Marketing Authorisation (MA) number by the Veterinary Medicines Directorate (VMD).
"Animal medicines which are advertised for the treatment or prevention of disease, or which have that function, must be authorised before they can be legally sold or used in the UK. The marketing, importation, sale, supply, administration and possession of an animal medicine not in line with the regulations is illegal."
Legal controls on veterinary medicines
Report illegal animal medicines
Veterinary Medicines Guidance Note No. 1 - Controls of Veterinary Medicines
To help prevent the sale or use of products that are not safe or do not do what they claim, any product or supplement that claims to treat or prevent disease must be authorised and given a Marketing Authorisation (MA) number by the Veterinary Medicines Directorate (VMD).
"Animal medicines which are advertised for the treatment or prevention of disease, or which have that function, must be authorised before they can be legally sold or used in the UK. The marketing, importation, sale, supply, administration and possession of an animal medicine not in line with the regulations is illegal."
Legal controls on veterinary medicines
Report illegal animal medicines
Veterinary Medicines Guidance Note No. 1 - Controls of Veterinary Medicines
Vibration Therapy
Adair, Steve
What is the science behind vibration therapy?
BEVA Congress 2022 Handbook of Presentations 246 (IVIS)
"In summary, the majority of the studies have been unable to document any positive effect of whole body vibration on the horse."
Adair, Steve
What is the science behind vibration therapy?
BEVA Congress 2022 Handbook of Presentations 246 (IVIS)
"In summary, the majority of the studies have been unable to document any positive effect of whole body vibration on the horse."
Vital signs
Also known as TPR (temperature, pulse, respiration rate).
How to take a horse's pulse - World Horse Welfare - shows how to check the mandibular (face) and digital (lower leg) pulses.
How to check your horse's vital signs - Genesee Valley Equine Clinic
Normal Horse Vital Signs and Health Indicators - www.thehorse.com Sep 2011
Taking Vital Signs - Christina Cable, www.thehorse.com Dec 2013
Also known as TPR (temperature, pulse, respiration rate).
How to take a horse's pulse - World Horse Welfare - shows how to check the mandibular (face) and digital (lower leg) pulses.
How to check your horse's vital signs - Genesee Valley Equine Clinic
Normal Horse Vital Signs and Health Indicators - www.thehorse.com Sep 2011
Taking Vital Signs - Christina Cable, www.thehorse.com Dec 2013
Vitiligo
See also Leukoderma.
According to the MSC Veterinary Manual, Vitiligo is hereditary but is not usually seen until early adulthood, and particularly affects Arabian horses. Pale/white areas of skin/hair develop, particularly on the muzzle and around the eyes. Colour may return then fade again, and rarely returns to normal. There are no health problems associated with vitiligo, and no treatment available.
Vitiligo - Simon Constable's Equine Vets
Vitiligo (Arabian Fading Syndrome) - Equine Clinical Medicine, Surgery and Reproduction - Scott Weese, Graham Munroe 2010
See also Leukoderma.
According to the MSC Veterinary Manual, Vitiligo is hereditary but is not usually seen until early adulthood, and particularly affects Arabian horses. Pale/white areas of skin/hair develop, particularly on the muzzle and around the eyes. Colour may return then fade again, and rarely returns to normal. There are no health problems associated with vitiligo, and no treatment available.
Vitiligo - Simon Constable's Equine Vets
Vitiligo (Arabian Fading Syndrome) - Equine Clinical Medicine, Surgery and Reproduction - Scott Weese, Graham Munroe 2010
Weaning
Lansade L, Foury A, Reigner F, Vidament M, Guettier E, Bouvet G, Soulet D, Parias C, Ruet A, Mach N, Lévy F, Moisan MP
Progressive habituation to separation alleviates the negative effects of weaning in the mother and foal
Psychoneuroendocrinology published online 2018 Jul 5;97:59-68. doi: 10.1016/j.psyneuen.2018.07.005
"In conclusion, this study shows that progressive habituation to separation alleviates the negative effect of definitive weaning on both the mother and her young compared to sudden separation."
See also Science Supports Slow, Steady Weaning of Foals - Kentucky Equine Research August 2018
Ferlazzo A, Cravana C, Fazio E, Medica P
The contribution of total and free iodothyronines to welfare maintenance and management stress coping in Ruminants and Equines: Physiological ranges and reference values
Res Vet Sci. 2018 Jun;118:134-143. doi: 10.1016/j.rvsc.2018.01.025. Published online 2018 Feb 2
"Weaning effects were shown for T3 and fT4 concentrations, indicating that weaning represents a severe stress and the presence of conspecific does not reduce psychological stress in this phase."
Lansade L, Foury A, Reigner F, Vidament M, Guettier E, Bouvet G, Soulet D, Parias C, Ruet A, Mach N, Lévy F, Moisan MP
Progressive habituation to separation alleviates the negative effects of weaning in the mother and foal
Psychoneuroendocrinology published online 2018 Jul 5;97:59-68. doi: 10.1016/j.psyneuen.2018.07.005
"In conclusion, this study shows that progressive habituation to separation alleviates the negative effect of definitive weaning on both the mother and her young compared to sudden separation."
See also Science Supports Slow, Steady Weaning of Foals - Kentucky Equine Research August 2018
Ferlazzo A, Cravana C, Fazio E, Medica P
The contribution of total and free iodothyronines to welfare maintenance and management stress coping in Ruminants and Equines: Physiological ranges and reference values
Res Vet Sci. 2018 Jun;118:134-143. doi: 10.1016/j.rvsc.2018.01.025. Published online 2018 Feb 2
"Weaning effects were shown for T3 and fT4 concentrations, indicating that weaning represents a severe stress and the presence of conspecific does not reduce psychological stress in this phase."
