An equine influenza outbreak has killed about three dozen wild burros in the inland region of Southern California and authorities expect the number to rise.
Horse owners are being urged to consult their veterinarians, get booster vaccines for previously vaccinated animals and move them away from fence lines in areas where wild burros frequent, Riverside County Animal Services said in a press release.
The deaths, which began in mid-October, have mostly occurred in the Reche Canyon area in the western foothills of the San Jacinto Mountains. About 500 burros live in the area 60 miles east of Los Angeles.
Equine influenza is a highly contagious virus specific to horses, mules and donkeys.
It spreads rapidly through aerosolized droplets created by coughing or by contamination of surfaces, Animal Services said.
Most symptoms are respiratory but there are others including fever. Clinical signs are more severe in younger horses as well as in donkeys and mules, while older horses usually have milder illness, the agency said.
Experts say the virus can be spread on equipment, brushes, water buckets, clothing and hands.
State veterinarian Alisha Olmstead said owners should avoid traveling with their horses if they believe they’ve been exposed, and visitors with horses should not come onto their properties.
Animal Services said the public should avoid contact with the burros.