Understanding Feline Immunodeficiency Virus (FIV) Title

Photo Credit: Rocky Mountain Feline Rescue via Flickr

The Feline Immunodeficiency Virus (FIV) is one of the most misunderstood illnesses affecting cats. Very often FIV is confused with another illness caused by a retrovirus – Feline Lukemia (FeLV). The two illnesses have some similarities, but are actually very different. FIV is to cats what HIV is to humans. It is a serious illness, but when treated with care, an FIV+ cat can live a fairly normal life.

What is FIV?

FIV is a virus that uses a cat’s white blood cells (cells responsible for much of the cat’s immune response) for it’s own reproduction. Of course, by using this method of reproduction FIV destroys the cat’s white blood cells and, thus, its immune system. Ultimately, FIV is a fatal disease. Cats do not die as a direct result of the virus itself, but rather from secondary infections that their body is unable to fight off.  FIV does not affect humans, there’s no need to worry about catching FIV from your cat.

According to Cornell University, 1.5% – 3% of otherwise healthy cats in the U.S. is FIV positive. This number jumps 15% of cats that are sick. FIV is not localized to the U.S., but can be found throughout the world. World wide the prevalence is around 2.2% – 4.4%.

Symptoms of FIV

The symptoms of FIV are very non-specific. Cats may not display symptoms for years after they have been infected. Cats suffering from FIV may have any of the following symptoms. If you are concerned that your cat may have FIV, contact your veterinarian.

Dec 11, 2009 5:20 PM: Annie

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  • Gingivitis
  • Stomatitis – swollen mouth.
  • Cuts or sores that heal very slowly or not at all.
  • Frequent upper respiratory infections
  • Enlarged lymph nodes
  • Fever
  • Weight Loss
  • Diarrhea
  • Conjunctivitis – inflammation or abnormal appearance of the eye.
  • Skin redness or hair loss.
  • Seizures or other neurological disorders.
  • Behavioral changes
  • Disheveled coat.
  • Poor appetite.
  • Difficulty with urination or going outside the litter box.

FIV Progresses in 3 Stages

  1. The Acute Stage, occurs 4 to 6 weeks after the initial infection. The virus first moves to the closest lymph nodes, where begins reproduction in the white blood cells there. There are symptoms at this stage (swollen lymph nodes, fever, low white cell count), but they are temporary and easy to miss.
  2. The Subclinical Stage. The cat will not likely show any symptoms at all. This second stage could last anywhere from months to years.
  3. The Chronic Clinical Stage. The virus has progressively moved throughout all of the lymph nodes of the body. The immune system has been drastically weakened or eliminated by FIV. Symptoms begin showing up frequently and even the smallest infections become life threatening.

How is FIV Transmitted?

FIV is most frequently transmitted from a cat’s saliva directly into another cat’s blood stream by way of deep bites that occur during fights. It is possible but unlikely to transmit FIV by sharing food dishes, social grooming, and other intimate social contact. Even sexual activity between cats is not a likely way to transmit FIV, though FIV has been found in cat semen. Kittens can contract FIV from their mother during birth or from drinking their mother’s milk, but this is pretty rare. Male, outdoor, un-neutered cats are the most likely to be FIV positive because of the frequency with which they fight. Indoor only cats are the least likely to be FIV positive.

Diagnosis of FIV

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Antiobody tests for FIV and FeLV Photo Credit: Rocky Mountain Feline Rescue via Flickr

Cats are most frequently diagnosed with FIV around the age of 5. The most common and reliable way to determine if a cat is FIV positive is through an antibody test. A simple blood test at the vet that can take as few as 8 minutes can detect the particular antibodies a cat’s immune system creates to defend itself against FIV. These tests can be inaccurate if the cat is a kitten under 6 months of age, has received the FIV vaccine, or is recently infected.

Treatment and Home Care

There is no cure for FIV. Supportive treatments including anti-inflammatory drugs, antibiotics, immune-enhancing drugs, fluid or electrolyte replacement therapies, etc may be used to treat symptoms and secondary infections. A cat that is diagnosed early may have many years of relatively normal health and quality of life. It may not be necessary to take any drastic measures right away.  Some things that may help your cat include:

Austin Community College Vet Tech Program

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  • Vet check ups twice per year. This will allow you and your veterinarian to track the progression of the FIV. Catching symptoms early can help slow down the disease.
  • A diet high in protein and other essential nutrients. Good nutrition supports good health. An FIV positive cat may have special dietary needs. Do not feed raw meat or eggs because of the potential for bacteria and other things that could tax your cat’s weakened immune system.
  • Keep the cat indoors. Doing this will lessen your cat’s chances of secondary infection and keep other cats from becoming infected.
  • Get the cat spayed or neutered. Cats that are not spayed or neutered tend to be more territorial and fight more. Less fights equal less infections and cuts that have to heal.
  • Keep a careful eye on your cat. Be extra mindful of the symptoms your cat is displaying. Even small changes need to be reported to the vet.
  • Use parasite controlling treatments. Since fleas, ticks, and other parasites can carry infectious agents you will need to be extra careful that they don’t feed on your cat.

What about the Vaccine?


Photo Credit: Rocky Mountain Feline Rescue via Flickr

The FIV vaccine is very controversial. Your veterinarian can help you weigh the risks and benefits of your cat receiving the vaccine. The biggest concern about the vaccine is that it will cause your cat to test positive for FIV for the rest of its life. This means that if an animal control officer happens to find your cat wandering about outside, it could be euthanized at the Animal Shelter for being FIV positive. Another concern is that the vaccine is not effective enough; there are 5 different strands of FIV and the vaccine uses only 2 of them.  Some veterinarians are also concerned about some of the ingredients in the vaccine. There is an ingredient in the FIV vaccine that is linked to tumors that grow at vaccine injection sites in cats.

Should I Adopt an FIV Positive Cat?

Absolutely! These cats are perfect for you if you either don’t have any other cats or if your other cats are FIV positive as well. Some veterinarians even say that it is okay to have FIV positive cats with FIV negative cats as long as the cats are not fighters. As previously mentioned, cats with FIV can live a normal life for several years. These cats will not necessarily burden you with extra medical expense. When living in a low stress environment with proper medical care, FIV positive cats have a great quality of life for many years. They are perfectly loving, playful pets!

Have you ever known someone with an FIV+ cat?

Sources and Digging Deeper

Feline Immunodeficiency Virus – Veterinary at Cornell

Feline Immunodeficiency Virus (FIV) – ASPCA

FIV or Feline AIDS in Cats – PetMD

Feline Immunodeficiency Virus (FIV) in Cats – Pet Education

Feline Immunodeficiency Virus (FIV) – International Cat Care

Feline immunodeficiency virus (FIV) as a model for study of lentivirus infections: parallels with HIV. – Elder, JH, et al.