Feline Immunodeficiency Virus (FIV) Symptoms and Management

ImmunityQ&AMeongsiljang Veterinary Advisory Board

I’ve compiled a summary of feline immunodeficiency virus (FIV) infection routes, major symptoms, diagnosis and treatment, and care guidelines for pet owners, based on veterinary textbooks.

What is Feline AIDS (FIV)?

Feline immunodeficiency virus (FIV) is a retroviral infection that gradually weakens a cat’s immune system. The most critical aspects are early detection and lifelong management. While there is no cure for FIV, with proper diagnosis, many cats can live long lives indoors, just like other cats. Although its name is similar to human HIV, which often leads to misunderstandings, FIV is not transmissible to humans or dogs. It is important to remember that this virus only spreads among cats.

How is it Transmitted?

Feline immunodeficiency virus (FIV) is primarily transmitted when the virus in saliva enters the bloodstream through deep bite wounds. Consequently, cats that fight frequently—such as outdoor cats, stray cats, and intact males—have a higher infection rate. Transmission is extremely unlikely through shared food or water bowls or mutual grooming, and the virus is not airborne. Vertical transmission from mother to kitten during pregnancy or birth is possible but rare.

Infection Stages and Progression

FIV doesn't manifest all at once but progresses gradually through several stages. The table below summarizes the characteristics of each stage.

Characteristics of Each FIV Stage

Item	Acute phase	Asymptomatic phase	Chronic phase
Duration	A few weeks to about 3 months after infection (viremia peak: 8–12 weeks)	Several months to several years	Several months or more
Main symptoms	Fever, swollen lymph nodes, decreased appetite	Appears healthy externally	Recurrent infections, weight loss, stomatitis
Viral activity	Actively replicating	Latent	Immune collapse
Owner's perception	Similar to a cold	No abnormality	Frequently ill

The progression speed varies greatly between individuals, and some cats maintain the asymptomatic phase for several years or more.

Key Symptoms Owners Should Know

In cats with FIV, the primary concern is not the virus itself but rather secondary conditions arising from a weakened immune system. If you notice any of the following signs recurring, FIV should be considered as a possible cause. - Chronic stomatitis: The gums become red and swollen, causing pain during meals. - Recurrent cold-like symptoms: Nasal discharge and sneezing persist for extended periods or frequently recur. - Weight loss: The cat becomes thin despite maintaining a normal appetite. - Gastrointestinal issues: A compromised immune system can lead to recurring digestive discomfort and various related symptoms. - Skin and coat abnormalities: Immunosuppression can result in secondary bacterial or yeast infections, leading to recurring skin problems. - Swollen lymph nodes: Enlargement may be noticeable under the chin or in the armpits.

A veterinarian examining a cat's gum condition.

Go to the Vet Immediately If You See These Signs

If your cat’s gum bleeding doesn’t stop, if they refuse to eat for several days, if their breathing becomes rapid, or if you notice pus-like discharge from their eyes or nose, their immune system may be collapsing. These symptoms are especially concerning in cats rescued from the streets or in multi-cat households shortly after introducing a new cat. In such cases, don’t dismiss these signs as a simple cold—seek veterinary care that includes testing for FIV (Feline Immunodeficiency Virus).

How is Diagnosis Performed?

FIV diagnosis typically begins with a simple in-clinic test using just a drop or two of blood. Veterinarians often use combination kits that also screen for FeLV (feline leukemia virus) at the same time. However, in kittens under six months old, maternal antibodies may still be present, leading to false-positive results, while early-stage infections may not yet have produced enough antibodies, resulting in false negatives. Veterinary internal medicine textbooks recommend retesting after several weeks or performing PCR testing if suspicious symptoms persist.

The Core of Treatment and Lifelong Management

While there is no cure to completely eliminate the FIV virus, quality of life can be maintained through management-focused treatment that prevents secondary infections. - Strict indoor living: Prevents fights with other cats and reduces exposure to external pathogens. - Regular health check-ups: Blood tests and weight checks are recommended every six months. - Oral care: In cases of severe stomatitis, tooth extraction can significantly improve quality of life. - Neutering: Reduces risks associated with territorial disputes and roaming. - High-quality, high-protein diet: Maintaining muscle mass is essential. - Minimizing stress: Stress is a factor that can accelerate immune suppression.

For Multi-Cat Households, Do This

According to recent veterinary internal medicine textbooks, FIV-positive cats and uninfected cats can live together in the same household as long as they do not fight. The key is to prevent injuries. During the initial introduction phase, keep them in separate spaces to allow them to adjust to each other, and gradually introduce them after both have been neutered or spayed. Providing separate food bowls and litter boxes helps manage stress.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Can cats with FIV still live a long life?

Yes, with proper indoor care and minimal stress, many cats can live for over 10 years. The key is to promptly address secondary infections and keep up with regular veterinary check-ups.

Can it be transmitted to humans?

No, FIV is a **cat-specific virus** that cannot be transmitted to humans or dogs. You can rest assured.

Is there a vaccine available?

In Korea, the FIV vaccine is not commonly used. Keeping your cat indoors and preventing fights are far more effective measures than vaccination.

Can FIV-positive cats undergo surgery?

Yes, surgeries like neutering and tooth extractions are perfectly fine as long as your pet’s health is stable. You can schedule the procedure with your veterinarian based on the blood test results.

Does a positive result on the rapid test kit confirm the diagnosis?

Not necessarily. In particular, kittens under six months old or those in the early stages of infection may yield false results, so a follow-up test after several weeks or a confirmatory PCR test is recommended.