Feline leukemia virus affects a cat in many ways. It is the most common cause of cancer in cats, it may cause various blood disorders, and it may lead to a state of immune deficiency that hinders the cat’s ability to protect itself against other infections.
The same bacteria, viruses, protozoa, and fungi that may be found in the everyday environment – where they usually do not affect healthy animals – can cause severe illness in those with weakened immune systems.
These secondary infections are responsible for many of the diseases associated with FeLV. How common is the infection? FeLV-infected cats are found worldwide, but the prevalence of infection varies greatly depending on their age, health, environment, and lifestyle. In the United States, approximately 2% to 3% of all cats are infected with FeLV. Rates rise significantly – 13% or more – in young kittens and cats that are ill, or otherwise at high risk of infection.
How is FeLV spread? Cats persistently infected with FeLV are themselves sources of infection. Virus is shed in very high quantities in their saliva and nasal secretions, but also in urine, feces and milk. Cat-to-cat transfer of virus may occur from a bite wound, during mutual grooming, and through the shared use of litter boxes and feeding dishes. Transmission can also take place from an infected mother cat to her kittens, while they are nursing or even before they are born.
What are the signs of FeLV? During the early stages of infection, it is common for cats to exhibit no signs of disease at all.
Over time, however, the cat’s health may progressively deteriorate or be characterized by recurrent illness interspersed with periods of relative health.
Signs can include:
- Loss of appetite
- Slow but progressive weight loss
- Poor coat condition
- Enlarged lymph nodes
- Persistent fever
- Inflammation of the gums and mouth
- Infections of the skin, urinary bladder, and upper respiratory tract
- Persistent diarrhea
- Seizures, behavior changes, and other neurological disorders
- A variety of eye conditions
- In unspayed female cats, miscarriage of kittens or other reproductive failures
How can I keep my cat from becoming infected? The only sure way to protect cats is to prevent their exposure to FeLV-infected cats. Keep cats indoors, away from potentially infected cats that might bite them.
Adopt only infection-free cats into households with uninfected cats. House infection-free cats separately from infected cats, and don’t allow infected cats to share food and water bowls or litter boxes with uninfected cats. Consider FeLV vaccination of uninfected cats. Discuss the advantages and disadvantages of vaccination with your veterinarian.
