'Highly Virulent' Rabbit Hemorrhagic Disease has State Wildlife and Agriculture Agencies Scrambling
A deadly and highly virulent disease that devastated rabbit populations in some countries is now in the United States -- mainly the West, plus Florida. It is known to be an efficient killer - wiping out up to 80% of local rabbit populations. Many state wildlife agencies and consumer agriculture/veterinary agencies are working to prevent its spread. Virginia is one. Here is how wildlife managers are stepping up.
Rabbit Hemorrhagic Disease Virus Serotype 2 is an incredibly virulent disease that has impacted rabbits in 40 countries. According to the House Rabbit Society’s website rabbit.org, RHDV was first seen in China in 1984 but was thought to have originated in Europe. There have been confirmed cases in 40 countries, including in Europe, the Mediterranean, Africa, Asia, North America (Mexico, United States, Canada), Australia, and New Zealand. It has been documented in 12 western states and Florida. The U.S. Department of Agriculture also noted an apparent, single isolated case in a domestic New York rabbit.
Interestingly, according to a National Institute of health publication, the rabbit hemorrhagic disease virus (RHDV) was widely used in Australia and New Zealand since the mid-1990s to control wild rabbits, which were considered an “invasive vertebrate pest in these countries.” As viruses like to do, though, the original disease began changing. In January 2014, (again, according to the NIH document) an exotic RHDV (the version 2) was detected in Australia, and 8 additional outbreaks were reported in both domestic and wild rabbits in the 15 months following its detection.
The issue has been on the Virginia Department of Wildlife Resources radar since last year. The State of Michigan Department of Natural Resources has also released official guidance and fact sheets.
Marc Puckett, DWR’s small game project leader and Dr. Megan Kirchgessner, DWR’s wildlife veterinarian, gave me the lowdown on the disease and the agency’s efforts to keep it out of Virginia. Here is the synopsis:
This variant of the virus spread across Australia in 18 months. It arrived in the southwestern United States in April 2020 and has spread now as far east as central Texas and is in Colorado right on the western Kansas border. So far it appears to be spreading more slowly in the USA than in Australia.
When many Virginia hunters hear of “hemorrhagic disease,” they may think of the disease common to white-tailed deer, but the rabbit version of the illness is not like EHD or Blue Tongue in deer at all. Those diseases are transmitted only by the bite of a midge fly and EHD is not transmissible from deer to deer. The RHDV2 virus is spread in about every way imaginable – through direct contact with an infected live or dead rabbit or via contact with vegetation, soil, bedding, etc. that is contaminated with the virus. The virus persists in the environment for many weeks on a carcass and just a small viral load is required to infect a rabbit. It can race through a rabbit population, killing up to 80%.
Fortunately, the experts said, the disease is “not a zoonosis – meaning it is not transmissible to humans.” The only species affected are “lagomorphs – all rabbits, hares and pikas.” In Virginia this would include eastern cottontails, marsh rabbits and Appalachian cottontails and perhaps a very few remnant snowshoe hares in our highest northwestern mountains.”
Other animal species can help spread the virus when they move infected rabbit carcasses.
The Game Plan
The DWR formed a working group, led by Kirchgessner, more than a year ago to address the disease. The group developed a series of outreach fliers and provided information to rabbit field trial clubs and many rabbit Facebook sites. A broader fact sheet highlights the threat for both rabbit hunters and rabbit owners.
The agency’s small game committee proposed the new and changed regulations being considered this spring. The aim is to limit the movement of live-caught wild rabbits to the county of capture; allow only fully dressed carcasses of rabbits killed out of state to enter Virginia, with non-edible remains disposed of in the state where harvested, following that state’s guidance; and requiring proper disposal of all non-edible parts of rabbits harvested in Virginia. This means buried two feet deep, or incinerated, or double-bagged and disposed of at a permitted landfill.
Rabbits may not capture the big game interest of deer or wild turkeys. Still, protecting small game species is critical to our outdoors experiences and to a healthy ecosystem. I know I love the opportunities I get to join in fun beagle and rabbit adventures.
Importantly, this disease does not discriminate between domestic and wild rabbits. People raising domestic rabbits need to learn how to minimize chances of this virus spreading. When it comes to wildlife diseases, the old, “An ounce of prevention is worth a pound of cure,” resonates true. Puckett and Kirchgessner urge hunters and domestic rabbit enthusiasts to do what they can to prevent the introduction of this disease into Virginia.
Virginia's risk reduction and response plan is in the final stages of preparation, Puckett said. The plan will provide DWR a framework to accomplish the following goals: minimize the risk of introduction of RHDV2 into Virginia, confirm RHDV2 in wild rabbit populations soon after its introduction, and minimize the geographic spread and reduce rate of transmission of RHDV2 post-introduction.
Releasing domestic rabbits into the wild is illegal (in Virginia anyway) and dangerous to wild populations. Don’t do it! Don’t move rabbits outside of their county of capture. Finally, stay vigilant for finding groups of rabbits (more than three) dead in a small area over a short period of time. Virginians can report findings to the nearest DWR regional office or to the Wildlife Helpline at 855/571-9003. Residents of other states should check with their state wildlife agency for similar reporting and prevention measures.