Dr. Maro: Rabbit owners be wary of risks of RHDV2
Many of the articles I write deal with pet dogs and cats, but I also care for many other species of companion animals, including pet rabbits.
Pet rabbits need checkups, monitoring of their dental health, skin, coat, nutrition and nail care. In August, a relatively new disease in rabbits was identified in a domestic rabbit facility in Fayette County. Recent developments and the progression of this infectious disease, known as RHDV-2, have caused concern for owners of lagomorphs (bunnies).
Owners of pet rabbits have been told for years that no vaccines are needed for their fluffy companions, but recently that has changed with the development of a vaccine for a disease called RHVD2, or Rabbit Hemorrhagic Disease Virus Type 2.
RHVD2 is caused by a virus in the family of viruses known as pathogenic calicivirus. This new strain of RHVD was first found in 2010 in France. In 2018, the virus was found in rabbits in Ohio. Another case was detected in 2018 in Washington state. As of 2020, the virus, which is often fatal before any signs are evident, had spread across the southwest USA and Mexico.
The highly contagious (between rabbits) virus affects the liver, causing the liver cells called hepatocytes to die off rapidly. This can lead to a condition called DIC (disseminated intravascular coagulation), which causes the body to use up clotting factors leading to massive internal hemorrhage. Hepatic encephalopathy (brain effects from the buildup of toxins in the blood) can also occur. Another effect is nephrosis, which means that the kidneys can also become affected by the RHVD2.
Signs of the virus are usually not noted, as the rabbits die quickly from the condition. Once rabbits are infected, there is no known cure. Controlling the virus is tricky because people can carry the virus, unknowingly, on their shoes and clothing if they have walked in an area where blood, excretions, carcasses, or food or water of an infected rabbit have been, even long after a rabbit has died. Owners who walk through areas where wild infected rabbits have been can carry an active virus on their shoes; if a wild rabbit died as a result of the virus, the area where it died and decomposed can have viral organisms remain infectious through heat and freezing conditions for as long as 3-4 months.
Products like Clorox household wipes DO NOT kill or inactivate the virus. Disinfection requires the use of 10% bleach solution (this is a really strong solution) and at least 10 minutes of contact time before rinsing. Disinfection also requires that the area be totally cleaned of all organic material and remains of animals that have died from the virus.
Mortality rates are between 70-100%. This means that for every 10 rabbits infected 7-10 of them will die — that is, if they have not been vaccinated. The vaccine appears to be providing good immune protection. I have been vaccinating pet rabbits this year and thus far, have not seen any reactions in vaccinated bunnies and none of the vaccinated pets have contracted the viruses.
In rabbits that do not die rapidly, RHDV2 symptoms are serious and include fever, lethargy, internal bleeding, loss of appetite, breathing difficulty, blue-tinged gums and organ failure. RT-qPCR and ELISA tests are commonly used tests to identify the virus in affected rabbits. Post-death or postmortem samples of the liver can also be used to ID the virus.
Vaccinating rabbits as early as 30 days of age helps prevent infection. Most owners don’t purchase or adopt their bunnies until they are 8 weeks of age, so seeing a vet, soon after adoption, who cares for rabbits and carries the RHDV2 vaccine is important. If you have a pet rabbit, be sure not to introduce any new rabbits into your home, without having a long quarantine period. If a pet rabbit dies, have your veterinarian evaluate your pet’s body for the cause of death, and be certain to follow your vet’s advice for disinfection and waiting periods before introducing new rabbits to your home.
Fortunately, humans are not affected by this virus; while there is no risk to humans who own rabbits, both domesticated and wild rabbits are at risk.
The bottom line is:
If your pet shows any sign of illness, go to a vet who sees rabbits regularly.
Get your rabbits vaccinated, twice in the first year and then annually after that.
When introducing new rabbits, have a quarantine period of 30 days, in order to get new bunnies vaccinated and boostered before introducing newcomers into your herd or colony.
Rabbit owners can find lots of great information about rabbit care at: www.rabbit.org
Dr. Cynthia Maro is a veterinarian at the Ellwood Animal Hospital in Ellwood City and the Chippewa Animal Hospital in Chippewa Township. She writes a biweekly column on pet care and health issues. If you have a topic you’d like to have addressed, email ellwoodvet@msn.com.
This article originally appeared on Beaver County Times: Maro: Rabbit owners be wary of risks of RHDV2
