Alberta EHV-1 Update

This posted today on the Moore Equine Veterinary Center site:

The Equine veterinarians in Alberta who are involved in the EHV-1 situation had a conference call today. To confirm, there is 1 confirmed case of EHV-1 in Alberta. Two horses that were in contact have been tested and are confirmed negative as of today (May 17th,2011), on both blood and nasal PCR testing.

A large group of equine veterinarians, provincial veterinarians and the Alberta Veterinary Medical Association had a conference call today regarding this issue. We reviewed the outstanding cases at this time and they are as follows:

• There is one confirmed neurologic case which showed neurologic signs on May 1, 2011 and was isolated at that time. This horse did not attend the Utah show but was in direct contact with the horses attending the above stated show before they left Canada. This horse has been under veterinary care and is recovering very well and is in no danger. The origin of the source of contact for this horse remains unknown.
• As of May 18, 2011 there is one yearling confirmed positive for EHV-1 which showed only respiratory signs of the disease similar to normal influenza infections. This horse was in direct contact with tack from the horses returning from Utah. This horse is under treatment and isolation and is in no danger as this time.
• As of May 18, 2011 there is an additional confirmed positive case of a horse returning from Utah which showed a mild transitory respiratory disease. This horse is under isolation and treatment and is in no danger.
• There are 6-8 tests pending on horses similar to the above horse, which have attended the Utah show and have experienced mild respiratory disease. We expect some of these horses to have a positive test and have taken this into account on our comments below.
• There are 3 confirmed cases in BC who attended the Utah show and have varying degrees of neurological disease but are all responding to treatment at this time.

Therefore, at this time, there have been no horses affected in the province of Alberta or BC that were not either at the Utah show or in direct contact with these horses, either before or after their return. The incubation period for this disease can be as long as 21 days but normally symptoms show within the first 10-14 days. Presently, we are within the 10-14 day timeframe.

Measures that have been taken:

• Competitions involving the horses directly affected by the Utah Show have been cancelled by the Cutting Horse Association until further notice.
• All of the participants attending the Utah show have been notified and asked to isolate their horses.
• The Chief Provincial Veterinarian is gathering all information, monitoring the disease and is looking into the epidemiology of EHV-1 in Alberta at this time.

Ongoing recommendations:

• All horse owners have been asked to carry out normal biosecurity protocols which can be found on many websites, including that of the Alberta Veterinary Medical Association.
• Any horse owner who has potentially been in contact with this group of horses should monitor the temperature of their horses twice daily for 14 -21 days post exposure and discuss any abnormalities with their veterinarian.
• The protection afforded by vaccination is debatable and we recommend that horse owners discuss it with their veterinarian, as every horse is unique and requires a different vaccination protocol.

It is the opinion of this group of veterinarians the risk associated with attending a competition or event is very low at this time. This is due to the fact, only one horse has been affected with the neurologic form in Alberta and currently there has been no \”second wave\” of infection. We will be monitoring this situation closely and will update this position if there is any significant change.

– Greg Andrews, DVM