The OAHN Equine page is dedicated to sharing accurate information for equine owners and vets.
Ontario Equine Disease Alerts Update - Sep 5
-Strangles found in Ottawa, Leeds & Grenville
-EEE in Parry Sound, Leeds & Grenville, Ottawa
-West Nile in Simcoe County, Prescott & Russell
Details and full list:
https://www.oahn.ca/resources/ontario-equine-disease-alerts/
SEVEN CROWS, ONE BLUE JAY and ONE RAVEN test positive for WEST NILE VIRUS
Have you vaccinated your HORSE against West Nile Virus?
NINE deceased wild birds from:
STITTSVILLE
INGERSOLL
WELLAND
PETERBOROUGH
SAULT STE MARIE
KINGSTON
CARDINAL
TIMMONS
SUDBURY
and submitted to the Canadian Wildlife Health Cooperative (August 2024), have tested positive for West Nile virus (WNV).
In Ontario, horses are diagnosed with WNV from July through October, depending on the environmental conditions.
Don’t wait to vaccinate! Contact your veterinarian today!
For more information on WNV surveillance in wild birds, go to https://www.cwhc-rcsf.ca/west_nile_virus.php
Please contact the CWHC regional centre in your area to report dead wildlife - see https://www.cwhc-rcsf.ca/report_and_submit.php for more information.
Ontario Equine Disease Alerts Update
1 new case of EEE in Lanark County
1 new case of WNV in Norfolk County.
More details and full list here:
https://www.oahn.ca/resources/ontario-equine-disease-alerts/
SIX CROWS and TWO BLUE JAYS test positive for WEST NILE VIRUS in ONTARIO
Have you vaccinated your HORSE against West Nile Virus?
EIGHT deceased wild birds from:
CASSELMAN (2)
EAR FALLS
ETOBICOKE
GEORGIAN BLUFFS
THUNDER BAY
WATERLOO (2)
and submitted to the Canadian Wildlife Health Cooperative (August 2024), have tested positive for West Nile virus (WNV).
In Ontario, horses are diagnosed with WNV from July through October, depending on the environmental conditions.
Don’t wait to vaccinate! Contact your veterinarian today!
For more information on WNV surveillance in wild birds, go to https://www.cwhc-rcsf.ca/west_nile_virus.php
Please contact the CWHC regional centre in your area to report dead wildlife - see https://www.cwhc-rcsf.ca/report_and_submit.php for more information.
Ontario Equine Disease Alerts Update
New cases of Eastern Equine Encephalitis reported in Leeds and Grenville (2), and Lanark County. More details and full list of equine disease alerts here:
https://www.oahn.ca/resources/ontario-equine-disease-alerts/
Aug 16th Ontario Equine Disease Alerts
Eastern Equine Encephalitis found in
United Counties of Leeds and Grenville
City of Ottawa
Lanark County
Read more about the cases, and get resources here:
https://www.oahn.ca/resources/ontario-equine-disease-alerts/
FOUR AMERICAN CROWS, TWO RED-TAILED HAWKS, ONE BLUE JAY and ONE LOGGERHEAD STRIKE test positive for WEST NILE VIRUS
Have you vaccinated your HORSE against West Nile Virus?
EIGHT deceased birds from the following areas,
BOBCAYGEON
BURLINGTON
HAMILTON (2)
KINGSTON
LONDON
NIAGARA-ON-THE-LAKE
SARNIA
and submitted to the Canadian Wildlife Health Cooperative (July/August 2024), have tested positive for West Nile virus (WNV).
In Ontario, horses are diagnosed with WNV from July through October, depending on the environmental conditions.
Don’t wait to vaccinate! Contact your veterinarian today!
For more information on WNV surveillance in wild birds, go to https://www.cwhc-rcsf.ca/west_nile_virus.php
Please contact the CWHC regional centre in your area to report dead wildlife - see https://www.cwhc-rcsf.ca/report_and_submit.php for more information.
Ontario Equine Disease Alert: Eastern Equine Encephalitis in United Counties of Leeds and Grenville, ON.
More details and list of ON equine disease alerts available here:
https://www.oahn.ca/resources/ontario-equine-disease-alerts/
WEST NILE VIRUS (WNV) surveillance is a great example of a ONE HEALTH tool.
