Update on EHV-1 Conference Call

June 13th, 2011

An update on the EHV-1 situation in Alberta and Western Canada was obtained this morning via a conference call with Veterinarians from Alberta, British Columbia and Saskatchewan. Participants of the conference call included the Chief Provincial Veterinarian, members of Alberta Veterinary Medical Association, faculty from the University of Calgary Veterinary Medicine, Provincial Animal Laboratory veterinarians and local Equine practitioners.

There has been one new case of nEHV-1 reported since the last telephone conference call on June 8th, 2011.

To date the reported positive cases of nEHV-1 in Alberta are as follows (All reported in previous updates):

 One neurological case (now recovered) first found positive at the start of May

 Four cases positive, including the one newly reported case (We consider this a delayed testing scenario rather than a secondary spread of the disease). This new case and the 3 others are experiencing mild respiratory signs/fever and are all now recovered.

 Four PCR positive horses, showing no clinical signs

 One neurological case (responding well to treatment) that attended cutting events in Alberta

 One neurological case in Northern Alberta that was at the cutting competition in Lloydminster

To date suspect cases of nEHV-1 in Alberta are as follows (All reported in previous updates):

 One previously reported neurologic case. The mild neurological signs are almost resolved and the horse remains under quarantine. To date testing has been negative.

 The second suspect with mild neurological signs in Northern Alberta that was at the cutting competition in Lloydminster (reported in last update) remains in the suspect list.

 Neurological suspect case from Central Alberta was euthanized due in part to complications with previous, significant medical conditions. Testing remains pending.

 One suspect respiratory case is at the same premises as the new positive reported case (mentioned in the second bullet noted in the reported positive cases above.

The one confirmed and one suspect case both are from a cutting horse barn that had horses at the Ogden show.

No new cases have been reported by the Saskatchewan or British Columbia laboratories in attendance on the conference call. nEHV-1 cases are not required to be reported to the provincial government in these provinces therefore we have limited information on cases.

Releasing horses from quarantine:

It has come to the attention of the veterinarians that one of the horses that had mild respiratory signs and fever that initially tested positive for nEHV-1 was recently retested positive for nEHV-1 on nasal swabs prior to being released from the 21 days of quarantine. In light of the potential for prolonged shedding of the virus, it is now the recommendation of the veterinarians involved in the call, all horses that tested positive for nEHV-1 be retested (and confirmed negative) prior to release from quarantine regardless of the time spent in quarantine. This need for testing has been confirmed in the most recent conference call.

It appears that all of the cases and suspected cases remain in horses associated with the cutting horse industry. To address concerns for the upcoming cutting horse competitions, the group has created a list of recommendations for organizers of cutting horse competitions (see attached). All other disciplines outside of the cutting industry continue at this time to be considered low risk. The decision to cancel competitions and shows in other disciplines should be made in partnership with their associated veterinarian to develop a risk assessment of each situation. Biosecurity is a key component to limiting spread of any infectious disease and all individuals in contact with horses should remain mindful of appropriate procedures.

The next conference call is scheduled for Monday June 20th, 2011. If any local veterinarians would like to participate they can contact the office of the Chief Provincial Veterinarian for further information.

As always we will continue to update our information as it becomes available.

Greg Andrews, DVM, Moore Equine Veterinary Centre Ltd.

Ashley Whitehead, DVM, BSc, DVSc, University of Calgary