Weight (average weights for horse breeds)
Average weight tables for horse breeds:
Horse Weight: 10 Steps to Maximise Control Now - ForagePlus July 2023
Horse Height and Weight: A Guide - Horse & Country TV 2023
Average weight tables for horse breeds:
Horse Weight: 10 Steps to Maximise Control Now - ForagePlus July 2023
Horse Height and Weight: A Guide - Horse & Country TV 2023
Weight Loss (unwanted)
Reasons why a horse might lose weight/be underweight:
insufficient energy intake - the horse simply needs the diet to provide more energy, by increasing the amount fed and/or increasing the digestible energy (DE) content of the feeds.
internal parasite burdens (current and/or previous) - worms may take nutrients from the digestive tract, and damage the intestine walls, reducing the horse's absorption of nutrients, and leading to protein deficiency. Targeted worming should be carried out as advised by a vet and based on fecal egg counts and saliva/blood tests for tapeworm. Horses with a history of high parasite burdens may require higher levels of protein in the diet.
tooth problems - sharp teeth, molar loss, misalignment of teeth, loose teeth (in older horses and milk teeth in younger horses), mouth/tooth infections and other tooth/mouth abnormalities can cause weight loss due to reduced feed intake or reduced grinding and breakdown of feed. Adult horses should have their teeth checked, and rasped if necessary, annually, and young and old horses bi-annually, by a qualified equine dentist or vet who specializes in dentistry. Horses with dentition problems often benefit from feeds that can be soaked to a porridge-like consistency, such as sugar beet pulp, alfalfa pellets, hay pellets, horse & pony cubes, soya mashes, bran, so that little or no chewing is required, and using warm water may make the feed more appetizing.
Investigating weight loss - Liphook Equine Hospital
Investigating weight loss - Liphook Equine Hospital 2016
Wambacq W, De Clercq D, Lefère L, Hesta M
Nutritional management of small intestinal malabsorption syndrome in nine horses
Proceedings of the 19th congress of the ESVCN 2015
Reasons why a horse might lose weight/be underweight:
insufficient energy intake - the horse simply needs the diet to provide more energy, by increasing the amount fed and/or increasing the digestible energy (DE) content of the feeds.
internal parasite burdens (current and/or previous) - worms may take nutrients from the digestive tract, and damage the intestine walls, reducing the horse's absorption of nutrients, and leading to protein deficiency. Targeted worming should be carried out as advised by a vet and based on fecal egg counts and saliva/blood tests for tapeworm. Horses with a history of high parasite burdens may require higher levels of protein in the diet.
tooth problems - sharp teeth, molar loss, misalignment of teeth, loose teeth (in older horses and milk teeth in younger horses), mouth/tooth infections and other tooth/mouth abnormalities can cause weight loss due to reduced feed intake or reduced grinding and breakdown of feed. Adult horses should have their teeth checked, and rasped if necessary, annually, and young and old horses bi-annually, by a qualified equine dentist or vet who specializes in dentistry. Horses with dentition problems often benefit from feeds that can be soaked to a porridge-like consistency, such as sugar beet pulp, alfalfa pellets, hay pellets, horse & pony cubes, soya mashes, bran, so that little or no chewing is required, and using warm water may make the feed more appetizing.
Investigating weight loss - Liphook Equine Hospital
Investigating weight loss - Liphook Equine Hospital 2016
Wambacq W, De Clercq D, Lefère L, Hesta M
Nutritional management of small intestinal malabsorption syndrome in nine horses
Proceedings of the 19th congress of the ESVCN 2015
Wellbeing
A horse's wellbeing is based on its physical, emotional and physiological states - a horse should be healthy and in good condition both physically and mentally.
Five Freedoms for Horse Health and Welfare - Keeping Britain's Horses Healthy
The Animal Welfare Act gives 5 freedoms that all animals are entitled to; for horses this might mean:
Freedom from hunger and thirst - by providing sufficient clean water and the majority of their diet as forage, ideally with free access to allow foraging for at least 16 hours/day,
Freedom from discomfort - by ensuring plenty of turnout, shelter from bad weather, comfortable resting areas, well fitting equipment, and asking horses only to do what they are capable of and enjoy,
Freedom from pain, injury and disease - by taking reasonable steps to prevent illness/injury (including worming, vaccination and a safe environment to prevent injury) and ensuring prompt veterinary care/treatment for ill/injured animals,
freedom from fear and distress - by ensuring their conditions meet their social and mental needs, and their treatment is based on trust and avoids suffering,
Freedom to express natural behaviour - by providing sufficient space/turnout, the company of other horses and environmental enrichment.
Quality of life - British Horse Society November 2022
Krueger K, Esch L, Farmer K, Marr I.
Basic Needs in Horses?-A Literature Review.
Animals (Basel). 2021 Jun 16;11(6):1798. doi: 10.3390/ani11061798. PMID: 34208615; PMCID: PMC8235049.
A review of published literature suggested that restricting social contact, restricting social companionship, restricting free movement and restricting access to roughage/forage causes suffering to horses.
A horse's wellbeing is based on its physical, emotional and physiological states - a horse should be healthy and in good condition both physically and mentally.
