Understanding Feline Immunodeficiency Virus (FIV): A Guide for Pet Owners
Although cats with FIV can live normal lives for years, they eventually experience immune deficiency, allowing common bacteria, viruses, and fungi to cause severe illnesses. While there is no cure for FIV, cats with the virus can live average lifespans if they are not also infected with feline leukemia virus.
How FIV Spreads
FIV is mainly spread through bite wounds from infected cats. Casual contact, such as sharing food bowls or grooming each other, is not a common way for the virus to spread. Cats in households where they get along and do not fight are at low risk. Occasionally, an infected mother cat can pass the virus to her kittens, especially if she gets infected during pregnancy. Sexual contact is not a significant means of spreading FIV among cats.
FIV-infected cats are found worldwide, with varying prevalence. In North America, about 2.5-5% of healthy cats are infected, but this rate can be higher (15% or more) in sick or high-risk cats. Un-neutered male cats that go outside and fight with other cats are at the highest risk. There is no vaccine for FIV in North America, so keeping cats indoors and testing new cats in the household is the best prevention method.
Stages of FIV Infection
FIV infection occurs in three stages:
- Acute Phase: This phase happens 1-3 months after infection. The virus spreads to lymph nodes and multiplies in white blood cells, causing temporary lymph node enlargement, fever, depression, and lack of appetite. These symptoms are often mild and can be missed by cat owners.
- Asymptomatic Phase: This phase can last for months or years. The virus replicates slowly, and cats do not show signs of illness. However, blood tests might show abnormalities like low white blood cell levels or increased blood proteins. Some cats remain in this stage and never develop severe illness.
- Progressive Phase: As the virus spreads, cats become immunocompromised, leading to secondary infections. Most illnesses related to FIV are due to these secondary infections, not the virus itself. Cats may develop chronic or recurrent infections of the skin, eyes, urinary tract, or respiratory tract. They are also more prone to dental disease, cancer, and immune-mediated blood disorders. Weight loss, seizures, behavioral changes, and neurological disorders are possible. Once multiple severe infections or cancers occur, survival time is usually a few months.
Diagnosing FIV
It’s essential to determine the FIV status of cats when they are first acquired, if they become ill, and regularly if they are at risk.
When a cat is infected with FIV, it develops antibodies that persist in the blood for life. Blood tests look for these antibodies to diagnose FIV. A common test is the enzyme-linked immunosorbent assay (ELISA), which can be done at the vet’s office. Positive results might be confirmed with Western blot or immunofluorescence (IFA) assays at a lab.
There are scenarios when a single test may not be enough:
- Negative Test: Indicates no antibodies against FIV. However, if the cat was recently infected, it might take 2-6 months for antibodies to develop. Retesting after 60 days is recommended if exposure is possible. Rarely, cats in late-stage FIV might not produce detectable antibodies.
- Positive Test: Indicates infection. False positives are possible, so a second test is recommended for healthy cats. Kittens from infected mothers may test positive due to maternal antibodies but are often not truly infected. Retesting at 60-day intervals until six months old can clarify their status. Cats vaccinated against FIV will test positive, but there has been no FIV vaccine in North America since 2016. The PCR test can detect the virus’s genetic material but is less reliable for screening.
Managing FIV
There is no cure for FIV, but cats can live healthy lives with proper management. For healthy FIV-infected cats, the main goals are to reduce the risk of secondary infections and prevent spreading FIV to other cats. Keeping cats indoors and isolating them from other cats is crucial. Spaying and neutering reduce the risk of spreading FIV through mating or fighting.
FIV-infected cats should have wellness visits every six months, including physical exams, blood tests, and urine analysis. Monitoring their health and behavior closely is essential. Prompt treatment for any signs of illness is crucial, as these cats may need longer or more intense treatments than uninfected cats. Antibiotics might be recommended for routine procedures to prevent secondary infections.
Treatment options for the virus itself are limited. Drugs like Zidovudine (AZT) can help with severe dental inflammation or neurological disease but do not prolong survival and have serious side effects. Research is ongoing for new antiviral therapies.
Preventing FIV
The best way to protect cats from FIV is to prevent exposure. Keeping cats indoors away from potentially infected cats reduces their risk. Testing new cats before bringing them into a household with uninfected cats is ideal. If infected cats must be brought into a home with non-infected cats, separating them is best.
If FIV-infected cats have lived with other cats for years, testing all cats in the household is necessary. Separating infected and non-infected cats reduces transmission risk. FIV does not survive long in most environments, but thorough cleaning and disinfecting of food dishes, bedding, and litter pans are recommended if bringing a new cat into an environment where an FIV-positive cat lived. Using a bleach solution (four ounces of bleach in one gallon of water) is effective for disinfection. New cats should be vaccinated against other infectious agents before entering the household.
Conclusion
FIV is a significant concern for cat owners, but with proper understanding and management, infected cats can lead long, healthy lives. Preventing exposure, regular health monitoring, and prompt treatment of secondary infections are key to managing FIV. By keeping cats indoors and maintaining a stable social environment, the risk of FIV transmission can be minimized, ensuring a better quality of life for all cats in the household.