01 October 2010

Shield your cat from this killer

Cat lover? Then you'll want to protect your feline friends from feline leukaemia virus – a fairly common, highly contagious and deadly disease.


For any cat lover, losing a cat is painful. To lose a kitten that's only a few months old, feels tragic. And when, two weeks later, you discover your other kitten has incurable feline leukaemia, you swear you'll never have a pet again.

I should know, and 2007 will forever be engraved in my mind as The Year of The Cat – the sick one, that is.

After our 11-year-old cat unexpectedly died, presumably of a heart attack or stroke, we decided to get two kittens.

Both looked fine at first, but Nina, the female, soon developed diarrhoea. It took three days of intensive treatment in hospital to sort her out, and for a while afterwards her immune system wasn't on a par with that of Lukas, her brother.

Then Lukas, too, became ill. That's when we found out that both our Animal Welfare orphans had feline leukaemia virus – a fairly common, highly contagious and lethal disease.

Sadly, Lukas didn't make it. Nina is still hanging in. So, in a humble effort to protect future feline generations and to alert fellow cat worshippers to the dangers of the disease, I approached our vet and asked a few essential questions:

What is feline leukaemia virus?
As the name implies, feline leukaemia virus (feLV) is not a form of cancer, but rather a retrovirus like HIV in humans. It differs genetically from feline immunodeficiency virus ("cat Aids"), even though the two diseases are from the same family.

"Practically, feline leukaemia affects a much younger age group than feline immunodeficiency virus," says Dr Stephen Maberly from the Goedemoed Animal Hospital in Durbanville.

Like other forms of leukaemia, the disease suppresses the bone marrow, which leads to an overproduction of large, abnormal white blood cells.

Cats with feLV can get seriously ill and emaciated in a very short period of time. And it's fairly common. The vets at Goedemoed Animal Hospital treat at least one or two cats with feLV every week.

How do cats get it?
According to Maberly, the disease is mainly contracted through fighting, where an uninfected cat comes into contact with the blood of an infected cat.

Experts generally agree that the virus can also be spread through other bodily excretions, e.g. saliva, tears, faeces and urine. This means that cats who share the same household can easily infect each other through grooming, or via litter boxes. The virus can also be transmitted from a mother cat to her kittens.

Kittens younger than four months and immune-compromised adult cats are at greatest risk of infection.

How will I know if my cat has it?
Many cats with feLV will appear healthy for a very long time, Maberly says. This is when the disease is in the latent stage.

However, as the disease progresses the following symptoms may become apparent:

  • loss of appetite;
  • weight loss;
  • fever;
  • diarrhoea;
  • vomiting;
  • pale gums; and
  • poor coat condition.

As feLV suppresses the immune system, a sick cat will also be more prone to secondary infections from viruses, bacteria and fungi. These may present in skin, bladder, gut or chest infections. The cat's risk of developing cancer will also be higher.

Blood tests can confirm the feLV diagnosis.

Can feLV be treated?
While there is no cure for feLV, disease progression can be slowed down with appropriate treatment.

Maberly explains that many cats get a transient form of infection when they first contract the disease. At this stage, their bodies either kill off the disease and they recover completely, or it remains in their system in the latent form, when they don't display any symptoms but are still infected. Should the latter occur, the disease will eventually progress to the clinical, and critical, stage.

If the disease is in the transient stage, the cat can remain healthy for a long time and may even overcome the disease. At this stage, certain immune-boosting medication and good nutrition can play an important role.

However, if a cat already has the persistent form of feLV, it won't respond to medication, and the cat will eventually die. According to Maberly, 30% of cats who are at this stage of the disease die within six months, 60% die within two years and 90% die within four years.

How can I prevent my cat from getting it?
Vets agree that the best way to protect cats is to make sure they get their feLV shots.

"The efficacy of the vaccine is pretty good," Maberly says. But he notes that there's a risk involved: it may increase a cat's risk of sarcoma, i.e. cancer of the connective tissue.

For this reason, it's generally recommended that kittens get vaccinated only twice, at nine and 12 weeks respectively.

If there's an increased risk that the kitten might contract the disease, more vaccinations may be necessary. Note, however, that it's not wise to introduce a new cat to a home that hosts an infected cat.

It may also be a good idea to limit contact with other cats by keeping your cat indoors or within the boundaries of your property.

What should I do if my cat has been diagnosed with feLV?
Maberly has the following advice:

  • be on the lookout for disease symptoms;
  • monitor your cat for secondary problems;
  • make sure your cat has access to good quality food;
  • consider giving your cat immune-booster medication; and
  • take your cat for a check-up every three months.

(Carine van Rooyen, Health24, updated September 2010)

- Cornell University College of Veterinary Medicine


- Last updated: June 2010

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