Urban Jungle

PUBLISHED : Friday, 28 March, 2008, 12:00am
UPDATED : Friday, 28 March, 2008, 12:00am

This week: parvovirus infection

There was disturbing news this week from a little-known northern province of Thailand, Phichit. It's not the usual holiday destination for Hong Kong tourists, so most of us haven't heard of it. It was reported a group of cats had been found dead after suffering such symptoms as vomiting, lethargy, diarrhoea and upper airway infection. Laboratory tests are being conducted by the local authorities to determine the cause of death. Feline distemper is suspected by the disease control department of the Ministry of Public Health.

It was in the same province in 2006 that two human patients contracted flu-like symptoms after coming into contact with dead chickens. The area was declared a bird-flu red zone and citizens were warned by authorities not to eat chickens that died. It was feared poor immigrants would eat dead chickens and risk contracting bird flu. There is no evidence of any link between bird flu and the dead cats.

News of the dead cats has locals, mindful of the bird-flu scare, on high alert and wrongly fearful of contracting bird flu from the dead cats. Cat owners have been abandoning their cats and sometimes dogs at Buddhist temples, where monks are obliged to help the newly arrived homeless animals. The monks have issued a plea to people to stop dumping their cats at temples, where they make a nuisance of themselves by fighting and defecating.

Given the symptoms the cats suffered before their deaths, the disease is unlikely to be bird flu. Gastrointestinal symptoms are not usually involved in bird flu, and I agree with the local authority's suspicion of feline distemper.

So what is feline distemper and how does it affect us in faraway Hong Kong? Among cat owners in Hong Kong, feline distemper is more commonly known as feline panleukopenia. It is caused by a parvovirus. The virus is not able to cross between different species, so it can't be transmitted to humans or dogs. Dogs have their own version of parvovirus that isn't related to the cat version.

The virus in cats infects the rapidly dividing cells of the body, such as those of the intestinal lining. It causes ulcers in the intestinal lining which lead to diarrhoea and vomiting. If severe enough, the animal can die from dehydration or a secondary infection from bacteria entering the blood stream through a wound in the intestinal lining.

The other system affected is the bone marrow, which is constantly producing the body's white blood cells. This is where the disease gets its name. The word 'pan-leuko-penia' literally translated from Latin is 'all white blood cell decreased'. White blood cells are part of the body's basic defence system and if they are compromised, the animal's immune system becomes depressed and much more susceptible to respiratory and intestinal infections.

Parvovirus is present in Hong Kong, but diagnosed cases are uncommon. The virus is very persistent and can survive commonly used disinfectants. It can stay around for months in suitable indoor environments.

It is mostly a problem in catteries, shelters, cat hotels and pet shops. Kittens are especially susceptible. The virus usually remains dormant until the weather becomes warm. When cats are in stressful situations, such as being housed closely together, there can be an outbreak. If an infection is not detected early and treated appropriately, the death rate is up to 90 per cent. The few cats that survive will develop resistance to the virus for life.

Fortunately, there is an effective vaccine available that cats can be given annually. Thai authorities are advising owners to get their cats vaccinated rather than dump them. Vaccination is also recommended in Hong Kong. The vaccine commonly used is a combination dose that also vaccinates against feline herpes and calicivirus, both of which are causes for the common cat flu, which in many ways is even more disastrous than feline panleukopenia.

Vaccines are not expensive. Most of the cost to you, the pet owner, for an annual vaccination is and should be towards the vet's time in examining your animal and giving you relevant information that can forestall future health problems.

I recommend owners stay alert about their cats' condition and health. Consult your veterinarian if you notice abnormal behaviour, lumps, limping, discharges, loss of appetite, marked weight loss or weight gain, abnormal urination or defecation, excessive scratching, licking and head shaking, any ulceration or sores on the skin, excessive drinking, any eye problems, excessive dandruff or dullness to the coat, foul breath and lots of tartar on teeth. That covers all the common signs owners can detect themselves. With observation, a good diet and a close relationship with your vet, you have the formula for a healthy and happy companion.