Horse news and views

Submitted by Gary Sliworsky
Ag. Rep.

Following is the latest Horse News and Views which is prepared by Dr. Bob Wright, Animal Health and Welfare, OMAFRA, in cooperation with the staff and researchers of the University of Guelph.
The monthly column highlights research topics, extension resources, reminders of common poisonings, disease or production concerns and coming events and is placed on our website, http://www.omafra.gov.on.ca/english/livestock/horses/news.html.
Dr. David Powell of the Maxwell H. Gluck Equine Research Centre, University of Kentucky, reminds horse owners to take a horse’s temperature twice daily if they suspect their horse has come in contact with a horse with an infectious disease. It is a simple means of determining an animal’s health status. (Equine Disease Quarterly, April 2006).
The rectal temperature of horses typically rises 12 - 24 hours prior to the onset of clinical signs of a disease. Temperature taking is a useful procedure regardless of the disease. The onset of signs after exposure is variable and depends on immune status from either previous exposure or vaccination and challenge dose.
Horses exposed to the neurological form of equine herpes (EHV-1), other respiratory viruses or strangles should have their rectal temperature monitored for at least the time equal to or, preferably, twice the maximum incubation period of the disease. This will provide an early warning sign of pending or overt disease and allow for isolation of the affected horse(s). The incubation period for most of the bacterial and viral agents varies from 3 - 14 days (influenza - 1- 10 days; strangles - 3 - 14 days; EHV-1 - 2 - 10 days).
At speaking engagements throughout Ontario, horse owners ask whether it is still worthwhile to vaccinate their horses for West Nile virus (WNv). Looking at surveillance data in Ontario from 2005 (5 cases) and 2006 (3 cases) and in Kentucky (9 cases) from 2005, the horses identified with WNv had either not been vaccinated against WNv or no information was available on their vaccination status.
No WNv cases were detected in horses known to have been properly vaccinated with a WNv vaccine. WNv vaccine is a recommended core vaccine for horses in Ontario as well as many areas of North America.

For further information, contact Dr. Bob Wright (519) 846-3412 or visit our
website: http://www.omafra.gov.on.ca/english/livestock