FELV and FIV in Cats: What Every Cat Owner Should Know

3 min read

As cat owners, we do everything we can to keep our feline friends healthy and happy. But two serious viral infections—Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV)—can pose significant risks to your cat’s health. While these conditions are different, both can weaken your cat’s immune system, making them more vulnerable to illness.

In this post, we’ll break down what FeLV and FIV are, how they’re transmitted, what symptoms to watch for, and how you can protect your cat.

What Are FeLV and FIV?

Feline Leukemia Virus (FeLV) is one of the most common infectious diseases in cats. It attacks the immune system and can lead to anemia, cancer, and other life-threatening conditions.

Feline Immunodeficiency Virus (FIV) is often compared to HIV in humans. It doesn’t directly cause illness, but it weakens the immune system over time, making it harder for cats to fight off infections.

Both viruses are cat-specific—meaning they cannot be transmitted to humans or other species.

How Cats Get FeLV and FIV

These viruses spread mainly through close contact with infected cats.

FeLV Transmission:

• Mutual grooming

• Sharing food or water bowls

• Bite wounds

• Mother cats passing it to kittens

  
  

FIV Transmission:

• Deep bite wounds (common in outdoor territorial fights)

• Rarely through casual contact

  
  

Indoor-only cats are at much lower risk, but exposure can happen if they come into contact with infected cats.

Signs & Symptoms to Watch For

Some cats can live for years without showing symptoms, which is why testing is so important. Common signs include:

• Weight loss

• Poor coat condition

• Persistent fever

• Loss of appetite

• Recurring infections (skin, respiratory, oral)

• Lethargy

  
  

If you notice these symptoms, schedule a vet visit promptly.

How to Test for FeLV and FIV

A simple blood test at your veterinarian’s office can detect both viruses. Vets often recommend testing:

1. Before introducing a new cat to your household

2. If your cat has been outdoors unsupervised

3. If your cat is showing unexplained illness

   
   

Early detection allows for better management of your cat’s health and helps prevent spreading the viruses to other cats.

Treatment & Management

There is currently no cure for FeLV or FIV, but cats can still live long, happy lives with proper care:

1. Routine Vet Checkups – Twice-yearly visits can help catch secondary infections early.

2. Indoor Lifestyle – Reduces exposure to new pathogens and prevents spreading the virus.

3. Good Nutrition – A balanced diet supports immune function.

4. Prompt Treatment of Illness – Even minor infections should be addressed quickly.

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💡 While medications can’t eliminate the virus, supportive care and preventative measures can significantly improve quality of life.

Prevention Is Key

🐾 Test Before Adoption – Ask shelters or breeders for FeLV/FIV test results.

💉 Vaccination – A FeLV vaccine is available and recommended for at-risk cats. There’s no widely used vaccine for FIV in the U.S., so prevention focuses on reducing exposure.

🚪 Keep Cats Indoors – Limiting outdoor access drastically lowers risk.