Nearly 20 burros, or wild donkeys, that roam the foothills and canyons between Colton and Moreno Valley have died in recent weeks as an illness spreads among herds.
The culprit, experts said, is a viral equine influenza that started spreading among one or two herds in mid-June. Mostly young burros began showing signs of the infection, Inland Empire horse veterinarians and animal rescue officials said. Some donkeys were unvaccinated and died before they could receive care.
“The (equine) influenza is spread through air droplets, water, nose-to-nose respiration,” and can be prevented by vaccines, said Chad Cheatham, vice president of the non-profit rescue center DonkeyLand. in the Reche Canyon area.
Seventeen deaths have been reported in the area so far — most of them, 12, in the Moreno Valley area. But a doctor said the sickness cannot be spread to humans or other kinds of animals.
DonkeyLand, a volunteer-run sanctuary and rescue center for the animals, has been receiving frequent calls about sick or dying burros in Reche Canyon, between Colton and Moreno Valley, and the surrounding areas.
The wild donkeys are seen in natural areas including Reche Canyon and in the foothills along Box Springs Mountain, Pigeon Pass Road, Redlands Boulevard and San Timoteo Canyon Road. In late 2020, more than 40 burros died from an equine influenza in the same area.
Last week, two deceased wild burros were sent to a state lab in San Bernardino for testing, a DonkeyLand news release states. The preliminary findings were positive for equine influenza.
Brian Cronin, chief of San Bernardino County Animal Care, said by email that the illness is occurring primarily in Riverside County and Moreno Valley. Representatives from Riverside County Animal Services, which rehabilitates the animals, could not be reached Wednesday, July 6.
In San Bernardino County, burros have been identified in the Reche Canyon, San Timoteo Canyon and mountain communities and Parker Dam areas. Aside from illness such as the infection, they are sometimes injured, hit by cars or found deceased, Cronin said.
Moreno Valley Animal Services Director Steve Fries said there have been six reported donkey deaths in the area of Redlands Boulevard and Locust and Juniper avenues in the city. Lab results on two of the donkeys indicate they died from viral pneumonia with a secondary bacterial infection, Fries said.
“Wild donkeys are not vaccinated,” Fries said. “These donkeys are also social creatures, and they are often in close proximity to each other and share water resources, leading them to be in close contact with an infected donkey.”
Those who work with the donkeys don’t know if the same illness as 2020 is striking the animals, he said. Experts suggest that equine owners vaccinate their animals for equine influenza and consult veterinarians.
Dr. Paul Wan, a veterinarian with the SoCal Equine Hospital in Norco and Apple Valley, said symptoms in the burros are visibly noticeable. They include foaming bubbles in the mouth, runny noses or nasal discharge, coughing, heavy-labored breathing and lethargy.
“They use their stomach muscles to breathe, and you can see their flanks moving,” said Wan, who helps rehabilitate ailing burros at DonkeyLand. “It’s an aerosolized virus. This time, it’s affecting more of the younger burros, from newborns to 2- or 3-year-olds.”
Wan and the DonkeyLand staff set a goal to gather and vaccinate at least 20% of the area’s wild burros — approximately 250 to 300 — that are susceptible to viruses.
An equine herpes virus killed or sickened many domestic and show horses earlier this year. The outbreak temporarily shut down equestrian events in counties and cities statewide, including Norco in Riverside County.
Wan said the equine influenza infecting the burros is “species specific” — so it cannot be spread to humans or other animal species. Wan believes this current round is “the same strain” as the equine flu seen in 2020.
“I don’t think it’s mutated or anything. It’s just, unfortunately, we’re dealing with naive animals. They don’t have any immunity and they’re just susceptible,” Wan said. “It’s like if you’ve never been exposed to the flu, and then all of a sudden you’re exposed, and you’re probably gonna get it … unfortunately, the ones we vaccinated in 2020 probably don’t have a lot a whole of immunity.”
Cheatham said the virus is easily spread among herds, or sometimes through horses — or by the burros drinking any water not found naturally. Residents sometimes leave water outside for wild donkeys they think are dehydrated in the heat.
“People put water out and it could be very dangerous if it’s not cleaned or topped off with new water,” said Amber-LeVonne Cheatham, the founder of DonkeyLand. “There may be viruses getting passed, and it can cause fatalities. I know people love and want to save the burros, but it’s just dangerous.”
The wild burros are not dehydrated, Amber-LeVonne Cheatham said. They can find natural spring water from the mountains and surrounding foothills, she said.
An ordinance in Riverside County bars anyone from feeding wild burros.