Five Freedoms for Horse Health and Welfare - Keeping Britain's Horses Healthy
The Animal Welfare Act gives 5 freedoms that all animals are entitled to; for horses this might mean:
Freedom from hunger and thirst - by providing sufficient clean water and the majority of their diet as forage, ideally with free access to allow foraging for at least 16 hours/day,
Freedom from discomfort - by ensuring plenty of turnout, shelter from bad weather, comfortable resting areas, well fitting equipment, and asking horses only to do what they are capable of and enjoy,
Freedom from pain, injury and disease - by taking reasonable steps to prevent illness/injury (including worming, vaccination and a safe environment to prevent injury) and ensuring prompt veterinary care/treatment for ill/injured animals,
freedom from fear and distress - by ensuring their conditions meet their social and mental needs, and their treatment is based on trust and avoids suffering,
Freedom to express natural behaviour - by providing sufficient space/turnout, the company of other horses and environmental enrichment.
Quality of life - British Horse Society November 2022
Krueger K, Esch L, Farmer K, Marr I.
Basic Needs in Horses?-A Literature Review.
Animals (Basel). 2021 Jun 16;11(6):1798. doi: 10.3390/ani11061798. PMID: 34208615; PMCID: PMC8235049.
A review of published literature suggested that restricting social contact, restricting social companionship, restricting free movement and restricting access to roughage/forage causes suffering to horses.
Webinar: How to support equine mental wellbeing posted on YouTube by World Horse Welfare on 25 August 2021. Dr Andrew McLean reviews equine management and training practices and suggests how we can interact with our horses to optimise their mental wellbeing.
Windgalls/windpuffs
Windpuffs: Resolving a Common Swelling in Horses - Jean-Yin Tan www.thehorse.com Mar 2018
Windpuffs: Resolving a Common Swelling in Horses - Jean-Yin Tan www.thehorse.com Mar 2018
Worms and Worming
The main worms that infect horses are:
Tapeworm - Anoplocephala perfoliata - considered a significant threat in adult horses (causes ileal colic).
Small redworm - Cyathostomins or small strongyles - considered a significant threat in adult horses. Resistance to worming chemicals is a problem. All grazing horses are likely to be infected, but disease is only caused when numbers reach high levels.
A new blood test for small redworm, including encysted, was launched in the UK in September 2019.
Large redworm or blood worm - Strongyles vulgaris - no longer considered a significant threat in adult horses.
Roundworm - Parascaris equorum - also called Ascarids - considered a significant threat in horses under 3 years old. Resistance is a problem.
Rendle D, Hughes K, Bowen M, Bull K, Cameron I, Furtado T, Peachey L, Sharpe L, Hodgkinson J.
BEVA primary care clinical guidelines: Equine parasite control.
Equine Vet J. 2024 Jan 2. doi: 10.1111/evj.14036. Epub ahead of print. PMID: 38169127.
Testing-Led Deworming - British Horse Society 2023
Equine de-worming: a consensus on current best practise - UK-Vet Equine 2019
Westgate Laboratories
NCVP parasite image database
The main worms that infect horses are:
Tapeworm - Anoplocephala perfoliata - considered a significant threat in adult horses (causes ileal colic).
Small redworm - Cyathostomins or small strongyles - considered a significant threat in adult horses. Resistance to worming chemicals is a problem. All grazing horses are likely to be infected, but disease is only caused when numbers reach high levels.
A new blood test for small redworm, including encysted, was launched in the UK in September 2019.
Large redworm or blood worm - Strongyles vulgaris - no longer considered a significant threat in adult horses.
Roundworm - Parascaris equorum - also called Ascarids - considered a significant threat in horses under 3 years old. Resistance is a problem.
Rendle D, Hughes K, Bowen M, Bull K, Cameron I, Furtado T, Peachey L, Sharpe L, Hodgkinson J.
BEVA primary care clinical guidelines: Equine parasite control.
Equine Vet J. 2024 Jan 2. doi: 10.1111/evj.14036. Epub ahead of print. PMID: 38169127.
Testing-Led Deworming - British Horse Society 2023
Equine de-worming: a consensus on current best practise - UK-Vet Equine 2019
Westgate Laboratories
NCVP parasite image database
Resistance to worming treatments/Anthelminitic resistance
Resistance to the worming products we currently have available is very concerning.
Resistance is the ability of worms inside a horse to survive a worming treatment that was previously effective in killing the worms - i.e. the drugs no longer work effectively.
Why does resistance happen? Every time a horse is treated with a wormer, a selection pressure is applied & the genetic evolution of the parasites being treated is modified. In any group of parasites, some will be susceptible and some, because of natural genetic variation, will be more resistant to deworming treatments used. When the horse is wormed, the susceptible worms are killed and the resistant worms survive, breed and multiply. Some of the resistant worms' offspring will be susceptible to wormers, but every time the horse is wormed and the susceptible worms killed, the % of worms resistant to the drugs used increases, until resistant worms dominant the worm population inside the horse, and ultimately all the worms are resistant. The more frequently a horse is wormed, the quicker resistance develops.
Resistant worms cannot be killed by worming treatments, horses will become ill (and potentially die) and no treatment will be available.
Resistance is increased by:
worming too often
repeatedly using the same wormer (the same worming chemical)
under-dosing
Change is overdue and we are close to the point of no return - horse owners (and vets) must change how their worm horses, and only use wormers when tests indicate worming is necessary, then use the correct wormer at the correct dose.
Resistance to the worming products we currently have available is very concerning.
Resistance is the ability of worms inside a horse to survive a worming treatment that was previously effective in killing the worms - i.e. the drugs no longer work effectively.
Why does resistance happen? Every time a horse is treated with a wormer, a selection pressure is applied & the genetic evolution of the parasites being treated is modified. In any group of parasites, some will be susceptible and some, because of natural genetic variation, will be more resistant to deworming treatments used. When the horse is wormed, the susceptible worms are killed and the resistant worms survive, breed and multiply. Some of the resistant worms' offspring will be susceptible to wormers, but every time the horse is wormed and the susceptible worms killed, the % of worms resistant to the drugs used increases, until resistant worms dominant the worm population inside the horse, and ultimately all the worms are resistant. The more frequently a horse is wormed, the quicker resistance develops.
