Rabbit Hemorrhagic Disease type 2, or RHD, is a highly contagious, lethal virus. Prior to the development of a vaccine, the disease was spreading across North America unchecked. Until then, the only way to combat this deadly disease had been with rigorous biosecurity protocols that were hard for the average rabbit owner to follow.
Easily spread and highly resilient, rabbit hemorrhagic disease causes lesions throughout internal organs and tissues, particularly the liver, lungs, and heart, resulting in bleeding. It is often fatal. Treatment is generally limited to supportive care, with infected rabbits kept in isolation. The virus does not infect humans or other pets. Rabbits that live or go outside are at much higher risk than strictly indoor bunnies, but you can track it inside to your bunny on your clothes or shoes.
Classified as a foreign animal disease, RHDV2 surfaced in the U.S. in 2018 and 2019 in a few isolated cases affecting domestic rabbits. When it was confirmed to be in wild cottontails and jackrabbits in several Southwest states in March and April 2020, officials and veterinarians who monitor the virus predicted it would eventually become endemic in North America, just as it has in Europe. Recently, the virus has been reported as close as Minnesota. The House Rabbit Society keeps a running list of cases and locations on its website.
The U.S. Department of Agriculture Center for Veterinary Biologics granted emergency-use authorization for an experimental vaccine in October 2021. It’s produced by Medgene Labs, a biotechnology company in Brookings, South Dakota. Since then, the vaccine has been cleared for distribution by animal health officials in 32 states, including Wisconsin.
The Medgene vaccine is administered as subcutaneous injections, with reported protection rates of 90% or better. The protocol is an initial vaccination followed by a second dose 21 days after the first. Full immunity is reached 14 days after the second dose. After the initial two doses, we will need to give annual boosters. The vaccine is safe for rabbits at or over 28 days old. It uses recombinant technology, similar to the Pfizer-BioNTech and Moderna COVID-19 vaccines.
The challenge we have with the U.S. product is packaging. The Medgene vaccine comes in 10- or 25-dose vials that must be used within hours of being opened, meaning we have to use up 10 or 25 vaccines at a time. This makes it impractical to vaccinate an occasional pet rabbit. (Medgene is aiming to provide single-dose vials but is hampered for the time being by supply-chain shortages.) We have been setting up rabbit vaccination clinics on Saturday mornings. We will send you a notice when we have a vaccine clinic set up.