Public Health Ontario does surveillance on mosquito pools in urban areas within each health unit for the presence of WNV. They also report the number of human cases of WNV by health unit. They report these results weekly from July to October: https://www.publichealthontario.ca/en/Data-and-Analysis/Infectious-Disease/West-Nile-Virus
As WNV in horses is both a federally and provincially immediately notifiable disease, the Canadian Food Inspection Agency and Ontario Ministry of Agriculture, Food and Agribusiness (OMAFA) receive positive laboratory test results for WNV in horses. The CFIA reports them to the Canadian Animal Health Surveillance System (CAHSS) and they are posted on the CAHSS equine disease dashboard: https://cahss.ca/cahss-networks/equine
The Ontario WNV equine cases are posted through our OAHN equine portal: https://www.oahn.ca/resources/ontario-equine-disease-alerts/
If we graph the number of positives over the years, one can see a concomitant increase in positive mosquito pools, humans and horses during certain years (please note that the equine cases (orange line) are represented by the axis on the right). This is why as veterinarians and horse custodians, monitoring what is happening in mosquitoes and humans can give us an idea of the WNV risk to our horses.
Fortunately horses have an extremely effective vaccine to protect them. People do not.
Discuss WNV vaccination with your veterinarian today!
NINE CROWS and a BLUE JAY test positive for WEST NILE VIRUS
Have you vaccinated your HORSE against West Nile Virus?
NINE deceased CROWS from:
ALEXANDRIA
BURLINGTON
KING CITY
NEPEAN
SAULT STE MARIE
STRATHROY
WINGHAM
THUNDER BAY (2 CROWS SUBMITTED)
and a BLUE JAY from LONDON
and submitted to the Canadian Wildlife Health Cooperative (AUGUST 2024), have tested positive for West Nile virus (WNV).
In Ontario, horses are diagnosed with WNV from July through October, depending on the environmental conditions.
Don’t wait to vaccinate! Contact your veterinarian today!
For more information on WNV surveillance in wild birds, go to https://www.cwhc-rcsf.ca/west_nile_virus.php
Please contact the CWHC regional centre in your area to report dead wildlife - see https://www.cwhc-rcsf.ca/report_and_submit.php for more information.
A RED-TAILED HAWK in WHITBY
A MERLIN in NEW LISKEARD
And TWO CROWS in LONDON and ETOBICOKE
test positive for WEST NILE VIRUS
Have you vaccinated your HORSE against West Nile Virus?
Deceased BIRDS from the Whitby, New Liskeard, London and Etobicoke, ONTARIO areas and submitted to the Canadian Wildlife Health Cooperative (July 2024), have tested positive for West Nile virus (WNV).
In Ontario, horses are diagnosed with WNV from July through October, depending on the environmental conditions.
Don’t wait to vaccinate! Contact your veterinarian today!
For more information on WNV surveillance in wild birds, go to https://www.cwhc-rcsf.ca/west_nile_virus.php
Please contact the CWHC regional centre in your area to report dead wildlife - see https://www.cwhc-rcsf.ca/report_and_submit.php for more information.
Tapeworms in Horses – Is there anthelmintic resistance developing?
In a recent journal article, Dr. Martin Nielson reported on the potential development of resistance of the equine tapeworm Anoplocephala perfoliata to the anthelmintics praziquantel and pyrantel pamoate. Actual resistance could not be demonstrated because of the lack of a f***l egg count reduction test (FECRT) appropriate for tapeworm studies in the field. As a reminder, f***l egg count (FEC) tests lose sensitivity when worm burdens are low therefore the f***l egg count reduction test (FECRT), which relies on pre- and post-treatment FECs, becomes unreliable. In this report, Nielsen states that he embarked on this study due to “reports from veterinarians in central Kentucky of apparent failure to eliminate A. perfoliata eggs treated with either anthelmintic.” After evaluating pre- and post- anthelmintic treatment in Thoroughbred yearlings and mares at two facilities, Nielsen found a loss of efficacy for both pyrantel and praziquantel in both age groups of horses. This loss in efficacy may have been due to a lack of FEC monitoring and the challenges with f***l egg detection in tapeworms using current on-farm and more popular laboratory techniques. Treatment failure with pyrantel and praziquantel has also been observed in the United Kingdom .
