Thursday, October 10, 2019

Deadly deer virus detected in Western Washington yak

Chris McGann

The state animal disease lab confirmed a case of EHD in a
 Whatcom County yak this week.
Last week, a Whatcom County veterinarian  euthanized a six-year-old yak cow showing symptoms of Epizootic Hemorrhagic disease (EHD), a potentially deadly virus that primarily effects wild deer populations, but occasionally crosses over to cattle.

A subsequent Washington Animal Disease Diagnostic Laboratory (WADDL) necropsy confirmed the animal had EHD.

Two other yaks from the herd died in recent weeks after displaying similar clinical signs such as stiff gate, drooling and nasal secretions that are consistent with EHD.

According to the owner's report, the euthanized yak began showing signs of illness on Sept. 30.  It appeared to isolate itself from the herd, developed a thick-mucous runny nose, and had difficulty moving. The owner also observed small droplets of blood coming from possible fly bites near its eyes. They called the vet.

The clinical signs of EHD are similar to the much more devastating foot-and-mouth disease, so it is important to report suspected cases to the State Veterinarian.

EHD is not a threat to human health.

The the owners took the euthanized animal to WADDL in Pullman, where lab reports confirmed the EHD diagnosis.

The outbreak in Western Washington comes on the heels of a confirmed EHD diagnosis in four cows from Franklin and Walla Walla counties.

Biting midges or Culicoides gnats, commonly known as “no-see-ums” are the main way the disease is spread. Female biting midges can ingest blood from infected animals and then feed on uninfected animals. These midges typically breed near mud, so EHD outbreaks often occur when cattle and other ruminants congregate in wet areas.

No vaccines are available for EHD, so controlling the midges by eliminating standing water from areas used by cows, applying insecticides around water areas to decrease the swarms, or using bug repellent on the cows is the best defense.

For more information visit WSDA’s Animal Services Division webpage.