Aujeszky's disease or 'mad itch' or pseudorabies (meaning 'false rabies') is an acute, highly fatal viral disease caused by a herpes virus (Su-HV1).Pigs are the natural reservoirs of the virus but other mammals including cows, sheep, goats, dogs, rats, cats etc., are susceptible to infection. Pseudorabies is seen most commonly in cats who live on or around farms.The name pseudorabies is due to the similarities between the "furious" form of rabies. The virus affects the nervous system and is typically acquired by ingestion of infected prey such as rats or uncooked pork. Cat to cat transmission doesn't seem to be a problem.The incubation period of pseudorabies is 3-6 days. Infection occurs after ingestion of the virus, entering the nerve fibres. The virus is almost always fatal in cats, when death occurring within two days.
Symptoms of pseudorabies can initially suggest the cat has been infected with the rabies virus. However, pseudorabies runs a much shorter course with symptoms developing within hours of exposure and death occurring within 48 hours after the onset of clinical signs.Intense itching of the head and neck, which leads to self mutilation as well as hypersalivation (excessive drooling) are the two most common symptoms of pseudorabies. Other symptoms may include:
- Behavioural changes such as restlessness and crying, other cats may become lethargic.
- Shortness of breath.
- Ataxia (unsteady gait).
- Muscle stiffness.
- Head pressing.
- Vestibular signs such as circling and head tilting.
- Diarrhea and vomiting are sometimes seen.
Diagnosis of pseudorabies is made by a complete physical examination, and obtaining a medical history, including possible exposure to pigs. Accompanying symptoms compared to other possible causes. Rabid cats display aggression, cats with pseudorabies don't. Pseudorabies causes intense itching which isn't seen in rabid cats.Routine bloodwork such as complete blood count and biochemical profile are usually nonspecific.The virus may be isolated from tissues collected at necropsy.If your cat does recover (and this is rare), diagnosis can be made by measuring antibodies to the virus.
Other than supportive care, there is no treatment for pseudorabies, once infected, it almost always kills, usually within 48 hours.
As there is no treatment, prevention is of key concern. No vaccine exists for the disease, therefore preventing cats roaming, particularly in high risk areas is of great importance. Never allow your cat to eat raw or undercooked pork.
There is a small chance that the infection can be passed from cat to humans, and precautions must be taken when handling any animal suspected of carrying the disease.