For questions/concerns about this disease in humans, please call your doctor or the Montana Department of Public Health and Human Services (DPHHS).
For questions about this disease/parasite in wildlife, please call the FWP Wildlife Health Lab at 406-577-7882.
Rabbit hemorrhagic Disease is a viral disease of lagomorphs (rabbits and hares). There are two primary genotypes of RHDV that have been detected in the United States: RHDV-1 and RHDV-2. While RHDV-1 primarily affects domestic rabbits, RHDV-2 affects wild, feral and domestic rabbits and hares.
The first detection of RHDV2 in the U.S. was in 2018 in a pet rabbit in Ohio. The first detection in wild rabbits and hares was in New Mexico in 2020. The disease has since spread to several states in both domestic and wild rabbits and hares. RHDV2 is considered stable/endemic in most of the western half of the United States.
The first detection in Montana was in feral rabbits and wild cottontails in Yellowstone County in 2021. As of August 2026, RHDV2 has been detected in several Montana counties, including Big Horn, Stillwater, Sweetgrass, Musselshell, Fallon, Silver Bow, Carbon, Cascade, Gallatin, Lewis and Clark, and Park Counties.
RHDV-2 affects domestic, feral and wild lagomorphs. Susceptible species in Montana the Black-tailed Jackrabbit, Desert Cottontail, Eastern Cottontail, Mountain Cottontail, Pygmy Rabbit, Snowshoe Hare, White-tailed Jackrabbit, and American Pika. The Black-tailed Jackrabbit and Pygmy Rabbit are species of concern in Montana.
RHDV-2 is highly contagious among lagomorphs and can spread by direct contact with infected rabbits or indirectly through contact with infected carcasses, blood, urine, and feces. The virus can also be spread on contaminated surfaces such as cages, feed, water, bedding, clothing, or shoes. Scavengers, predators, and birds can also move the virus around on the landscape by moving infectious lagomorph carcasses or carcass parts.
RHDV2 is very persistent in the environment and is resistant to extreme temperatures. The virus can survive up to 15 weeks in dry conditions and can survive freezing.
Sudden death is most common with RHDV2. Die-offs in wild rabbits can involve single, a few, or many rabbits. Dead rabbits often look normal; however, some may have bloody discharge coming from the nostrils and/or mouth. Rabbits are not often observed acting sick prior to death but may be lethargic or reluctant to move. The virus kills 70-90% of infected rabbits.
RHDV2 only affects Lagomorphs. Humans are not susceptible.
Cases involving multiple sick or dead rabbits in a location increase suspicion of RHDV2 or other infectious disease. Report sick/dead feral or wild rabbits, particularly in cases of multiple affected animals, to the FWP Wildlife Health Program (406-577-7880 or 406-577-7882) or to the local FWP office. FWP staff will note the location and determine whether the animal should be collected for RHDV-2 or other testing. If the carcass is not needed for testing, it should be safely and properly disposed to prevent further transmission to other lagomorphs. Keep in mind that although RHDV2 does not infect humans, rabbits can carry other diseases such as tularemia and plague that can pose a risk to human health, so direct contact should be avoided.
Take the following precautions when handling or disposing of carcasses.
A bleach-water solution (1/2 cup bleach in 1 gallon of water) with a contact time of 5 minutes is the best disinfectant if you need to decontaminate surfaces. Use caution as this solution is corrosive and can damage tools and clothing.
For questions regarding domestic rabbits, contact your veterinarian or the Montana Department of Livestock.
What can falconers do to help?
Raptors may be able to move RHDV2 to new locations after contacting infected rabbit carcasses or parts. Falconers should avoid contact between falcons and rabbit carcasses if possible.