Rabbit Hemorrhagic Disease
In 2020, Rabbit Hemorrhagic Disease Virus 2 (RHDV2), a virus that causes the notifiable foreign animal disease, Rabbit Hemorrhagic Disease (RHD), was detected for the first time in wild hares and rabbits in the United States. In August 2022, RHDV2 was detected for the first time in Pennsylvania in a domestic rabbit facility in Fayette County. RHD poses a threat to the commonwealth's cottontail rabbit and snowshoe hare populations, and as such, the Pennsylvania Game Commission is taking proactive measures to mitigate that threat. In September 2022, the Game Commission established Pennsylvania's first RHD – Disease Management Area (DMA) that covered roughly a 5-mile radius around where RHD was detected in a domestic rabbit facility. After no additional cases of RHDV2 were identified for 12 consecutive months, RHD-DMA#1 was dissolved in September 2023.
RHD Management Plan
The Game Commission endeavors to protect the commonwealth's cottontail and snowshoe hare populations, as well as the habitats they call home. In April 2022, the Board of Game Commissioners voted to adopt a disease management plan that outlines actions that will reduce the likelihood of RHD reaching Pennsylvania as well as guide agency decisions related to RHD in the commonwealth. This
plan was last updated in August 2022.
What is RHD?
RHD is a foreign animal disease, meaning it is not typically found in the United States and is of high concern to domestic and wild animal health. RHDV2 is one of two viruses that can cause RHD; it is a highly pathogenic and contagious calicivirus affecting hares, rabbits, and closely related species. RHDV2 was first identified in domestic rabbits in France in 2010 and since then, it has been responsible for mass die-offs in wild hare and rabbit populations in several countries including the United States. As of August 2023, RHDV2 has been designated by the USDA as stable-endemic to wild lagomorph populations in Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah, and Wyoming.
How does RHDV2 spread?
The virus is extremely hardy and highly contagious. It can spread between hares and rabbits via many pathways that include direct contact with infected live or dead individuals; ingestion of contaminated food or water; inhalation; contact with contaminated equipment, tools, and enclosures; viral movement by flies, birds, biting insects, predators, scavengers, and humans; and contact with urine, feces, and respiratory discharges from infected individuals. The virus can survive on clothing, shoes, plant material, or other items that could accidentally be moved from an infected area.
How does RHD affect hares and rabbits and what can we look for?
There is no specific treatment for the disease, and it is often fatal (generally 75%-100%) with the potential to result in large, localized mortality events. Hares or rabbits that do not immediately die following infection may present with poor appetites, lethargy, and blood coming from their mouths or noses.
Is RHD a public health concern?
RHD is not infectious to people or domestic animals other than hares or rabbits. However, multiple dead or sick hares or rabbits can also be a sign of tularemia or plague, diseases that can cause serious illness in people. Therefore, it is important that the public does not handle or consume wildlife that is sick or has died from unknown causes. It is also important to prevent pets from contacting or consuming wildlife carcasses.
Where exactly has RHDV2 been detected in wild hares and rabbits?
The United States Department of Agriculture's Animal and Plant Health Inspection Service maintains an RHD map at the following URL: https://www.aphis.usda.gov/aphis/maps/animal-health/rhd.
The University of Georgia's Rabbit Hemorrhagic Disease Awareness Team maintains a time-lapse map documenting the spread of RHDV2 across the United States. The website is managed by the RHD Awareness Team which is comprised of faculty from the Georgia Warnell School of Forestry & Natural Resources, the University of Georgia College of Veterinary Medicine, and the Southeastern Cooperative Wildlife Disease Study. The map can be accessed at the following URL:
- Early detection and removal of suspect carcasses will be Pennsylvania's best defense to mitigate any RHD outbreaks. We encourage members of the public to report any lagomorph mortality events (two or more dead hares or rabbits at the same location) to the Game Commission using the agency's Wildlife Health Survey or by calling 1-833-PGC-WILD or 1-833-PGC-HUNT. The public should avoid touching any dead hares or rabbits.
- Once established, RHD can quickly spread amongst wild rabbit and hare populations. The main risk of the disease being introduced to the commonwealth is through the importation of infected rabbits or hares, their products, or contaminated materials.
- RHD is also a threat to domestic rabbits. The Pennsylvania Department of Agriculture is the regulatory authority over domestic animals in the commonwealth and they inspect rabbit slaughter facilities. Such breeding and processing facilities may additionally consent to USDA and/or FDA oversight but such consent is entirely voluntary. In addition to PDA, USDA, and FDA, private veterinary practices can also provide animal health expertise for domestic or pet rabbits. Any questions regarding disease surveillance in domestic rabbit or hare species should be directed to these entities.
- Veterinary diagnostic laboratories are aware of RHD and any detections of RHDV2 in domestic lagomorphs in PA will be reported to the Game Commission.
- Clean and disinfect (after thoroughly cleaning, disinfect with a 1:10 solution of household bleach to water, soaking for at least 10 minutes) all surfaces and equipment that may have contacted suspected RHD-positive hares or rabbits. These precautions are incredibly important as the disease can be easily transmitted amongst and between wild and domestic populations.
- If instructed to dispose of carcasses, either incinerate or bury them deep enough to prevent scavenging (> 2 ft). Carcasses can also be disposed of in the commercial trash. When handling any carcass, always wear gloves and double bag the carcass.
- The virus is resilient and may remain on the landscape for weeks or months.
Executive Order - Importation Ban
In March of 2022, the Game Commission issued an updated Executive Order prohibiting the importation into Pennsylvania of any wild lagomorph – meaning rabbit or hare – or any of their parts or products, including meat, pelts, hides and carcasses, from any state, province, territory or country where RHDV2 has been detected in wild or captive lagomorph populations in the 12 months prior to the importation or where RHDV2 has been declared endemic in domestic or wild lagomorph populations. As of August 2023, RHDV2 is endemic to wild lagomorphs in 11 states
(Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah, and Wyoming). Hunters should contact the appropriate agriculture and wildlife authorities in non-endemic areas to determine if RHDV2 has been detected in wild or captive lagomorph populations in the previous 12 months.
This list is updated quarterly. For the most up-to-date list of states, please contact firstname.lastname@example.org.
History of RHD-DMA 1
In September 2022, RHD-DMA 1 was established by Executive Order following the detection of RHDV2 in a captive rabbit facility in Fayette County, Pennsylvania the previous month. After 12 months elapsed with no additional RHDV2 detections within the DMA, a follow-up Executive Order was issued in September 2023 rescinding the original Executive Order, thereby dissolving RHD-DMA 1. This was in accordance with the agency's Rabbit Hemorrhagic Disease Management Plan.