Panleukopenia is caused by a feline parvovirus. It is one of the most serious infectious diseases of cats, and in unvaccinated kittens it is frequently fatal.

The name describes what it does: it destroys white blood cells, so the cat loses the defences it needs at the exact moment it needs them most.

How it spreads

Through contact with the faeces of an infected cat, and through anything that faeces has touched: bowls, bedding, litter trays, hands, shoes.

The virus is exceptionally tough. It survives in the environment for months and resists most ordinary household disinfectants. This is why a purely indoor cat can catch it: the virus can be carried in on shoes.

Kittens can also be infected before birth, which damages the developing brain and produces kittens that are unsteady on their feet.

What it looks like

Onset is sudden. High fever, then lethargy and complete refusal to eat, repeated vomiting, and diarrhoea that is often bloody and has a distinctive smell. The cat becomes dehydrated very quickly. Some kittens sit hunched over the water bowl without drinking.

In the most severe cases a kitten can die within a day, sometimes before diarrhoea has even appeared.

Any unvaccinated kitten with vomiting and lethargy should be treated as a possible case.

Diagnosis

A rapid faecal test, together with a blood count. The white cell count is characteristically very low, which is where the disease takes its name.

Treatment

There is no drug that kills the virus. Treatment supports the cat while its own immune system fights, and intensive supportive care is what determines survival:

Intravenous fluids to correct dehydration and electrolyte losses
Anti-sickness medication
Antibiotics, not against the virus but against the bacterial infection that follows the collapse in white cells
Nutritional support
Strict isolation from other cats
Warmth and monitoring

Cats that survive the first few days usually go on to recover fully, and they are then immune for life.

Prevention

Vaccination is highly effective and panleukopenia is part of the core vaccine. Kittens start at six to eight weeks and the course is repeated until around sixteen weeks, because maternal antibodies block the vaccine until they have faded.

A kitten is not protected until the course is finished. Keep it away from unknown cats and from any environment where an infected cat may have been.

If you have lost a cat to panleukopenia, take advice before bringing another one into the house. The virus persists in the environment for a long time and ordinary cleaning does not remove it.