Feline leukaemia virus - often referred to as FELV - is a virus that is spread from cat to cat. It’s doesn’t affect dogs or people.

FELV is usually spread when cats fight with each other – the virus is present in cats’ saliva, and hence is easily passed from cat to cat when they attack each other. But it’s also possible for cats that live in close contact to infect each other - especially when they participate in mutual grooming.

Understanding FELV in cats

We’re finding that the condition is becoming more and more prevalent in South Africa, mainly because people are living in close contact with one another – think apartment blocks, complexes and estates – which causes cats’ territories to overlap. Turf wars often lead to cats fighting with each other, which as we’ve noted, is what usually causes the spread of FELV.

What effect will FELV have on my cat?

FELV results in immune system suppression and causes the formation of cancer – leukaemia and lymphoma in cats.

When a cat is initially infected, they don’t appear sick. In fact, they can remain in an asymtomatic phase for months or even years. However, it’s crucial to note that they can still be contagious during this period, even when displaying no symptoms.

Some cats can even become carriers, which means that the virus is not making them sick but they are still able to transmit the virus to other cats and make them ill.

Clinical signs of FELV in your cat and testing for the disease

If you notice any of these symptoms in your kitty, get them to your vet as soon as possible:

  • General poor condition
  • Weight loss
  • Gets sick often and easily – FELV weakens the immune system
  • Lumps, like enlarged lymph nodes
  • Anaemia (look for pale gums)
  • Signs of leukaemia and lymphoma

Your vet will perform a quick, simple test in their rooms, which takes a few minutes. Usually FELV and FIV are tested for simultaneously.

My cat has tested positive for FELV. How do I treat her?

FELV is a chronic, life-long condition; there is no cure. Therefore, treatment is supportive, and aimed at keeping your furbaby as healthy as possible for as long as possible. Stick to these steps as much as you can:

  • Keep her up to date on all her vaccinations, and deworm her regularly.
  • FELV-positive cats are more susceptible to infections and blood parasites, so flea and tick control is super important.
  • Feed her the best possible diet you can. Avoid supermarket food and raw diets, the latter of which is high in bacteria. Bacteria can easily be handled by a healthy cat with a properly functioning immune system, but can cause serious illness in animals with compromised immune systems.
  • Talk to your vet about Immune boosting supplements.
  • Test all cats in your household so you know the status of each cat. This means that if one of your cats get sick, you can get the right treatment quickly.
  • Keep FELV-positive kitties indoors. This will also help protect them from picking up illnesses from other cats.
  • Spay and neuter your kitties to help reduce their desire to roam and fight. This is one of the best ways to help protect them against disease.

Is there an FELV vaccination?

Yes there is. These vaccinations are available from your vet, though they don’t form part of the core annual vaccinations that your cat receives. You need to specifically request it, and your vet will probably ask to perform an FELV test prior to giving the vaccination, to ensure your cat is negative to start with.

After a cat has been vaccinated, the test is no longer accurate, as it may give a false positive reading as a result of the vaccine.

What’s the difference between FELV and FIV (feline AIDS)?

FELV and FIV are two different viruses that are often confused with one another.

They are similar to each other in that that they are both transmitted from cat to cat, mostly via saliva during fighting, but also possibly through regular mutual grooming. Both diseases cause weakening of the immune system, and it’s possible to be infected with both viruses at the same time.

Read more about FIV – feline immunodeficiency virus (feline AIDS).

Remember: neither FELV or FIV is a death sentence for your kitty. Animals can live long, relatively healthy lives with these diseases - it’s all about how you manage their health and their lifestyles. That’s why it’s important to keep a close eye on your pets, and to have them checked out as soon as they appear unwell.

Here’s hoping that all of your cat’s nine lives are happy, healthy and FELV-free!


Disclaimer: Always consult your vet for professional advice. The Zuki.co.za blog is provided as an educational tool and should not be used to diagnose illness or treat an animal.

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