Warning: this is a startling disease and a heavy topic. (There is a picture of some healthy bunnies at the end to lift some spirits.)
What is Rabbit Hemorrhagic Disease Virus?
Rabbit Hemorrhagic Disease Virus, or RHDV, is a virus (of the calicivirus family) that only infects rabbits. It is often fatal (some very young rabbits will survive) and there are not many treatments available. It causes clinical signs similar to the Ebola virus in humans, and has a similar fatality rate. It can be transmitted through direct contact, bedding, toys, hutches, or even through insects. Unfortunately the virus can survive in the environment for months, on top of the fact that it is very easily spread.
Rabbits are often asymptomatic for about 9 days after exposure. They are contagious at this time. Once they start to show clinical signs, they have a decreased appetite, crusting around the eyes and nose, fever, and possibly even more fearful behavior than usual. Within 36 hours of showing signs, they will succumb to the disease. The virus affects the liver, lungs, and heart, especially, which leads to bleeding out of the nose and mouth just prior to and after death. Treatment involves supportive care, and is rarely successful. Those that do survive are thought to be completely immune for life.
There are three subtypes of the disease (RHDVa, RHDV1, and RHDV2). They do vary in survival rates and rate of spread, but all are fatal in most cases. The only way to diagnose the disease currently is through tissue samples, often performed after the animal has passed away.
Alright, now I’m worried about my rabbit!
Good news: RHDV is not in Massachussetts (yet). It has only recently entered the United States and has only been found in the South-West portion of the country. There have been a few outbreaks in the U.S. in the past 10 years. It is spreading rapidly, however. Because our populations of wild and domestic rabbits have not seen this virus, they are very susceptible, allowing the virus to spread even more easily.
The best way to treat RHDV is to prevent it! Rabbits who live outdoors may need to be moved indoors to prevent contact with wild rabbits and with insects carrying the disease. Remember, rabbits are symptomatic for 9 days, but are contagious during this time. Do NOT pick up any rabbit carcasses in or around your property.
If you are planning to travel to an endemic country (Australia, England, etc.). consider removing all clothing and shoes before entering your house and washing all immediately. If you live in a state with positive cases (Colorado, Texas, California, New York, Arizona, New Mexico), consider removing your shoes prior to entering your house each day. Your rabbit can get it if you bring it in on soil on the bottom of your shoes.
If you have other pets (dogs, cats), consider keeping cats indoors and keeping dogs on leash. If a dog gets ahold of a sick/deceased rabbit, it can bring the disease into your home. Use flea and tick preventives on your cats, dogs, and even rabbits. Please contact a veterinarian to find out which flea and tick preventives are safe for your pets– not all flea and tick preventives are safe for rabbits. Also, consider purchasing your hay and other food products from a reputable source that is aware and mitigating risks of the disease.
There is a vaccine available in other countries, but none have been approved for use in the United States, yet. Many rescue groups are pushing for approval and manufacture in the United States, as they were recently approved in Canada. A few specific veterinarians in the U.S. have obtained a permit for purchasing and importing the vaccine, however, this is very costly and difficult to do.
If your rabbit is showing signs of RHDV, please contact a veterinarian immediately.
For more information and regular updates, please see: https://www.oxbowanimalhealth.com/blog/rhdv2/