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Connecticut

Hunting

Rabbit Hemorrhagic Disease Poses Threat to Wild Rabbits

Paul J. Fusco/CT DEEP Wildlife Division

Scientists believe that all rabbits and hares are susceptible, including the New England cottontail, eastern cottontail, and snowshoe hare.

Rabbit hemorrhagic disease is a fatal disease in rabbits and is considered a foreign animal disease in the United States. This disease is caused by several virus strains. Animal health officials detected one of these strains, Rabbit Hemorrhagic Disease Virus Serotype 2 or RHDV2, in North America in the past few years. RHDV2 is highly contagious and, unlike other rabbit hemorrhagic disease viruses, it affects both domestic and wild rabbits, including hares, jackrabbits, and cottontails. The New England cottontail, eastern cottontail, and snowshoe hare, which are found in Connecticut, are susceptible to infection and mortality. At this time, RHDV2 is not known to impact humans or other animals.

So far, RHDV2 has appeared in nine U.S. states: Ohio, Washington, Texas, New Mexico, Arizona, Colorado, Nevada, California, and an isolated case in domestic rabbits in New York City. Natural resource agencies have reported events in which three to more than 1,000 rabbits and hares have died. The outbreak in the southwestern U.S. is linked to a different strain than the outbreak in the Pacific Northwest and New York, suggesting at least two separate introductions of the virus. RHDV2 has also infected pet rabbits and feral rabbits (domestic rabbits that have been released or escaped from captivity and now live in the wild).

Transmission

The RHDV2 virus is very resistant to extreme temperatures, and can stay viable for months. Rabbits can get the virus from contaminated food and water, contact with infected rabbits, and contact with feces of predators or scavengers that have eaten infected rabbits. People can spread the virus indirectly by carrying it on their clothing and shoes. The first sign of infection is often the sudden and unexpected death of a previously healthy rabbit.

People can inadvertently spread RHDV2 into the wild by releasing domestic or unwanted pet rabbits or through improper disposal of dead rabbits.

Symptoms of RHDV2

Many times, the only signs of the disease are sudden death and blood-stained noses caused by internal bleeding. Infected rabbits may also develop a fever, be hesitant to eat, or show respiratory or nervous system signs, such as poor balance or involuntary movements.

Is RHDV2 a Conservation Concern?

Scientists believe that all rabbits and hares are susceptible, including the eastern cottontail, snowshoe hare, and our only native rabbit, the New England cottontail.

While RHDV2 has not been confirmed in wild rabbits in eastern North America, biologists and other experts are very concerned. The disease spreads quickly and easily in the wild and could easily wipe out species with small populations, such as the New England cottontail. Rabbits play an important role in our ecosystem. They help control herbaceous vegetation and are an important part of the food chain for many predators, such as bobcats.

What Is the Wildlife Division Doing to Safeguard New England Cottontails?

The New England cottontail is found in parts of Maine, New Hampshire, Massachusetts, Connecticut, Rhode Island, and New York east of the Hudson River. An estimated 13,000 of these secretive animals exist today. The species’ population has decreased dramatically because its young forest and shrubland habitat is declining. Cooperative efforts between the Connecticut Wildlife Division, U.S. Fish and Wildlife Service, Natural Resources Conservation Service (NRCS), Wildlife Management Institute, other state wildlife agencies, and non-governmental organizations have resulted in habitat restoration, outreach and education, and monitoring and assessment of New England cottontail populations. To help stabilize declining populations and initiate recovery, state fish and wildlife agencies, private landowners, and other conservation partners have worked hard to enhance and protect thousands of acres of young forest and shrubland habitat critical to this rabbit’s survival. When animals have abundant habitat that supplies ample food and hiding cover, they will be healthier and less susceptible to diseases.

The Wildlife Division has been working closely with the U.S. Department of Agriculture, the State Veterinarian’s office, and the Northeast Wildlife Disease Cooperative to develop monitoring and testing protocols and increase awareness about this very serious disease. The Division is also working closely with other states across the country to monitor the spread of the disease and develop ways to prevent it from impacting new areas.

How Can You Protect Wild Rabbits?

Never release domestic or pet rabbits or hares into the wild since they may spread RHDV2, even if they seem healthy. In their early stages, many diseases, including RHDV2, are difficult or impossible to detect visually. (Released pets may also compete with rabbits, hares, and other animals by using food and other resources that wildlife depend on.)

If you own a domestic rabbit and it becomes ill or dies suddenly, contact your veterinarian or the Connecticut Department of Agriculture’s State Veterinarian. After handling such a rabbit, wash your clothes in hot water and detergent and disinfect all contact surfaces. Hunters and trappers should avoid taking rabbits that appear sick. Wear disposable gloves when handling game, double-bag carcasses and other remains and put them in the trash, and thoroughly clean knives and other equipment.

If you see a healthy rabbit suddenly die or find several dead rabbits in the same area, contact the DEEP Wildlife Division at 860-424-3011 or deep.wildlife@ct.gov.

To help stabilize declining populations and initiate recovery, state fish and wildlife agencies, private landowners, and other conservation partners have worked hard to enhance and protect thousands of acres of young forest and shrubland habitat critical to the New England cottontail’s survival.