Viral Haemorrhagic Disease (VHD) of Rabbits
VHD (viral haemorrhagic disease) is a highly contagious and acute fatal disease of rabbits. The virus is spread by direct and indirect transmission. The virus is very stable in the environment. The incubation period is 1 to 3 days and death usually occurs 12 to 36 hours after the onset of fever. VHD has been seen in Portsmouth. Vaccination is the only effective method of control.
The virus is very stable in the environment. It survives at least 225 days at 4°C, and 105 days at room temperature. It is also stable during freeze-thaw cycles. The major means of transmission is via insects and birds which are a significant source of infection.
The incubation period is short and death occurs 12 to 36 hours afterwards. There are many clinical signs such as high temperature, anorexia, lethargy and dullness, convulsions, incoordination, paralysis, groaning, breathing problems and bloodstained discharge from the nose. Numerous signs can be present together. The acute form of the disease usually presents with sudden death. In more unusual cases (about 5-10%), a chronic condition can occur with severe jaundice and weight loss. These rabbits usually die 1 to 2 weeks later.
There are many methods of testing for VHD, but the most accurate method is by post mortem examination, since death usually ensues quickly.
A highly effective vaccine is available from veterinary surgeons, and this offers the only means of protection against this deadly disease.
What this all means
VHD spreads very easily. It can cover long distances and some outbreaks can be separated by hundreds of miles. Initially the disease was notifiable in the UK, but now no such monitoring exists so the full extent of the problem is unknown.
Initially attempts were made to try to contain the disease, but this became impossible and an endemic state occurred. The persistence of the virus and the incidence of disease caused by it seem to be greatly underestimated. Because rabbits die so quickly from it they are often not presented to vets as they are already dead.
Vaccination gives one full year's immunity.