Apparent treatment failure of praziquantel and pyrantel pamoate against anoplocephalid tapeworms. Nielsen MK. Int J Parasitol Drugs Drug Resist. 2023 Aug;22:96-101.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10331019/pdf/main.pdf
• Study Focus: The paper investigates the apparent treatment failure of praziquantel and pyrantel pamoate against anoplocephalid tapeworms in horses.
• Key Findings: The study found low efficacy of both drugs, with praziquantel showing a 23.5% reduction in f***l egg counts and pyrantel pamoate showing a 50.9% reduction.
• Implications: These findings suggest a possible development of anthelmintic resistance in Anoplocephala perfoliata, raising concerns about the need for alternative treatment options.
A VACCINATION for HIVES?
Researchers from Switzerland have developed a vaccination against interleukin-5 (IL-5) a key cytokine that has a main role in the development, survival and activity of eosinophils ( a type of white blood cell important in the development of urticaria or hives). They found that horses that received the vaccination no longer developed urticaria (hives). After the initial booster series, the vaccine is administered annually. The vaccine is still in the research phase and not yet commercially available.
Eosinophils Play a Surprising Leading Role in Recurrent Urticaria in Horses.
Birkmann K, Jebbawi F, Waldern N, Hug S, Inversini V, Keller G, Holm A, Grest P, Canonica F, Schmid-Grendelmeier P, Fettelschoss-Gabriel A. Vaccines (Basel). 2024 May 21;12(6):562.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11209473/
• Study Focus: The study investigates the role of eosinophils in recurrent urticaria in horses and explores the potential of the eIL-5-CuMV-TT vaccine as a treatment.
• Findings: Eosinophils were found to play a significant role in urticaria, and the vaccine reduced eosinophil counts, cleared clinical signs, and prevented new episodes of urticaria.
• Methodology: The study involved skin punch biopsies, gene expression analysis, and vaccination trials with horses affected by non-seasonal urticaria.
• Implications: Targeting eosinophils offers a promising new treatment option for managing urticaria in horses, potentially replacing corticosteroids.
Ontario Equine Disease Alert Update
1 new case of EEE found in Lanark County. List of Ontario equine disease alerts and details available here:
https://www.oahn.ca/resources/ontario-equine-disease-alerts/
Ontario Equine Vets and RVTs!
Last chance to contribute to the quarterly Ontario equine practitioner survey.
We will close the survey Thursday morning.
Thanks to those that have already contributed!
https://uoguelph.eu.qualtrics.com/jfe/form/SV_02prFsZylIUYmrA (link in bio)
Strangles versus S. equi positive horses
It may seem like semantics, but there IS a difference between a horse having Strangles and a horse that is Streptococcus equi positive.
A horse with Strangles has CLINICAL SIGNS of disease such as a fever, nasal discharge, and/or lymph node abscessation (usually of the head and neck) AND tests positive for S. equi either by PCR or bacterial culture. These horses can spread the disease quickly to other horses. At least four weeks after resolution of clinical signs, these horses should be tested for S. equi to determine they have not become a carrier.
In Ontario, horses with STRANGLES are reported to the Equine Disease Communication Center.
Horses that are tested for S. equi prior to moving between boarding facilities, for example, may be S. equi positive. They have NO clinical signs of infection and DO NOT have STRANGLES. Often (but not always) these horses are PCR positive and bacterial culture NEGATIVE. This means there aren’t enough LIVE bacteria to grow in culture. These horses are either CARRIERS of S. equi OR were recently exposed to a carrier horse and are transiently infected. If a repeat test done at least a week later remains positive, however, it is likely the horse is a carrier and ideally their guttural pouches should be evaluated/treated. These horses may not be an immediate concern to horses at their present location, however, ideally they should not be mixed with NEW horses until further evaluated. Often these horses have no known history of Strangles and have been turned out for years with other horses with none of them developing disease. This may mean that their own immune systems are able to control the bacterial load and prevent it from causing disease in other horses, they may be carrying a “less-virulent” strain of S. equi or that their pasture-mates have strong immune responses to S. equi.
