TEXAS PARKS and Wildlife Department (TPWD) has received test results confirming that Rabbit Hemorrhagic Disease (RHD) was diagnosed in a wild black-tailed jackrabbit in Lubbock County and a wild cottontail rabbit in Hudspeth County.
This marks the first confirmed cases of RHD in wild rabbits in Texas and follows the discovery of the disease in domestic rabbits in Hockley County. Since March 23, detections of the disease in both wild and domestic rabbits have occurred in New Mexico, Colorado, Arizona and Mexico.
There have been reports of mortality events both in wild cottontails (genus Sylvilagus) and jackrabbits (genus Lepus) in El Paso, Hudspeth, Brewster, Terrell, Lubbock and Pecos Counties in Texas.
Rabbit Hemorrhagic Disease (RHD) is a highly contagious viral disease that can affect both domestic and wild rabbit species. This disease is nearly always fatal and primarily affects adult rabbits.
The viral agent, Rabbit Hemorrhagic Disease Virus (RHDV), is a calicivirus, with two strains (RHDV-1 and RHDV-2) being reported in North America in recent years. RHDV-2 is known to affect wild rabbits and was determined to be the agent in the Lubbock and Hockley County cases. RHD is a Foreign Animal Disease (FAD), but has been detected in Canada, Washington and Ohio.
RHDV appears only to affect rabbit species (lagomorphs). It is not known to affect humans, livestock or pets other than rabbits. However, pets should not be allowed to consume dead animal carcasses.
“The loss of this prey species can affect big game populations as well as other populations like rodents due to a shift in what predators will go after,” said John Silovsky, TPWD Wildlife Division deputy director. “That’s especially true in fragile areas like the Trans Pecos.”
Often the only clinical sign is sudden death. In less acute cases, clinical signs may include the following: dullness/apathy, not eating, ocular and/or nasal hemorrhage and congestion of the conjunctiva. Some may develop neurological signs such as incoordination, excitement or seizure-like episodes. Infections in young rabbits are usually subclinical and deaths are rare.
This is a highly contagious disease that spreads between rabbits through contact with infected rabbits or carcasses, their meat or their fur, contaminated food or water, or materials that come in contact with them. RHDV2 can persist in the environment for a very long time. These factors make disease control efforts extremely challenging once it is in the wild rabbit populations.
“Texas Parks and Wildlife Department (TPWD) will be monitoring wild rabbit populations to determine the extent of the disease,” said Dr. Bob Dittmar, TPWD wildlife veterinarian. “We are continuing to receive reports of dead rabbits from the western part of the state. People can contact their local TPWD wildlife biologist if they notice sick or dead rabbits.
“We want to reassure everyone this disease does not affect people or pets,” Dr. Dittmar said. “TPWD will work with TAHC to keep the public informed as we learn more about the extent and severity of the disease.”
Domestic rabbit owners who have questions about RHDV2 or observe sudden death in their rabbits should contact their private veterinarian. Private veterinarians are requested to contact the USDA-APHIS or the TAHC at 1-800-550-8242, to report any suspected cases. Report all unusual mass morbidity (sickness) or mortality (death) events to the TAHC.
You can find more information on RHD in the USDA Animal and Plant Health Inspection Service.
—TF&G Staff Report