Feline enteritis is the most infectious and dangerous disease of cats. In an outbreak of the disease even with the most vigorous treatment, most affected cats die.
The cause is a small virus almost identical to the virus which causes parvovirus disease in dogs. As feline enteritis is much older than the dog disease, it is quite likely that the organism affecting dogs is a variant of the cat virus.
One of the features that makes feline enteritis such a difficult disease to eradicate is the ability of the virus to survive long periods in the environment.
Sick animals or carrier animals excrete the virus in the saliva, tears, vomitus, urine and feces. In moist shady areas, such as in the cracks of cat cages and floors the virus is capable of remaining infective for at least a year.
It can be seen why the owners of pet shops, catteries or organizers of cat shows should be aware of this property of the virus.
The incubation period is quite short, usually less than one week.
- At first, the cat merely becomes very quiet, refuses all food and sits with its back hunched.
- It soon starts to vomit a bright yellow bile-stained fluid.
- It becomes progressively more depressed and tends to hide or sit with its head over its water bowl.
- Diarrhea is usually not seen as the virus attacks the very early part of the small intestine.
- Very young cats may appear sick one day and be dead the next which prompts the owner to insist that the cat has been poisoned.
- The virus attacks the cells lining the anterior portion of the bowel.
- It also attacks the bone marrow and infected cats very rapidly exhibit a marked lowering of their white blood cell counts. This robs the animal of much of its ability to fight infection.
Treatment is difficult as there is no specific drug which acts on the virus.
Blood transfusions are often given to correct the low levels of white cells present in the blood. Fluids are given to counteract the severe dehydration that quickly occurs and antibiotics are administered to prevent secondary infection in the damaged tissues of the bowel.
In general, the younger the kitten the more acute is the form the disease takes. Older cats have a better chance of recovery but it should be remembered that recovered animals can remain carriers for long periods and may be responsible for successive waves of infection in cat breeding establishments.
The virus can cross the placenta and recovered females may give birth to kittens with considerable birth defects such as abnormalities of posture or balance.
Fortunately, there is a very effective vaccine. Kittens should be vaccinated at six weeks of age if they are living in a crowded situation, such as a cattery. Another vaccination at 14 to 16 weeks confers a strong immunity.
There is some difference of opinion amongst veterinary surgeons as to when subsequent vaccination should be given. There is good evidence to suggest that another vaccination a year later confers strong immunity for at least four years.
This may be so when the animal is being regularly challenged by the virus in the community in which it lives. On the other hand, may modern cats live very sheltered lives and rarely contact other cats, these animals may lose their immunity if not regularly revaccinated.
As feline enteritis is such a serious disease and as vaccination has no ill effects, it is wise to have all cats revaccinated every year or at least every two years.