Quarantine new horses for 21 days to ensure they have not been acutely infected with S. equi. Any horse developing signs of respiratory infection and/or arriving from higher risk places (eg. livestock auctions, horse dealers, crowded yards, facilities or farms with an unknown health status) should be tested.
A BLUE JAY in SUTTON WEST tests positive for WEST NILE VIRUS
Have you vaccinated your HORSE against West Nile Virus?
A deceased Blue Jay from the Sutton West, ONTARIO area and submitted to the Canadian Wildlife Health Cooperative (July 2024), has tested positive for West Nile virus (WNV).
In Ontario, horses are diagnosed with WNV from July through October, depending on the environmental conditions.
Don’t wait to vaccinate! Contact your veterinarian today!
For more information on WNV surveillance in wild birds, go to https://www.cwhc-rcsf.ca/west_nile_virus.php
Please contact the CWHC regional centre in your area to report dead wildlife - see https://www.cwhc-rcsf.ca/report_and_submit.php for more information.
Giving oral electrolyte solutions to horses can address the fluid and ion losses that occur during moderate intensity exercise.
• Study Focus: The study investigates the effects of pre-loading oral electrolytes on acid-base variables in exercising horses.
• Key Findings: Small volumes (1 and 3 L) of electrolyte solution had minimal effects, while 8 L abolished mild alkalosis during prolonged exercise.
• Methodology: Four horses were given different volumes of water or electrolyte solution before treadmill exercise, and blood samples were analyzed.
• Conclusion: Pre-exercise electrolyte supplementation can mitigate exercise-induced acid-base disturbances.
Read the full paper here:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9817799/pdf/animals-13-00073.pdf
Tracing Acid-Base Variables in Exercising Horses: Effects of Pre-Loading Oral Electrolytes. Waller AP, Lindinger MI. Animals (Basel). 2022 Dec 24;13(1):73.
Don't forget to visit the ResearchONequine.ca website and explore the equine research taking place in Ontario!
Check out our handy one-pager on controlling the spread of Strangles on your farm/facility.
https://www.oahn.ca/wp-content/uploads/2024/05/Biosecurity-procedures-for-Strangles-colour_HG-AM.pdf (both colour and black & white pages are available)
West Nile virus (WNV) is a mosquito-borne flavivirus. WNV primarily causes disease in birds, humans, and horses and is transmitted by many different species of mosquitoes. Since 1999, more than 27,600 U.S. horses have been confirmed with WNV neuro-invasive disease with an estimated average case fata...
Culex pipens, the mosquito that transmits West Nile Virus in Ontario, breeds in standing water located .....well .....anywhere.
Remove the Source and Vaccinate your Horse!
Ontario Equine Vets and RVTs
Please take 5 mins to contribute to the quarterly equine veterinary survey. Your responses help with Ontario equine health and disease surveillance, and influence in choosing research projects.
https://uoguelph.eu.qualtrics.com/jfe/form/SV_02prFsZylIUYmrA
ENDOMETRITIS in MARES
Getting mares in foal (pregnant) can be a tricky business particularly for mare’s that have had previous foals.
Endometritis (inflammation of the inner lining of the uterus or the endometrium) is a common issue in mares that affects fertility. It can also be very challenging for veterinarians to diagnose, usually requiring combinations of different tests such as cytology (examining the cells lining the uterus), bacterial culture, and, for chronic conditions such as endometrial fibrosis (scarring), a biopsy of the endometrium.
These tests can be affected by different sampling techniques and the physiologic state of the mare and can be invasive (biopsy), time-consuming and expensive.
Therefore, researchers from Cornell University and the University of Guelph set out to investigate a new diagnostic test that was efficient and could reliably differentiate a healthy endometrium from acute endometritis and chronic endometrial fibrosis (CEF).
They evaluated 46 mares of various ages, breeds and reproductive status. The concentrations of inflammatory cytokines and chemokines (products secreted by immune system cells that affect other cells) was determined in uterine fluid samples, obtained by low volume lavage, as potential biomarkers of endometritis.
