An update on rabbit haemorrhagic disease virus (RHDV)
10 Jan 2023
The Department of Agriculture, Fisheries and Forestry have recently updated their website with up-to-date resources about rabbit haemorrhagic disease virus (RHDV, or Calicivirus).
The different genotypes which can cause disease in rabbits (RHDV1, RHDV1a variant and RHDV2) have been highlighted, along with mention of the Filavac VHD K C + V inactivated bivalent vaccine which was recently approved for emergency use in Australia and can provide protection against both the RHDV1 and RHDV2 strains of the disease. The Cylap vaccine is effective against RHDV1 but may only provide partial protection against the RHDV2 strain.
Rabbit haemorrhagic disease virus (RHDV) is a disease of European rabbits (Oryctolagus cuniculus) that typically causes rapidly fatal disease.
Three strains of RHDV are present in Australia: RHDV1, RHDV1a and RHDV2. The RHDV1 strain was first released in Australia in 1996 as a biocontrol measure against wild rabbits. Over time, its efficacy as a biocontrol measure has decreased. In response, in 2017 Australian state and territory governments released RHDV1a, a new naturally occurring variant of RHDV1, in March 2017.
RHDV2 is a new strain of the virus that was first reported in Europe in 2010 and then in Australia in 2015. This RHDV2 strain was not released in Australia by any government department and it is not known how the virus entered the country. RHDV2 can affect rabbits of all ages and is currently the strain causing the highest mortality in pet rabbits.
Both strains can cause acute liver damage, with death occurring as a result of liver necrosis and/or internal haemorrhages. It can be spread via:
- Direct contact with infected rabbits,
- Via fomites such as bodily fluids, faeces, equipment and clothing, or
- Via vectors such as flies
It has a short incubation period of between one to three days, and death can occur rapidly. Symptoms include high temperatures (>40°C), anorexia and lethargy. Jaundice may be observed in the eyes and on the ears.
All veterinarians who work with rabbits are encouraged to remind pet rabbit owners of the importance of protecting their rabbits with regular calicivirus vaccinations.
For more information, keep an eye on this resources page which is kept updated with the latest about RHDV.