Resistant worms cannot be killed by worming treatments, horses will become ill (and potentially die) and no treatment will be available.
Resistance is increased by:
worming too often
repeatedly using the same wormer (the same worming chemical)
under-dosing
Change is overdue and we are close to the point of no return - horse owners (and vets) must change how their worm horses, and only use wormers when tests indicate worming is necessary, then use the correct wormer at the correct dose.
Rendle, David
Should wormers be POM-V only, an update
BEVA Congress September 2022 Handbook of presentations p 140 (IVIS)
There is now genuine fear that equine welfare will be compromised by untreatable endoparasitic disease due to increased prevalence of anthelmintic resistance. There is an overdependence on macrocyclic lactones.
Anthelmintics should only be used when there is demonstrable need. There is evidence of toxic effects on the environment from the use of some equine anthelmintics. We should not be using anthelmintics routinely and should not be seeking to eliminate parasites. The withdrawal of the only praziquantel-only wormer (Equitape) has led to owners using combined wormers contrary to best practice - owners should ask their vets for off-label praziquantel if treatment against only tapeworm is needed.
Nielsen, Martin
Anthelmintic resistance - do we really need to worry?
BEVA Congress September 2022 Handbook of presentations p 136 (IVIS)
Nielsen, Martin
How to avoid the pitfalls of faecal worm egg counts and the best way to interpret the results
BEVA Congress September 2022 Handbook of presentations p 220 ((IVIS)
Worm egg counts are useful for:
- evaluating anthelminitic treatment efficacy using the faecal egg count reduction test,
- indentifying low, moderate and high stronglye egg shedders in adult horses,
- identifying Parascaris species infections in foals and young horses.
There is no direct correlation between egg counts and worm counts - more eggs do not equal more worms.
Adult (egg shedding) worms rarely cause parasitic disease - migrating and encysted larvae (which are not detected on an egg count) are more likely to cause disease.
Daniels SP, Leng J, Swann JR, Proudman CJ
Bugs and drugs: a systems biology approach to characterising the effect of moxidectin on the horse's faecal microbiome
Animal Microbiome October 2020 2:38 https://doi.org/10.1186/s42523-020-00056-2
In horses with low parasite burdens, moxidectin had a small but measurable effect on both the community structure and the function of the gut microbiome.
Daniels, Simon Paul
Anthelmintic treatment in horses: efficacy and effects on intestinal health
PhD thesis December 2017 University of Surrey
Steuer AE, Loynachan AT, Nielsen MK
Evaluation of the mucosal inflammatory responses to equine cyathostomins in response to anthelmintic treatment.
Vet Immunol Immunopathol. 2018 May;199:1-7. doi: 10.1016/j.vetimm.2018.02.011. Epub 2018 Mar 6.
JEVS January 2018 Vol 60, Pages 113–119.e1
Analysis of Strongyle Egg Shedding Consistency in Horses and Factors That Affect It
Lester HE, Morgan ER, Hodgkinson JE, Matthews JB
Shea Porr CA, Hedinger VF, Hamm LR, Ernst MM, Papajeski BM, Santiago ML, Davis AJ
Effects of Ivermectin and Moxidectin on Fecal Egg Count and Egg Reappearance Rate in Horses
JEVS October 2017 Vol 57, Pages 51–55
Fecal egg count reduction tests were 100% for ivermectin (IVE) and moxidectin (MOX), "indicating that both anthelmintics were effective. However, parasite eggs began to appear in IVE horses in week 6 and MOX horses in week 8. Currently reported ERP for IVE and MOX are 6 to 8 weeks and 10 to 12 weeks, respectively, suggesting decreased efficacy of MOX. In pastured horses, MOX was more effective in reducing FEC than IVE (1.84 vs. 6.43 EPG, respectively; P = .01). Data suggest that anthelmintic use improved internal parasite control and that MOX may have greater efficacy than IVE; however, the shorter ERP for MOX may indicate that MOX efficacy may be decreasing."
Daniels SP, Proudman CJ
Shortened egg reappearance after ivermectin or moxidectin use in horses in the UK
The Veterinary Journal Volume 218, December 2016, Pages 36–39
This study reports ivermectin and moxidectin egg reappearance periods (ERP) from UK horses with persistently positive faecal egg counts (FEC), defined as positive FEC within the ERP of an anthelmintic post-treatment, or with FECs that remained positive after the normal ERP post-anthelmintic treatment. A selected population of UK pleasure horses deemed at high risk of strongyle infection was studied. The earliest ERP recorded after ivermectin or moxidectin, using first positive FEC, was 5 weeks. From 16 premises where moxidectin was used, five had ERP ≥12 weeks using two further metrics. For premises where moxidectin was administered to only one animal (present or tested), and evaluated as one group (n = 61), ERP was ≥10 weeks. For premises where ivermectin was used, the ERP was ≥5 weeks. Premises with only one horse (present or tested), dosed with ivermectin (n = 31), analysed as one group, demonstrated egg reappearance ≥6 weeks. These field data suggest shortened ERPs following macrocyclic lactone treatment compared to previously published values (8–10 and >13 weeks respectively) when these drugs were first marketed.
