FIV and FeLV: How to Tell The Difference
When cat lovers hear the terms FIV and FeLV, they often assume they are the same disease. And far too often, these cats are overlooked for adoption because of this misunderstood virus.
While they both affect cats and are viral infections, they are actually different conditions with unique ways of transmission, health impact, and long-term outcomes.
FIV - Feline Immunodeficiency Virus:
FIV is a species-specific virus that cannot be transmitted to humans or other non-feline animals. Unneutered males are at a higher risk of contracting FIV than females. Male cats are more susceptible to this virus due to territorial aggression, which is the primary mode of transmission. It is rarely transmitted from mother to kittens.
Unlike FeLV, cats are at low risk of contracting this virus through food and water bowls, grooming, or sleeping together.
Furthermore, cats with FIV, with proper care, can lead normal lives. Many cats infected with this virus show no symptoms for years after infection.
However, in the case of a free-roaming cat, especially a male displaying signs of recurrent infections, weight loss, poor coat maintenance, fevers, slow wound healing, chronic eye inflammation, or other abnormal health symptoms, it is crucial for you to seek veterinary care.
FeLV - Feline Leukemia Virus:
FeLV is the primary infectious disease killing cats. Unfortunately, 85% of infected cats die within three years of diagnosis. However, it doesn't have to be a death sentence.
FeLV suppresses the immune system and causes various health problems such as cancer, organ failure, severe infections, and even anemia.
This disease is highly contagious and easily spreadable. The primary sources of contracting this infectious disease can include deep bite wounds, sharing litter boxes, or being passed from an infected mother cat to her kittens.
Having volunteered around cats for decades, I have personally witnessed infected mother cats transmitting the virus to their kittens. It is reasonable to assume that the virus is passed on through nursing, given the close contact between the mother cat and her kittens. Unfortunately, younger cats that contract this deadly infectious disease have a higher likelihood of succumbing to it, but with proper care, they can survive, as I have experienced a cat living to be 21 years old.
If you have a free-roaming cat suffering from persistent fevers, loss of appetite, chronic respiratory infections, diarrhea, or reproductive problems, as with FIV, it is imperative to seek medical attention immediately.
Although there is no cure for either of these viruses, early prevention is critical.
Despite the grim prognosis, it doesn't mean your cat can't live a healthy, long-term life. Regrettably, many cats are euthanized simply because they have these viral infections and are often overlooked for adoption. I comprehend the reservations about adopting these cats, primarily due to the financial and emotional burdens.
Some of my favorite training cats, with whom I volunteer, have succumbed to feline leukemia virus, and it was emotionally challenging. However, these beautiful, loving cats also deserve homes.
Cats with FIV and FeLV make wonderful pets. It is crucial to gain a deeper understanding of these two viruses and recognize the differences between them because they are not the same. One common aspect they share is that cats with either virus often do not have the chance to live a healthy, normal life since their light is dimmed prematurely.
For more information on Feline Immunodeficiency Virus and Feline Leukemia Virus check out these links below 🐱
https://catvets.com/wp-content/uploads/2024/10/FelineVMA_FeLV-and-FIV-Broch_Web.2.pdf
The more you know, the better you will understand these two viruses.
Disclaimer
The information and product recommendations provided by Totally Feline™ are for educational purposes only and are not a substitute for professional veterinary advice. Always consult your veterinarian regarding your pet’s care.
Copyright© 2026 Totally Feline™ Totally Feline CC ™ . All rights reserved. Content, images, and materials may not be reproduced, distributed, or used without written permission.