Diseases Covered by the FVRCP Vaccine in Cats
The FVRCP vaccine is a core immunization for all cats, whether they spend their days indoors or venture outside. This combination shot shields felines from three major, potentially life-threatening illnesses: Feline Viral Rhinotracheitis (FHV-1), Feline Calicivirus (FCV), and Feline Panleukopenia (FPL). Understanding these diseases—and how vaccination protects your pet—can help you make informed decisions about your cat's health.
1. Feline Viral Rhinotracheitis (FHV-1)
This disease is caused by the herpesvirus type 1. It's responsible for a staggering 80–90% of infectious upper respiratory problems in cats. The virus targets the nose and windpipe, sometimes complicating pregnancies. Typical symptoms include:
- Fever
- Sneezing
- Inflamed eyes and nose
- Discharge from eyes and nose
While adult cats may show only mild discomfort, severe cases can drag on for six weeks or more. Vulnerable groups—like kittens, senior cats, or those with weak immune systems—may face persistent depression, appetite loss, dramatic weight loss, and mouth sores. Bacterial infections often pile on top of viral symptoms. Even after visible signs fade, the virus can hide in the body and flare up later.
2. Feline Calicivirus (FCV)
This virus is another major culprit behind feline upper respiratory infections and oral disease. FCV spreads through saliva and discharges from the nose or eyes; sometimes even urine or feces can carry it. Signs to watch for include:
- Nasal congestion
- Sneezing
- Eye inflammation
- Clear or yellow discharge from nose or eyes
- Painful ulcers on the tongue, palate, lips, or nose
Cats may also become lethargic, lose their appetite, run a fever, develop swollen lymph nodes, squint frequently, or show oral pain. Since there are multiple strains of FCV, some cats might experience pneumonia, joint pain, or even lameness.
3. Feline Panleukopenia (FPL) / Feline Distemper
This highly contagious viral disease attacks rapidly dividing cells—especially those in the intestines, bone marrow, and lymph nodes. While any cat can get sick from panleukopenia, kittens are at greatest risk. Symptoms often include:
- Depression and lethargy
- Loss of appetite
- High fever
- Vomiting and severe diarrhea
- Nasal discharge
- Dehydration; sometimes collapse
The virus spreads through direct contact with infected animals as well as contaminated surfaces like food bowls or water dishes. It moves fast—and without quick medical care—can be fatal. There aren't medications that kill this virus directly; treatment focuses on supportive care such as fluids and intensive nursing to help cats recover while their immune system fights off infection. Because panleukopenia weakens immunity so much, secondary bacterial infections are common.
The Importance of Vaccination for All Cats
You might think indoor-only cats are safe—but that's not quite true. The viruses covered by FVRCP can hitch a ride into your home on clothing, shoes, or everyday objects you bring inside. This makes vaccination crucial for every cat.
Vaccination Schedule & Booster Shots
Kittens should start their first round of FVRCP shots at six to eight weeks old. Boosters follow every three to four weeks until they're 16–20 weeks old. After this series wraps up, they get another booster one year later; then adults usually need boosters every three years.
- Kittens: Initial vaccine at 6–8 weeks old; boosters every 3–4 weeks until 16–20 weeks old.
- Adults: Booster one year after kitten series; then every three years.
- Cats with unknown history: May need to restart series for full protection.
This schedule helps prevent both individual illness and outbreaks among groups of cats.
Mild Side Effects & Rare Reactions
The vast majority of cats tolerate the FVRCP vaccine well—side effects are uncommon and usually mild: maybe a low-grade fever, brief lethargy, or minor swelling at the injection site that fades quickly. Some may sneeze or have a mild respiratory reaction for a short time afterward.
Seldomly—though it does happen—a cat might experience hives, swelling around the lips/eyes, itchiness, fever spikes, diarrhea or vomiting after vaccination. If you notice these signs or any trouble breathing post-shot, call your veterinarian right away just to be safe.
The Bottom Line: Why Immunization Matters
The diseases prevented by the FVRCP vaccine can be devastating—especially for young kittens and older pets whose immune systems can't fight as hard. Regular vet visits and sticking to recommended vaccination schedules give your cat its best shot at a long life free from these serious illnesses.