Diagnosis and treatment of cyathostominosis in horses - David Rendle, Vet Times, 01 December 2014
Equine Vet J. 2014 Jan;46(1):17-24 (PubMed)
An investigation of anthelmintic efficacy against strongyles on equine yards in Scotland
Stratford CH, Lester HE, Pickles KJ, McGorum BC, Matthews JB
"A total of 447 FECRTs were performed on 15 yards, as follows (the numbers in parentheses represent the number of yards each anthelmintic was tested on): 55 equids (7 yards) fenbendazole, 111 (8 yards) pyrantel, 163 (13 yards) ivermectin and 118 (10 yards) moxidectin. Fenbendazole resistance was documented on all yards (range of mean FECR, 15.8-83.4%), whereas pyrantel (90.4-99.6%), ivermectin (99.5-100%) and moxidectin (99.4-100%) treatment had acceptable efficacy."
Vet Parasitol. 2013 Oct 18;197(1-2):189-96 (PubMed)
Anthelmintic efficacy against cyathostomins in horses in Southern England
Lester HE, Spanton J, Stratford CH, Bartley DJ, Morgan ER, Hodgkinson JE, Coumbe K, Mair T, Swan B, Lemon G, Cookson R, Matthews JB
"As the prevalence of FBZ resistance was 100%, the future use of this anthelmintic for the control of strongyles should be questioned. PYR should be used strategically to reduce reliance on the macrocyclic lactone class products."
Vet Parasitol. 2012 Sep 10;188(3-4):294-300
Efficacy of major anthelmintics against horse cyathostomins in France
Traversa D, Castagna G, von Samson-Himmelstjerna G, Meloni S, Bartolini R, Geurden T, Pearce MC, Woringer E, Besognet B, Milillo P, D'Espois M
Corning S
Equine cyathostomins: a review of biology, clinical significance and therapy
Parasit Vectors. 2009; 2(Suppl 2): S1. Published online 2009 Sep 25. doi: 10.1186/1756-3305-2-S2-S1
K.J. Chandler, M.C.Collins, S.Love.
Efficacy of a five-day course of fenbendazole in benzimidazole- resistant cyathostomes.
Veterinary Record (2000) 147, 661-662
Routine Testing, Not Routine Worming, Should Form the Base of a Good Equine Worm Control Programme - Gillian Booth - International Animal Health Journal 37
Kivipelto J, Nicklin C, Asquith RL
Comparison of Pyrantel Tartrate (Strongid C) and Pyrantel Pamoate (33 Strongid) for the Control of Equine Tapeworms
AAEP Proceedings 1998 Vol. 44
Can worming cause colic or diarrhoea?
From the VMD SPC for Equest Pramox:
"In case of very high worm burdens, destruction of the parasites may cause a mild transient colic and loose faeces in the treated horse."
From the VMD SPC for Eqvalan Duo:
"In cases of heavy infestations with tapeworms, signs of mild, transient colic and loose stool may be observed."
From the VMD SPC for Strongid-P paste:
"Impaction of the small intestine may occur in foals, infected with high numbers of Parascaris equorum. Symptoms (colic) may be seen as soon as 30 minutes after treatment."
The SPCs for Eqvalan and Noromectin (both containing ivermectin only as the active ingredient) do not warn about colic or diarrhoea following worming with these products. The SPC for Equest (containing moxidectin only as the active ingredient) does not warn about colic or diarrhoea. However, it seems likely that the use of an effective worming product could lead to mild, transient colic or diarrhoea in any horse with a high worm burden.
Natural worming products
Wuest S, Atkinson RL, Bland SD, Hastings D
A Pilot Study on the Effects of Curcumin on Parasites, Inflammation, and Opportunistic Bacteria in Riding Horses
JEVS October 2017 Vol 57, Pages 46–50
6 horses were fed 15 g of 95% pure curcumin each day for 30 days and blood and fecal sample results compared to controls. Curcumin treatment had no effect on total fecal egg count, strongyles, or ascarids, erythrocyte sedimentation rate (ESR), although ESR decreased on day 14 in curcumin treated horses. Treatment had no effect on concentrations of Streptococcus bovis/equinus complex, Clostridium difficile, or Clostridium perfringens. "Curcumin was not an effective compound against intestinal parasites or fecal microbial strains examined when administered for 30 days; but could potentially decrease inflammation."
Worming and probiotics
Is there any science suggesting that probiotics should be given when worming horses? Protexin suggest yes, but may be biased!
The importance of probiotics when worming your horse - Liam Gamble, Protexin Veterinary Technical Team
Environmental impacts of worming treatments
Haseler CJ, Shrubb JL, Davies HGD, Rendle DI, Rathbone PC, Mair TS
Environmental impacts of equine parasiticide treatment: The UK perspective
Equine Veterinary Education 2024 00 pages 1-12. https://doi.org/10.1111/eve.13944
Haseler CJ, Shrubb JL, Davies HGD, Rendle DI, Rathbone PC, Mair TS
Environmental impacts of equine parasiticide treatment: The UK perspective
Equine Veterinary Education 2024 00 pages 1-12. https://doi.org/10.1111/eve.13944
Wounds
Any treatment or solution used on a wound or inside a body cavity and coming into contact with live tissue should be effective against infectious organisms/bacteria without damaging healthy tissue or impairing tissue repair.
TLS considers that any treatment used on a horse's foot should be considered safe to use for human surgical lavage/irrigation, if there is any possibility that it could reach live tissue, e.g. if pus or blood are seen on the foot, or if the horse shows any sensitivity to treatments being used.
Choose Equine Wound Debridement Approaches Carefully - Christa Leste-Lasserre www.thehorse.com March 2022
Wound management in horses - Andy Fiske-Jackson Veterinary Practice 01 June 2020
Wound Management in the Horse
Veterinary Clinics of North America: Equine Practice Volume 34, Issue 3, Pages 461-620 (December 2018)
Contents
Leise BS.
Topical Wound Medications.
Vet Clin North Am Equine Pract. 2018 Dec;34(3):485-498. doi: 10.1016/j.cveq.2018.07.006. PMID: 30447767.
