Equine Reproduction News
New Veterinary Teaching University in Texas, USA!
For the first time in over a century, Texas is opening a new veterinary teaching hospital. In response to an increased demand for more veterinarians, Texas Tech University is opening a vet school at the Texas Tech University Health Sciences Center in Amarillo. Around 40% of veterinarians in Texas are 60 years of age or older. In 2017, there were almost 600 applicants at Texas’ established veterinary medicine program, with only 142 places being made available and enrolled. Other applicants had to either leave the state or drop the idea of becoming a veterinarian. With over $17 million made available to complete the project, and ground now broken, the Texas Tech University School of Veterinary Medicine is expected to enroll its first class in Fall 2021.
IMPORTANT NOTICE FOR BREEDERS IN CANADA!
Zoetis Canada has stopped production of the Equine Arteritis Vaccine “Arvac”. We have been advised that the item is “discontinued” and that there is no intention to recommence production.
Given that there are EAV-positive and shedding stallions in Canada, this is a bad situation for North American breeders. Canada has a low incidence of EVA, but – as with any disease – if controls are not in place, there can always be an outbreak. To give you an idea of the effect of such a outbreak, one can look at the results of the 2006 outbreak which originated in New Mexico, USA. Two stallions were identified as “shedders” on the index farm – and this identification occurred only by accident when the farm’s own broodmare band exhibited a low pregnancy rate at their 60 day check. Both stallions were shipping semen. By the time the outbreak was identified and brought under control, an estimated 2,022 horses housed in 50 different facilities in 19 different states were affected – note “affected”, not “infected”, meaning that they had been exposed and consequently were placed under observation and quarantine. Some of those animals did indeed become EAV-seropositive (although we do not know if stallions were affected), and new regulations for shipping semen were introduced into Montana, Washington, Idaho and Oregon states. This was from a single incident, so the implications are significant.
For mare owners breeding to an EAV-positive and shedding stallion, this presents an additional complication to the breeding process if the mare is not current on vaccination. An unvaccinated (or low-titre) mare will be highly likely to contract the disease if bred to an EAV-positive and shedding stallion. While she herself will have no reduction in pregnancy establishment or maintenance rates, if she is exposed to other pregnant mares or a stallion within the 4 weeks or so of contracting the disease, she herself is in a “shedding” state through oronasal secretions, and this route of infection carries a high rate of infection for other pregnant mares (with a high likelihood of subsequent abortion for those mares) or stallions. It is therefore essential that mares bred to an EAV-positive and shedding stallion be kept isolated from susceptible stock following the breeding process, and for an additional 28 days. Neonatal foals at foot for the mare being bred also face increased risk of infection, and although in the case of colt foals development of “shedding” status is not a concern at that age (it requires elevated testosterone levels in order to develop shedding status, which colts prior to puberty will not have), in rare instances – particularly with already sick or debilitated foals – it could prove fatal.
For owners of unvaccinated stallions or those with low titres, it is essential that they do not allow exposure to a mare in the active (acute) stages of the disease, as a stallion in that category could become infected and subsequently a permanent shedder. The stallion is the natural reservoir for the virus. This situation could in particular occur with a mare which has been previously bred to a shedder stallion, failed to become pregnant, and then on the next cycle is presented for breeding to the naive stallion.
From a scientific perspective, although mares bred to shedder stallions will develop naturally elevated antibodies (and therefore immunity), there is an increased risk of mutation of the virus. Currently with Arvac, we in North America (now only the USA) have a good vaccine which protects against the strains present. If a mutation occurs however, this protection may no longer be present.
We have several articles and a presentation regarding Equine Viral Arteritis on the website in the articles section – they are towards the foot of the page.
Equine Reproduction Receives Welcome Boost in the UK
Equine reproduction in the UK has received a boost in that noted specialist Dr. Jonathan Pycock is now BEVA (British Equine Veterinary Association) president. Dr. Pycock is encouraging increased research and presentation of the subject, and an enjoyable first step is the Equine Veterinary Journal’s release of 10 papers viewable on-line by all. These are available on the EVJ website.
Dr. Pycock has been a long-time supporter of Equine-Reproduction.com and has kindly provided us with articles and presentations for many years, some of which can be found in our articles section. We are proud and happy to offer our congratulations to Dr. Pycock, and British horse breeding, as well as our thanks for his support. We must also offer thanks to his wife Gill for provision of the accompanying photo of Dr. Pycock!