Hemorrhagic rabbit disease found in California

A deadly virus is threatening to wipe out entire populations across multiple states. At risk are North America's rabbits.

It's a strain of Rabbit Hemorrhagic Disease, and it's recently appeared in pockets of the Western US. If it continues to spread unchecked, it could harm all dozen-plus species of rabbits in the US and the ecosystems they belong to.

The highly contagious illness isn't connected to coronavirus -- only rabbits, hares and pikas, the diminutive cousin of rabbits, can spread it among each other, and humans can't become infected with it.

Rabbit Hemorrhagic Disease virus type 2 can cause internal bleeding and swelling, but more often, the sickened rabbits aren't discovered until they've already died, according to the California Department of Fish and Wildlife.

There are some parallels between Rabbit Hemorrhagic Disease and Covid-19, said Matt Gompper, a disease ecologist and head of the Department of Fish, Wildlife and Conservation Ecology at New Mexico State University.

Both are thought to have "spilled over" from one species to another -- in the case of the novel coronavirus, likely a bat to humans; in the rabbit disease, from domestic to wild rabbits -- and both arose so quickly that health officials had a limited window to act.

How the disease came to the US

The disease likely originated around a decade ago in European rabbits, which comprise most domestic rabbits sold in the US, Gompper said.

Then, in early March, another strain of the virus was discovered in wild rabbits in southern New Mexico. A few days later, dead rabbits were spotted nearby in El Paso, Texas. More sightings followed in Arizona, Colorado and, in May, in California.