Wound treatment in humans/other species
Britto EJ, Nezwek TA, Robins M.
Wound Dressings.
Updated 2022 Apr 30. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470199/
Topical wound treatments/soaking solutions
Below we consider commonly used wound treatments/soaking solutions:
Acetic acid - may be safe to use
Chlorhexidine - considered less effective than povidone-iodine
Hydrogen peroxide H2O2 - do NOT use
Iodine - do NOT use
Povidone-iodine - may be safe to use
Manuka honey - may be safe to use
Saline - may be safe to use
Acetic acid (vinegar)
Vinegar (e.g. apple cider vinegar, white vinegar) is around 5% acetic acid. Acetic acid diluted with sterile water has been shown effective against some bacteria infected chronic wounds (e.g. Pseudomonas aeruginosa), and is easy to source, inexpensive and relatively non-toxic to healthy cells.
Chin JD, Zhao L, Mayberry TG, Cowan BC, Wakefield MR, Fang Y.
Photodynamic Therapy, Probiotics, Acetic Acid, and Essential Oil in the Treatment of Chronic Wounds Infected with Pseudomonas aeruginosa.
Pharmaceutics. 2023; 15(6):1721. https://doi.org/10.3390/pharmaceutics15061721
Chlorhexidine
Chlrohexidine is an antiseptic that has been shown to kill a broad range of bacteria quickly. In vitro chlorhexidine was found to be less effective than povidone-iodine. Irrigation of abdominal surgical sites with 0.05% chlorhexidine resulted in significantly less infection compared to saline.
Hydrogen peroxide H2O2
Hydrogen peroxide is a highly reactive oxidizing agent that is effective against a broad range of microorganisms. Plenty of controversy about whether hydrogen peroxide H2O2 should be used on wounds or not... ER doctor and wound specialist Troy Madsen says don't use hydrogen peroxide on wounds in a 2023 University of Utah Health podcast - hydrogen peroxide may be killing germs, but it may also kill healthy tissue (3% solution has been found to be cytotoxic). The UK Government warned in 2014 that whilst hydrogen peroxide can be used at concentrations up to 6% for disinfectation of minor cuts, wounds and skin ulcers, it must not be used in closed body cavities during surgery or for deep or large wounds, because it can cause potentially fatal gas embolism when used in an enclosed space.
Zhu G, Wang Q, Lu S, Niu Y.
Hydrogen Peroxide: A Potential Wound Therapeutic Target?
Med Princ Pract. 2017;26(4):301-308. doi: 10.1159/000475501. Epub 2017 Apr 5. PMID: 28384636; PMCID: PMC5768111.
3% hydrogen peroxide is used for clinical irrigation of skin wounds, but "no beneficial effect of 3% H2O2 in promoting wound healing has been seen in the literature."
Very low concentrations of H2O2 may be beneficial (e.g. honey).
Murphy EC, Friedman AJ.
Hydrogen peroxide and cutaneous biology: Translational applications, benefits, and risks.
J Am Acad Dermatol. 2019 Dec;81(6):1379-1386. doi: 10.1016/j.jaad.2019.05.030. Epub 2019 May 16. PMID: 31103570.
"In concentrations from 1% to 6%, H2O2 has antimicrobial properties and can act as a debriding agent through its effervescence, making low-concentration H2O2 useful for wound care......However, H2O2 should be used with caution, as exposure can cause adverse effects through its oxidant capabilities. Low H2O2 concentrations cause only transient symptoms (blanching and blistering), but exposure to 9% to 45% H2O2 can cause more severe skin damage, including epidermal necrosis leading to erythema and bullae."
Iodine
Iodine is an antiseptic that is effective against a broad range of bacteria and microorganisms, but on its own iodine is toxic to healthy tissue, and therefore should be used as povidone-iodine.
Sibbald RG, Leaoer DJ, Queen D
Iodine Made Easy
Wounds International 2011; 2(2)
Povidone-iodine
Povidone-iodine (an antiseptic) is a chemical composed of povidone (a water-soluble polymer), hydrogen iodine and elemental iodine. Iodine has been used for years as a broad-spectrum antimicrobial on skin wounds and infections, being effective against Gram+ and Gram- bacteria, fungi and viruses, but iodine can cause irritation and cell toxicity. Povidone-iodine continuously releases small amounts of free iodine, reducing cell toxicity. Paradoxically, increasing the dilution of povidone-iodine increases the concentration of free iodine (as the increased dilution weakens the binding of iodine to the carrier povidone). Povidone-iodine solutions usually contain 10% iodine, e.g. Betadine. Undiluted povidone-iodine should only be used externally - it must be diluted for internal/surgical use.
Paul Lorenz Bigliardi, Syed Abdul Latiff Alsagoff, Hossam Yehia El-Kafrawi, Jai-Kyong Pyon, Chad Tse Cheuk Wa, Martin Anthony Villa
Povidone iodine in wound healing: A review of current concepts and practices
International Journal of Surgery 2017, Vol 44, Pages 260-268, https://doi.org/10.1016/j.ijsu.2017.06.073
"Results and conclusion
Povidone iodine has many characteristics that position it extraordinarily well for wound healing, including its broad antimicrobial spectrum, lack of resistance, efficacy against biofilms, good tolerability and its effect on excessive inflammation. Due to its rapid, potent, broad-spectrum antimicrobial properties, and favorable risk/benefit profile, povidone iodine is expected to remain a highly effective treatment for acute and chronic wounds in the foreseeable future."
