Rabbit plague – rhd or vhd (viral haemorrhagic disease of rabbits)

In the following article we will discuss rabbit plague – rhd or vhd (viral haemorrhagic disease of rabbits).

Clinical signs and occurrence

First, a sudden high mortality is observed. With prolonged disease development, rabbits may have a high temperature and a bloody nasal discharge may be observed.

The disease occurs in both breeding females and fattening rabbits. Mortality can be as high as 90 % with an incubation period of only 48 hours. Animals that recover are resistant for 6 months. In the external environment, the virus survives for a long time and is extremely resistant. It is not affected by frost or high temperatures above 30 °C. Viruses also form several strains. Sick rabbits shed the virus in all secretions, including urine and faeces.

Spread of the virus

Rabbit plague is easily spread by direct contact between animals; the virus can enter the rabbit’s body through the nasal mucosa or conjunctiva. Considerable resistance in the environment means that the plague is easily spread indirectly, through feed, water, bedding and utensils. Rabbit plague virus is spread directly by stinging insects. Flies that have come into contact with infectious material – faeces or dead rabbits – spread the virus mechanically on their bodies and in their digestive tracts; anything that such a fly has sat on or defecated on is infectious to other rabbits. The breeder can also be a mechanical vector.

Prevention

The only prevention is vaccination with Pestorin, Pestorin mormyx (combination vaccine), Nobyvac, Castorex, Morin. Consult your veterinarian for the most effective vaccination schedule. Vaccinations should be repeated regularly (e.g. every 4 months).

New form of rabbit plague RHDV2

It has been present in Europe since 2010 (first in France) and in the Czech Republic since 2017. Interestingly, unlike the classical plague, it can also affect rabbits in addition to rabbits. The incubation period is 3-6 days. The mortality rate is 60-100 %. It is quite different from classical plague and is therefore considered a distant serotype. The virus is very resistant in the environment. Like classical plague, it survives in freezing temperatures. It is spread by direct contact, water, feed and infected bedding. Blood-sucking insects are also involved in passive transmission. Rabbits of different ages can become infected.

Progress

The course of the disease may be peracute, acute, subacute or in rare cases chronic. The infection is usually peracute (sudden death without clinical signs). The incubation period for RHDV2 is 3-5 days. The acute course is characterised by the sudden onset of clinical signs such as anorexia, apathy, fever or nervous symptoms. Death usually occurs within 3 days of the onset of fever. The chronic course occurs in only a small percentage of infected animals (about 5-10%).

In contrast to classical plague infection, deaths of very young rabbits as early as 15 to 20 days of age are common after infection with RHDV2. The pathological findings are the same as for RHDV, with bleeding in the lungs, enlarged spleen and changes in the liver. Rabbits that survive the infection have long-term immunity to the virus. However, they may continue to shed the virus in their secretions and thus remain a source of infection.

Prevention

Due to the fact that the RHDV2 virus has different antigens compared to classical plague, a special vaccine is required for vaccination. The effect of the classical plague vaccine in preventing RHDV 2 is very limited. It is necessary to use the vaccine: Eravac, Nobivac, Pestorin RHDV2. Consult your veterinarian for appropriate treatment.