They found that there were significant differences in inflammatory markers between groups allowing the researchers to distinguish between healthy mares, mares with acute endometritis and mares with CEF. They also identified a few inflammatory markers that could distinguish between mares with CEF and those that are reproductively healthy. The cytokine assay used in this study could help with screening mares prior to breeding or be used to support doing an endometrial biopsy for further analysis and to provide a prognosis.
Inflammatory markers for differentiation of endometritis in the mare.
Lection J, Wagner B, Byron M, Miller A, Rollins A, CHENIER T, Cheong SH, Diel de Amorim M. Equine Vet J. 2024 Jul;56(4):678-687.
https://pubmed.ncbi.nlm.nih.gov/38219734/
Don't forget to visit the ResearchONequine.ca website and explore the equine research taking place in Ontario!
STREPTOCOCCUS EQUI M protein ANTIBODY TESTING (SEM ELISA)
The Streptococcus equi (S. equi) M protein ELISA antibody test (SEM ELISA) is offered by some animal health laboratories in Canada.
This is a blood test that measures antibody levels in the horse's blood to the M protein of Streptococcus equi (the causative agent of Strangles).
It DOES NOT detect CARRIER horses! We all wish there was a blood test that was available to detect S. equi carrier horses, but alas, this is not one of them. There is no test available in North America presently to do this and there is no test yet worldwide that can detect carrier horses with appropriate sensitivity.
Why use the SEM ELISA test?
Because it detects the level of S. equi antibodies in the blood, the main uses of this test are to:
- Identify horses that produce high levels of antibodies to S. equi. These horses are often called "hyperresponders" , meaning they have responded to previous S. equi vaccination or infection by producing a "higher than normal" level of antibody. These horses are at risk of developing purpura hemorrhagica (an immune mediated skin disease) if vaccinated against or exposed to S. equi. It is recommended that horses with a known history of Strangles or purpura be tested using the SEM ELISA prior to vaccination and any a horse with an SEM titre greater than 1:1600 should NOT be vaccinated.
- Identify horses with existing purpura hemorrhagica or that have "bastard" or metastatic strangles. These latter horses have had clinical strangles at some point and have developed internal abscesses, usually in the abdomen or chest (but can be anywhere). Horses with metastatic abscesses usually have titres greater than 1:12,800.
- In some situations, this test may be used to determine if a horse has recently been exposed to S. equi. It does not mean the horse is currently infected though.
-This test may also indicate the need for S. equi vaccination based on a very low or absent titre.
Consult with your veterinarian if you have questions about Strangles or SEM testing!
CARDIAC MONITORING of CHUCKWAGON horses at the CALGARY STAMPEDE
For the first time at the Calgary Stampede, every horse running in a chuckwagon race will be tested for cardiac troponin T concentrations in the blood to try and prevent heart attacks!
https://globalnews.ca/news/10595036/new-university-of-calgary-research-looks-to-help-stampede-animals/
Cardiac troponins are biomarkers that can indicate damage to heart muscle cells and have been used in both human and veterinary medicine for decades. In humans, it is a marker of acute myocardial infarction (heart attack). In equine athletes, cardiac troponins can increase as a result of intense exercise as well.
In 2018 Dr. Renaud Leguillette and his team from the University of Calgary completed a study on developing the normal range of a highly sensitive troponin called "cardiac troponin T" (cTnT) in racehorses before and after chuckwagon races at the Calgary Stampede (high intensity/short duration exercise). Knowing the normal range will help veterinarians determine when there is actual heart pathology occurring and potentially prevent sudden deaths.
The team found that chuckwagon horses had a significant increase in cTnT concentration, peaking at 3 hours post-race. The magnitude of the increase was fairly uniform amongst all horses indicating a similar response to the same amount of exercise which is also seen in human exercise physiology with respect to cTnT.
Based on their results, the researchers recommend that chuckwagon horses should be sampled between 2-6 hours after exercise, with a second sample taken between 12 and 24 hours postrace when cTnT returns to normal. Any deviation from the normal values, as determined in this study, could indicate that the horse may have pre-existing heart disease or the intensity /duration of exercise induced heart damage in that particular individual, both requiring further evaluation.