Povidone-iodine and chronic ulcers: a great controversy - Dr Elena Conde
Studies on human wounds comparing povidone-iodine with other dressings have found no inferiority in healing rates, and studies of its antimicrobial activity in chronic ulcers have found decreased bacterial growth, but more studies are needed.
Povidone-iodine (Betadine) is often used as an antiseptic, but research has suggested that "caution should be used when povidone-iodine is placed on an open wound", after exposing human fibroblast cells to dilute solutions of povidone-iodine. 0.1% and 1% solutions totally inhibited fibroblast growth, and 0.01% and 0.025% solutions retarded growth.
Balin A, Pratt L
Dilute Povidone-Iodine Solutions Inhibit Human Skin Fibroblast Growth
Dermatologic Surgery April 2002 28(3):210-4. DOI: 10.1046/j.1524-4725.2002.01161.x
Manuka honey
McIver VC, Tsang AS, Symonds NE, Perkins NR, Uquillas E, Dart CM, Jeffcott LB, Dart AJ
Effects of topical treatment of cannabidiol extract in a unique manuka factor 5 manuka honey carrier on second intention wound healing on equine distal limb wounds: a preliminary study
Australian Veterinary Journal June 2020 vol 98 Issue 6. Published online 24 February 2020. https://doi.org/10.1111/avj.12932
Wounds treated with 1% cannabidiol in manuka honey showed no difference in wound healing variables than treatment with saline alone.
"This was unexpected due to the established effects of UMF 20 manuka honey on wound healing using the same model."
Carnwath R, Graham EM, Reynolds K, Pollock PJ
The antimicrobial activity of honey against common equine wound bacterial isolates
The Veterinary Journal January 2014 Vol 199 Issue 1 pages 110-114
Saline
Saline has antiseptic effects and is safe for surgical irrigation, but some research found no benefit of using saline irrigation compared to no irrigation in human abdominal surgery. The most common solution used by vets to clean horse wounds is 0.9% sodium chloride.
Research & Other Information
Marchant K, Hendrickson DA, Pezzanite LM
Review of the role of biofilms in equine wounds: Clinical indications and treatment strategies
Equine Veterinary Education March 2024 Vol 36 Issue 3 pages 152-168. First published 22 November 2023. https://doi.org/10.1111/eve.13919
Papadakis M.
Wound irrigation for preventing surgical site infections.
World J Methodol. 2021 Jul 20;11(4):222-227. doi: 10.5662/wjm.v11.i4.222. PMID: 34322371; PMCID: PMC8299912.
Any treatment or solution used on a wound or inside a body cavity and coming into contact with live tissue should be effective against infectious organisms/bacteria without damaging healthy tissue or impairing tissue repair.
TLS considers that any treatment used on a horse's foot should be considered safe to use for human surgical lavage/irrigation, if there is any possibility that it could reach live tissue, e.g. if pus or blood are seen on the foot, or if the horse shows any sensitivity to treatments being used.
Choose Equine Wound Debridement Approaches Carefully - Christa Leste-Lasserre www.thehorse.com March 2022
Wound management in horses - Andy Fiske-Jackson Veterinary Practice 01 June 2020
Wound Management in the Horse
Veterinary Clinics of North America: Equine Practice Volume 34, Issue 3, Pages 461-620 (December 2018)
Contents
Leise BS.
Topical Wound Medications.
Vet Clin North Am Equine Pract. 2018 Dec;34(3):485-498. doi: 10.1016/j.cveq.2018.07.006. PMID: 30447767.
Wound treatment in humans/other species
Britto EJ, Nezwek TA, Robins M.
Wound Dressings.
Updated 2022 Apr 30. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470199/
Topical wound treatments/soaking solutions
Below we consider commonly used wound treatments/soaking solutions:
Acetic acid - may be safe to use
Chlorhexidine - considered less effective than povidone-iodine
Hydrogen peroxide H2O2 - do NOT use
Iodine - do NOT use
Povidone-iodine - may be safe to use
Manuka honey - may be safe to use
Saline - may be safe to use
Acetic acid (vinegar)
Vinegar (e.g. apple cider vinegar, white vinegar) is around 5% acetic acid. Acetic acid diluted with sterile water has been shown effective against some bacteria infected chronic wounds (e.g. Pseudomonas aeruginosa), and is easy to source, inexpensive and relatively non-toxic to healthy cells.
Chin JD, Zhao L, Mayberry TG, Cowan BC, Wakefield MR, Fang Y.
Photodynamic Therapy, Probiotics, Acetic Acid, and Essential Oil in the Treatment of Chronic Wounds Infected with Pseudomonas aeruginosa.
Pharmaceutics. 2023; 15(6):1721. https://doi.org/10.3390/pharmaceutics15061721
Chlorhexidine
Chlrohexidine is an antiseptic that has been shown to kill a broad range of bacteria quickly. In vitro chlorhexidine was found to be less effective than povidone-iodine. Irrigation of abdominal surgical sites with 0.05% chlorhexidine resulted in significantly less infection compared to saline.
Hydrogen peroxide H2O2
Hydrogen peroxide is a highly reactive oxidizing agent that is effective against a broad range of microorganisms. Plenty of controversy about whether hydrogen peroxide H2O2 should be used on wounds or not... ER doctor and wound specialist Troy Madsen says don't use hydrogen peroxide on wounds in a 2023 University of Utah Health podcast - hydrogen peroxide may be killing germs, but it may also kill healthy tissue (3% solution has been found to be cytotoxic). The UK Government warned in 2014 that whilst hydrogen peroxide can be used at concentrations up to 6% for disinfectation of minor cuts, wounds and skin ulcers, it must not be used in closed body cavities during surgery or for deep or large wounds, because it can cause potentially fatal gas embolism when used in an enclosed space.
