Equine Herpes Reported In Ontario

Published: April 10, 2021 06:33 pm EDT

Trot Insider has learned that two additional cases of equine herpes virus have been reported in Ontario over the past week.

A draft-breed cross mare in Northumberland County is being treated at a referral hospital after exhibiting ataxia, and having difficulty urinating. No other horses on the property are showing clinical signs. Under veterinary supervision, the facility manager has instituted biosecurity protocols and animal movement restrictions.

In York Region, a 23-year-old mare aborted at 315 days of gestation as a result of EHV. The affected mare has been isolated on the property. No other mares are affected at this time. Under veterinary supervision, the facility manager has implemented biosecurity protocols and animal movement restrictions.

EHV-1 does not pose a threat to public health or food safety. EHV-1 infection is immediately notifiable by laboratories to OMAFRA under the Animal Health Act.

Attending veterinarians concerned about potential cases of EHV-1 infection may contact an OMAFRA veterinarian through the Agricultural Information Contact Centre at 1-877-424-1300.

Because a fever (greater than 101.5 °F or 38.6 °C) may be the first indication of infection, the temperature of potentially exposed animals should be monitored and recorded twice daily for 21 days and any abnormalities discussed with a veterinarian. Neurological signs, if they develop, may include loss of balance, hind-limb weakness, difficulty urinating, decreased tail tone, depression and being down and unable to rise. It is important that a veterinarian assess horses demonstrating neurological signs since it can be difficult to distinguish this from other serious diseases such as rabies.

EHV-1 infection is easily spread to other horses by nose-to-nose or close contact with an infected horse, by sharing contaminated equipment including bits, buckets and towels or by the clothing and hands of people who have recently had contact with an infected horse. It is important, therefore, to restrict movement for 21 days of both people and horses where EHV-1 has been diagnosed. Any person leaving a facility to care for or be in contact with horses elsewhere should change their clothes, shoes/boots and wash their hands before leaving the property. Facility owners should also inform all service providers that have attended the facility within the previous week, including, but not restricted to, veterinarians, farriers, feed suppliers and transporters, of the presence of the virus at the facility so they can take appropriate precautions.

Biosecurity is key to preventing spread of EHV-1. Implementing routine biosecurity measures is the best way to minimize viral spread and should be in place at all times to prevent a disease outbreak. Such measures include hand hygiene and basic cleaning and disinfection practices. Horses that have been shipped long distances should be segregated for 14 days prior to entering the general population.

EHV-1 vaccines marketed for prevention of respiratory disease may reduce viral shedding but are not protective against developing the neurological form of the disease in the vaccinated animal.

For additional information:

► OMAFRA - Preventing Disease Spread - Personal Hygiene and Disinfectants around Horse Barns

► OMAFRA - Horses - Health Management and Biosecurity

► CFIA - National Farm and Facility Level Biosecurity Standard for the Equine Sector

(with files from OMAFRA)