By Dr. Becker
Feline immunodeficiency virus (FIV) is a lentivirus, or "slow virus," that multiplies slowly and has a long incubation period before causing symptoms. Immunodeficiency means the body is unable to mount a normal immune response.
FIV belongs to the same class of viruses as the human immunodeficiency virus (HIV), which is the precursor of AIDS. But don't panic — humans can't get FIV and cats can't get HIV. FIV is also in the same retrovirus family as the feline leukemia virus (FeLV), but there are several differences between the two.
For example, the FIV virus has an elongated shape, while FeLV is more circular. The viruses are genetically quite different, as are the proteins they contain. The ways in which FIV and feline leukemia virus cause disease also differ.
Cats at Highest Risk for the Feline Immunodeficiency Virus
Cats infected with FIV are found worldwide, but with dramatically varying infection rates. In the U.S., it's estimated that between 1 and 15 percent of cats could be infected, depending on immune status and exposure risk.
FIV is seen most often in free-roaming, aggressive male cats. Indoor kitties are much less likely to be infected. The average age at diagnosis is 5 years, and the risk of infection increases with age.
There is no genetic predisposition for the condition, although genetics may play a role in disease progression and severity.
FIV is transmitted primarily through bite wounds. Casual contact doesn't appear to spread the virus, which is why friendly kitties in stable multi-cat households are at little risk of acquiring FIV.
Rarely, an infected mother cat can transmit the virus to her kittens either during passage through the birth canal or while nursing. Sexual contact is not considered a major means of transmission.
Symptoms of an FIV Infection
A cat with an FIV infection can appear normal for years. But eventually, the disease creates a state of immune deficiency that leaves the kitty susceptible to other infections.
This means that everyday bacteria, viruses and fungi that cause no problems for healthy animals can cause serious illness in kitties with compromised immune systems. Secondary infections are responsible for many of the diseases that are linked to FIV.
Early in an FIV infection, lymph nodes throughout the body are affected, resulting in temporary enlargement of the nodes, and often, a fever. This stage of infection often passes unnoticed unless the lymph nodes grow markedly enlarged.
The course of FIV can cause a progressive deterioration of health, or recurrent bouts of illness interspersed with periods of relatively normal health. Symptoms of immunodeficiency can occur anywhere in a cat's body and include:
Recurrent minor illnesses, often involving the upper respiratory tract and gastrointestinal tract Persistent bacterial or fungal infections of the ears and skin Inflammation of the gums is seen in 25 to 50 percent of cases Fever and wasting, especially in the later stages Upper respiratory tract disease is seen in 30 percent of cases Cancer, especially lymphoma Chronic eye problems, glaucoma Nervous system abnormalities, including disruption of normal sleep patterns, behavioral changes such as pacing and aggression, changes in vision and hearing, and disorders affecting the nerves in the legs and paws Chronic kidney insufficiency Poor coat condition Persistent diarrhea is seen in 10 to 20 percent of cases
Your veterinarian will perform a thorough physical exam on your cat and take a history of symptoms, noting any events that might have put him at risk for infection. He or she will also run a complete blood profile, including a chemical blood profile, a complete blood count, and a urinalysis, and will need to rule out infections, parasites, and tumors.
An antibody test is used to check for the presence of FIV antibodies in the blood of infected kitties. However, false-positive results do occur, so it is recommended that a positive antibody test result be confirmed using a different type of test, typically a polymerase chain reaction (PCR) test.
Infected pregnant cats will transfer FIV antibodies to nursing kittens, and those babies may test positive for several months after birth. Fortunately, most of them aren't and won't become infected. Kittens under 6 months that test positive should be retested every 60 days until they are at least 6 months old.
Cats who test negative for FIV, but have had a known or unknown exposure through a bite from another cat should be retested a minimum of 60 days after their most recent exposure. This is because it takes 8 to 12 weeks – and sometimes even longer – before detectable levels of antibody appear.
Once in a great while, a kitty with advanced FIV tests negative because her immune system is so compromised that it can no longer produce detectable levels of antibody.
There is no specific treatment for kitties with feline immunodeficiency virus, however, any existing secondary infections will need to be treated.
FIV-positive cats should be kept indoors, which will prevent the spread of the virus to other cats, while also reducing the risk that your kitty will be exposed to pathogens her immune system may not be able to handle. FIV-positive cats should not breed.
Your cat should be fed a balanced, nutritionally complete species-appropriate diet. Unless your kitty has a low white blood cell count – in which case I recommend cooked fresh food – a raw diet is fine. You can also feed commercially available sterile raw food that has been high-pressure pasteurized (HPP'd).
Cats with FIV should see the veterinarian at least twice yearly to review the health of their eyes, gums, skin and lymph nodes, and to check their weight. At one of the two yearly visits, bloodwork and a urinalysis should be performed. Careful, consistent monitoring of your FIV-positive kitty's health and behavior is extremely important so that you can notify your vet right away of any changes.
I've had good success keeping my FIV-positive patients very healthy using a variety of natural supplements to support the immune system, including medicinal mushrooms, Standard Process Feline Immune System Support and Whole Body Support, turmeric, Kyosenex thymus extract, Chinese herbs, and FIV homeopathic nosodes.
Ozone therapy can also be very beneficial for FIV cats.
Outlook for Cats with FIV
Many cats with FIV live normal or near-normal life spans with good quality care, so please don't listen to vets that suggest euthanasia just because your cat tested positive for the infection!
Unfortunately, it's impossible to predict how long or how well a cat will survive after diagnosis. Cats that develop serious illnesses secondary to an FIV infection have a less hopeful prognosis, as do kitties with persistent fever and progressive weight loss. FIV positive cats should never be vaccinated for anything, ever.
The only foolproof way to keep your cat safe from FIV is to prevent exposure to the virus. This obviously means keeping her away from potentially infected cats.
If your cat goes outdoors, it should be under your close and constant supervision, or in a safe, secure outdoor enclosure – one that prevents other cats not only from getting in, but from being able to bite or scratch your kitty through the sides or top of the enclosure.
If you have an uninfected cat, never allow untested or at-risk kitties to mingle with yours. It's possible to have FIV-positive and negative cats living under the same roof, as long as they don't fight or bite. I do not recommend the FIV vaccine, as it's often ineffective and has been linked to the development of vaccine-associated sarcomas in cats.