Zhu G, Wang Q, Lu S, Niu Y.
Hydrogen Peroxide: A Potential Wound Therapeutic Target?
Med Princ Pract. 2017;26(4):301-308. doi: 10.1159/000475501. Epub 2017 Apr 5. PMID: 28384636; PMCID: PMC5768111.
3% hydrogen peroxide is used for clinical irrigation of skin wounds, but "no beneficial effect of 3% H2O2 in promoting wound healing has been seen in the literature."
Very low concentrations of H2O2 may be beneficial (e.g. honey).
Murphy EC, Friedman AJ.
Hydrogen peroxide and cutaneous biology: Translational applications, benefits, and risks.
J Am Acad Dermatol. 2019 Dec;81(6):1379-1386. doi: 10.1016/j.jaad.2019.05.030. Epub 2019 May 16. PMID: 31103570.
"In concentrations from 1% to 6%, H2O2 has antimicrobial properties and can act as a debriding agent through its effervescence, making low-concentration H2O2 useful for wound care......However, H2O2 should be used with caution, as exposure can cause adverse effects through its oxidant capabilities. Low H2O2 concentrations cause only transient symptoms (blanching and blistering), but exposure to 9% to 45% H2O2 can cause more severe skin damage, including epidermal necrosis leading to erythema and bullae."
Iodine
Iodine is an antiseptic that is effective against a broad range of bacteria and microorganisms, but on its own iodine is toxic to healthy tissue, and therefore should be used as povidone-iodine.
Sibbald RG, Leaoer DJ, Queen D
Iodine Made Easy
Wounds International 2011; 2(2)
Povidone-iodine
Povidone-iodine (an antiseptic) is a chemical composed of povidone (a water-soluble polymer), hydrogen iodine and elemental iodine. Iodine has been used for years as a broad-spectrum antimicrobial on skin wounds and infections, being effective against Gram+ and Gram- bacteria, fungi and viruses, but iodine can cause irritation and cell toxicity. Povidone-iodine continuously releases small amounts of free iodine, reducing cell toxicity. Paradoxically, increasing the dilution of povidone-iodine increases the concentration of free iodine (as the increased dilution weakens the binding of iodine to the carrier povidone). Povidone-iodine solutions usually contain 10% iodine, e.g. Betadine. Undiluted povidone-iodine should only be used externally - it must be diluted for internal/surgical use.
Paul Lorenz Bigliardi, Syed Abdul Latiff Alsagoff, Hossam Yehia El-Kafrawi, Jai-Kyong Pyon, Chad Tse Cheuk Wa, Martin Anthony Villa
Povidone iodine in wound healing: A review of current concepts and practices
International Journal of Surgery 2017, Vol 44, Pages 260-268, https://doi.org/10.1016/j.ijsu.2017.06.073
"Results and conclusion
Povidone iodine has many characteristics that position it extraordinarily well for wound healing, including its broad antimicrobial spectrum, lack of resistance, efficacy against biofilms, good tolerability and its effect on excessive inflammation. Due to its rapid, potent, broad-spectrum antimicrobial properties, and favorable risk/benefit profile, povidone iodine is expected to remain a highly effective treatment for acute and chronic wounds in the foreseeable future."
Povidone-iodine and chronic ulcers: a great controversy - Dr Elena Conde
Studies on human wounds comparing povidone-iodine with other dressings have found no inferiority in healing rates, and studies of its antimicrobial activity in chronic ulcers have found decreased bacterial growth, but more studies are needed.
Povidone-iodine (Betadine) is often used as an antiseptic, but research has suggested that "caution should be used when povidone-iodine is placed on an open wound", after exposing human fibroblast cells to dilute solutions of povidone-iodine. 0.1% and 1% solutions totally inhibited fibroblast growth, and 0.01% and 0.025% solutions retarded growth.
Balin A, Pratt L
Dilute Povidone-Iodine Solutions Inhibit Human Skin Fibroblast Growth
Dermatologic Surgery April 2002 28(3):210-4. DOI: 10.1046/j.1524-4725.2002.01161.x
Manuka honey
McIver VC, Tsang AS, Symonds NE, Perkins NR, Uquillas E, Dart CM, Jeffcott LB, Dart AJ
Effects of topical treatment of cannabidiol extract in a unique manuka factor 5 manuka honey carrier on second intention wound healing on equine distal limb wounds: a preliminary study
Australian Veterinary Journal June 2020 vol 98 Issue 6. Published online 24 February 2020. https://doi.org/10.1111/avj.12932
Wounds treated with 1% cannabidiol in manuka honey showed no difference in wound healing variables than treatment with saline alone.
"This was unexpected due to the established effects of UMF 20 manuka honey on wound healing using the same model."
Carnwath R, Graham EM, Reynolds K, Pollock PJ
The antimicrobial activity of honey against common equine wound bacterial isolates
The Veterinary Journal January 2014 Vol 199 Issue 1 pages 110-114
Saline
Saline has antiseptic effects and is safe for surgical irrigation, but some research found no benefit of using saline irrigation compared to no irrigation in human abdominal surgery. The most common solution used by vets to clean horse wounds is 0.9% sodium chloride.
Research & Other Information
Marchant K, Hendrickson DA, Pezzanite LM
Review of the role of biofilms in equine wounds: Clinical indications and treatment strategies
Equine Veterinary Education March 2024 Vol 36 Issue 3 pages 152-168. First published 22 November 2023. https://doi.org/10.1111/eve.13919
Papadakis M.
Wound irrigation for preventing surgical site infections.
World J Methodol. 2021 Jul 20;11(4):222-227. doi: 10.5662/wjm.v11.i4.222. PMID: 34322371; PMCID: PMC8299912.