California Deer Face Their Own Deadly Virus — And Social Distancing Could Help

An outbreak of adenovirus hemorrhagic disease has hit deer in five California counties.

Deer in Northern California are dealing with a deadly viral outbreak of their own, and wildlife experts say the best way to help the animals is to discourage them from congregating in large numbers.

Adenovirus hemorrhagic disease, which is highly contagious among deer and hits fawns the hardest, has been found in Napa, Santa Clara, Sonoma, Tehama and Yolo counties, The Sacramento Bee reported. The illness isn’t known to affect people or pets but can be devastating for deer populations.

Symptoms include drooling, foaming at the mouth, vomiting, diarrhea and seizures. However, there may not be obvious signs that a dead deer was infected with the virus. Officials are asking Californians who see symptomatic deer, or deer dead from unknown causes, to report the sightings online to the state’s Department of Fish and Wildlife.

The virus is transmitted by direct contact between deer and through bodily fluids. It’s also possible that it’s transmitted through airborne routes, according to the Oregon Department of Fish and Wildlife. There’s no cure or vaccine.

Wildlife officials in California are warning of a viral outbreak among deer in the northern part of the state that's especial
Wildlife officials in California are warning of a viral outbreak among deer in the northern part of the state that's especially deadly to fawns.

To help curb the spread of the disease, officials have asked people to secure their garbage and not leave food out for deer, which can encourage large numbers of deer to gather in one place, thus fueling the spread. It’s actually already illegal in California to feed deer, but wildlife professionals are emphasizing it’s particularly important not to do so now.

“Providing attractants for deer ― food, salt licks or even water ― is against the law for good reason,” Dr. Brandon Munk, senior wildlife veterinarian with the California Department of Fish and Wildlife, said in a news release. “Because these artificial attractants can congregate animals and promote the spread of disease, it’s particularly imperative to leave wildlife alone during an outbreak.”

Alison Hermance, spokesperson for wildlife rehabilitation center WildCare, couldn’t help but notice the similarities to the advice humans are getting about COVID-19.

“They need to stay socially distanced apart from each other so they don’t spread the virus between them,” she told CBS San Francisco. “It’s a really interesting parallel with what’s happening with humans.”

Thousands of deer died of adenovirus hemorrhagic disease during a major outbreak in California in the early 1990s that spread across 18 counties.