The cTnT test is also being used by the Hong Kong jockey club to monitor thoroughbred racehorses!
Further research in the area is ongoing.
To read the full research article go here:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5787185/
A CROW in the OTTAWA area tests positive for WEST NILE VIRUS
Have you vaccinated your HORSE against West Nile Virus?
A deceased crow from the OTTAWA, ONTARIO area and submitted to the Canadian Wildlife Health Cooperative (June 2024), has tested positive for West Nile virus (WNV).
In Ontario, horses are diagnosed with WNV from July through October, depending on the environmental conditions.
Don’t wait to vaccinate! Contact your veterinarian today!
For more information on WNV surveillance in wild birds, go to https://www.cwhc-rcsf.ca/west_nile_virus.php
Please contact the CWHC regional centre in your area to report dead wildlife - see https://www.cwhc-rcsf.ca/report_and_submit.php for more information.
ATTN: Ontario Equine Vets and RVTs - we want to hear from you!
Please tell us what you've seen in practice over the past 3 months:
https://uoguelph.eu.qualtrics.com/jfe/form/SV_02prFsZylIUYmrA
or scan the QR code below.
Thank you for contributing to Ontario equine health and disease surveillance. We appreciate your time!
HABRONEMIASIS or SUMMER SORES
Nasty skin lesions called "summer sores" or "habronemiasis" are caused by the parasites Habronema microstoma, Habronema muscae or Draschia megastoma and we occasionally we see these lesions in Ontario horses!
The disease is typically seen in temperate to tropical regions, peaking in the summer months and can recur yearly in susceptible animals.
The adults parasite lives in the stomach where it releases eggs that can hatch into larvae during intestinal transit and are passed into the manure. Eggs and larvae are ingested by stable and house flies. Habronema sp develop inside the fly over the course of a week and the L3 larvae are deposited during warm weather around the horse's lips and then swallowed.
The skin form - L3 larvae can also be deposited around the eyes, nostrils, ge***al mucosa, or on the legs (chest, fetlock and inner side of the legs are most common). Lesions are often itchy, ulcerated with pus and or calcified granules. Lesions can have pus or be dry (circular with no hair and grayish scales).
They can also be deposited in wounds where they cause hypersensitivity reactions.
Diagnosis is made by clinical history and skin biopsy.
Treatment is focused on reducing inflammation and using appropriate parasiticides.
Prevention is focused on regular manure removal and disposal and methods to control flies in the environment and on the horse.
Consult with your veterinarian if you think your horse may have summer sores!
Ontario Equine Disease Alert - Equine Influenza in Simcoe County. More info and full list of ON equine disease alerts available here:
https://www.oahn.ca/resources/ontario-equine-disease-alerts/
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Ontario Equine Vets and RVTs Please take 5 mins to contribute to the quarterly equine veterinary survey. Your responses help with Ontario equine health and disease surveillance, and influence in choosing research projects. https://uoguelph.eu.qualtrics.com/jfe/form/SV_02prFsZylIUYmrA #OntarioEquine #OntarioHorse
To determine if a horse is a carrier of Streptococcus equi (the bacterium that causes Strangles), the guttural pouches are often evaluated by endoscopy. Here is a short video of a normal guttural pouch (compliments of Grossenbacher Equine Services). Can you see the pulsating external carotid artery? #stopthespreadofstrangles #stranglesawarenessweek2024 #stopthestigmaofstrangles
REMINDER: Ontario Equine Vets - Please take 5 mins to fill this out. Your responses help with equine disease surveillance and welfare in Ontario. Thank you! https://uoguelph.eu.qualtrics.com/jfe/form/SV_bIoCBbzPrE9I2N0 #Equine #EquineVet #OntarioHorse #OntarioEquine #HorseVet
OAHN Equine Veterinary Survey Now Available Please take 5 mins to fill out this survey for Ontario Equine Vets. Your responses help with equine disease surveillance and welfare in Ontario. Thank you for your time! https://uoguelph.eu.qualtrics.com/jfe/form/SV_bIoCBbzPrE9I2N0 #Equine #EquineVet #OntarioHorse #OntarioEquine #HorseVet #OntarioVet #VetMed #Veterinary
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