Deer disease in five counties leads to warning

A rare, virulent disease that is sickening and killing deer in five Northern California counties has prompted the state Department of Fish and Wildlife to ask residents for help by reporting potential cases and stopping providing food and water for the animals.

The outbreak of adenovirus hemorrhagic disease, which has no cure or vaccine, has been reported in Santa Clara, Sonoma, Napa, Tehama and Yolo counties. The disease is highly contagious among deer, but is not a danger to humans, pets or domestic cattle.

To help reduce its spread, residents should not feed deer, which can lead them to congregate in larger numbers.

“Providing attractants for deer — food, salt licks or even water — is against the law for good reason,” said Brandon Munk, senior wildlife veterinarian with CDFW’s Wildlife Investigations Laboratory. “Because these artificial attractants can congregate animals and promote the spread of disease, it’s particularly imperative to leave wildlife alone during an outbreak.”

The first cases of the disease were noted in May when the CDFW began receiving reports of deaths among free-range deer and at fawn rehabilitation facilities. Working with wildlife rehab organizations and the California Animal Health and Food Safety Laboratory, officials confirmed the disease as cervid adenovirus 1 (CdAdV-1), a rare but persistent illness that causes painful sores and swelling in the gastrointestinal tract, leading to internal bleeding and organ failure.

The last serious outbreak of this hemorrhagic disease was reported in 199394 among black-tailed and mule deer. At least 18 counties reported the disease. Since then, it has been identified as the cause of sporadic but often widespread outbreaks in California and other Western states.

Fawns are at greatest risk and have the highest rates of death. Yearlings and adult deer are more resistant, but deaths occur in these age groups as well, officials said. Outbreaks can be widespread and have significant impact on affected deer populations.

Deer infected with the disease are often found dead without any obvious symptoms and near water. Sick deer may show signs of drooling or foaming at the mouth, diarrhea, regurgitation or seizures.

In addition to removing food and other attractants, Californians can help wildlife veterinarians track and study the disease by reporting sightings of sick or dead deer, Munk said, even in areas where the disease has not been reported.

Anyone who sees a deer exhibiting symptoms, or who has encountered a deer that has died from unknown causes, should submit information to CDFW through the department’s online mortality reporting system, https://bayareane. ws/MortalityReporting.