This is a rare disease, which is why I have not heard of it until today. It is a very serious, almost always fatal, viral infection, which can kill a cat very quickly without the usual symptoms.
It would seem that the cats most likely to catch this disease would be farm cats because the disease is caught by contact with infected swine (pigs are the reservoir host) or by ingesting contaminated pork or infected rats. As far as I can tell, these are all the sorts of things that farm cat might be exposed to.
Symptoms, when they show, are fever, head pressing, vomiting, salivation, rapid breathing, depression, lethargy, convulsions and eventually coma. One symptom which is a little unusual is that this virus causes intense itching of the head and neck causing the cat to scratch in an excessive way causing injury. This should be a noticeable and distinct sign when added to the other symptoms.
Diagnosis is done through a complete physical examination and, of course, noting any exposure that the cat might have had with pigs.
The course of the disease is rapid: in 60% of cats the condition lasts from 1 to 1.5 days and is almost always fatal. Untypically, in 40% of cases the condition lasts for more than three days and once again is almost invariably fatal.
A well-known veterinary website says that there is a slight potential for human infection. Does this mean that a cat can transmit the disease to a person? It seems that it does because the advice is to take precautions when treating an infected cat. Transmission of the disease between cats “does not usually occur”.
The virus is the herpesvirus (Su-HV1). Although swine are reservoirs of this disease, mammals that are prone to infection are sheep, goats, dogs, rats, cows as well as cats.
As this disease is called pseudorabies it would seem to have similar symptoms to rabies but it does not in one major respect because rabid cats display aggression whereas cats with pseudorabies do not.
There is no treatment for this nasty disease and, as mentioned, once the cat is infected it almost invariably kills within 48 hours. Therefore prevention is vital. Farmers with cats should take particular note of the potential. Cats should not eat raw or undercooked pork.