Highly contagious disease confirmed in pet rabbit

Two Ramsey County indoor rabbits died suddenly and inexplicably earlier this month from a highly contagious rabbit disease detected for the first time in Minnesota. When the second rabbit died shortly after the first, the owner, a veterinarian, submitted it to the University of Minnesota Veterinary Diagnostic Laboratory (VDL) to investigate the cause of death. The VDL described liver lesions and sent samples to the USDA’s National Veterinary Services Laboratories, which confirmed Rabbit Hemorrhagic Disease Virus 2 (RHDV2) last week. The owner reported the rabbits were indoor pets and had no contact with other rabbits. RHDV2 is a highly contagious virus affecting domestic and wild rabbits. There is no known risk to humans.

“The Board of Animal Health is investigating the cause of this RHDV2 case,” said Senior Veterinarian Dr. Greg Suskovic who oversees the Board’s Foreign Animal Disease Investigations. “Rabbit owners should contact their veterinarian if their pet dies unexpectedly or exhibits any of the signs consistent with RHDV2. Veterinarians should report suspected cases to the Board.”

Sudden mortality in otherwise healthy rabbits is characteristic of RHDV2. Infected rabbits may be lethargic and reluctant to move, and typically die between a day and a week after becoming infected. The virus kills 70 to 90 percent of infected rabbits. Rabbit carcasses may have bloody discharge from the nostrils and/or mouth or have no external signs. Unusually high mortality in wild rabbits should be reported to the Department of Natural Resources. No other species of wildlife are known to be susceptible.

RHDV2 is highly contagious and can spread through direct contact with infected rabbits or indirectly through contact with infected carcasses, blood, urine, and feces. The virus can also be present on contaminated clothing, footwear and surfaces such as cages, feed, water, and bedding. Insects, scavengers, predators, and birds can also spread the virus by contact with infected rabbits or carcasses. RHDV2 is very persistent and stable in the environment. It is resistant to extreme temperatures and can survive freezing. The virus has been found to survive up to 15 weeks in dry conditions. The USDA recommends using a high pH solution to inactivate RHDV2 when disinfecting surfaces.

There is not a RHDV2 vaccine approved for use in Minnesota. There are vaccines for this disease in Europe, which use inactivated virus derived from the livers of rabbits infected in a lab and are not approved for import into Minnesota. A private company in South Dakota is working on a recombinant technology vaccine for RHDV2, similar to the Pfizer and Moderna COVID-19 vaccines. The Board plans to discuss approval of this vaccine at its December 2021 quarterly Board meeting.

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