The feline immunodeficiency virus (FIV) is one of the deadliest diseases that commonly affects domesticated cats. One to three percent of healthy cats are infected with the feline immunodeficiency virus in the United States. Because the disease is most often transmitted from cat to cat through biting, indoor cats are much less likely to become infected than outdoor cats.
What is the Feline Immunodeficiency Virus?
The feline immunodeficiency virus is classified as a retrovirus, because of the way it reproduces. The virus attaches itself to a feline host cell and injects its genetic material, or DNA, into the host cell’s nucleus. The viral DNA contains instructions that make the host cell’s chemical machinery produce more viruses, which are stored inside the cell. Once the host cell has manufactured so many viruses that it cannot contain any more, the cell wall ruptures, releasing the new viruses into the cat’s body. FIV derives its name from the fact that it's designed to infect the cells of a cat’s immune system. It destroys the cat’s immune system, leaving it unprotected against other diseases that would not normally constitute a serious threat.
Symptoms of FIV
In the first stages of a feline immunodeficiency virus infection, the cat’s lymph nodes may be temporarily enlarged, and this is usually accompanied by a fever. Pet owners often overlook these first symptoms, and the infection may go unnoticed for a few years before more significant symptoms appear. As the disease develops, the cat’s general health will either progressively deteriorate, or be characterized by recurring illnesses followed by periods of relative health. Because FIV infections are characterized by numerous secondary infections, there can be a wide range of possible symptoms. Some of the most common symptoms include:
- Persistent fever
- Loss of appetite
- Poor fur condition
- Stomatitis
- Persistent diarrhea
- Eye conditions
- Cancerous tumors
- Blood disease
- Severe wasting
In rare cases, the feline immunodeficiency virus can also cause seizures, changes in behavior and other neurological disorders.
Treatment with Interferon
Interferon is a protein that stimulates the immune system in cats. It works by inhibiting the replication of the feline immunodeficiency virus inside host cells, thereby slowing the growth of the infection. It also helps the cat’s immune system identify host cells that have been infected with FIV, so those cells can be destroyed. Studies have shown a significant lengthening of the life expectancy of infected cats that were treated with interferon. This medication is administered in daily oral supplements. Interferon can be administered orally if symptoms are mild, while severe symptoms usually warrant an injection. Cats should be given 30 IU (international units) of interferon daily for seven days, followed by a seven-day period off the medication. This cycle can be repeated as long as symptoms persist.
Side Effects
Side effects of interferon use in cats are rare, but the most common are vomiting, nausea and appetite loss. Do not give your cat interferon if it already has an autoimmune disease, heart disease, the herpes virus or neurologic disorders. Rare side effects include nervous system and liver damage, as well as anemia.
The feline immunodeficiency virus can cause a host of very serious symptoms, and often results in death. As with most diseases, the key to effective treatment is early detection, so be watchful for the symptoms of this disease, and be sure to seek treatment promptly.