Wildlife officials warn of deadly virus that 'spreads quickly' threatening wild, domestic rabbits

PALM SPRINGS, Calif. -- Wildlife officials are warning about a deadly virus that has killed wild and domestic rabbits in Arizona, California, Colorado, New Mexico, Texas and Mexico since March.

It's called "Rabbit Hemorrhagic Disease."

Confirmed cases in the U.S.

Officials with the California Department of Fish and Wildlife said lab testing in New York confirmed the presence of RHD virus type 2 (RHDV2) in a sample from a black-tailed jackrabbit carcass from private property in Palm Springs, California in early May -- the first such detection in the state. This was one of about 10 dead jackrabbits on the property, officials said.

In Arizona, officials reported a confirmed case of the virus in a domestic rabbit on March 25. Dead cottontails and jackrabbits had also been found in the area.

In Colorado, officials said the virus was confirmed April 17 in three wild cottontail rabbits approximately 10 miles southeast of Alamosa in Costilla County.

In New Mexico, wildlife officials said they collected carcasses for testing after reports of dead wild rabbits in early March. Arizona officials noted on April 2, New Mexico Game and Fish announced that RHDV2 had been detected in black-tailed jackrabbits and cottontails, representing the first detection of this virus in wild rabbits in the United States.

In Texas, animal health officials were notified of the presence of the virus in domestic rabbits on a Hockley County premises in April on April 10.

About the virus

RHDV2 is not related to the coroanvirus. It is a "calcivirus" that does not affect humans or domestic animals other than rabbits.

The disease is highly contagious and often lethal to both wild and domestic rabbits, and it has spread quickly in other states, wildlife officials noted.

Infected rabbits and jackrabbits may exhibit no symptoms leading up to their sudden death, or may suffer from fever, swelling, internal bleeding and liver necrosis. The range of susceptible species in North America is currently unknown, but all rabbit, jackrabbit, hare and pika species are likely susceptible.

It's transmitted between rabbits through contact with other infected rabbits or carcasses, their meat or their fur, contaminated food or water, materials coming into contact with them -- or people spreading the virus to new areas.

History of the virus

Officials with the United States Department of Agriculture said the first detection of RHDV2 in North America was on Delta and Vancouver Island, Canada in feral rabbits in February 2018. It was later confirmed in a pet rabbit in Ohio in September 2018.

In fall 2019, it was detected in a pet rabbit and feral rabbits on Orcas Island in San Juan County, Washington.

How you can help

Wildlife officials have asked that people report sightings of sick or dead wild rabbits, hares or pikas to contact wildlife officials or file an online mortality report so they can track the spread. They've also asked that people take precautions while hiking or camping, so as not to disturb carcasses -- and they've advised hunters to take precautions to minimize the spread, with rabbit hunting season set to open July 1 in California.

If it spreads, wildlife officials noted it has the potential to "cause significant declines of rabbit populations," including endangered species.

They've asked that domestic rabbit owners contact their veterinarian regarding a sick animal.

Officials said the virus is "hardy" and can remain viable on meat, fur, clothing and equipment "for a very long time."