Feline Herpesvirus
No, I am not talking about cold sores, trips to Vegas, or people who study reptiles and amphibians. This blog post is about one of the most common reasons feline owners bring their cat to the vet: Feline Viral Rhinotracheitis (FVR) or Feline Herpesvirus.
The Goal: To help you identify symptoms and prevent flare-ups.
1. What is it?
"Herpes is Forever." As your sex ed teacher probably told you, herpes is for life. While they probably weren't talking about your cat, the rule still applies.
Transmission: It is spread through contact or contaminated surfaces.
The Victim: Most often, we see this in young kittens or immunocompromised cats.
2. Clinical Signs (The "Goopy" Phase)
While we often don't see the virus itself, we see the mess it leaves behind (usually secondary bacterial infections).
The Symptoms: Sneezing, runny nose, goopy eyes, and squinting.
The Severe Cases: Occasionally, it can be much worse. You can read about my own cat, Stevie, who lost both eyes to suspected severe FVR.
3. Diagnostics: How do we know?
The History (The "Honest Fight") The best diagnostic tool is often just talking to you. FVR mimics many other diseases, but your answers help us narrow it down.
Tip: Tell us everything. Did you hire a pet sitter? Adopt a new pet? Give over-the-counter meds?
Note: Your vet might fight you if you gave human meds, but if you are honest about it, we will try to make it a fair fight.
The Trigger: We typically see flare-ups after a stress event: moving, a new pet, or a flea infestation.
Stevie. Our rescue cat that lost both eyes to severe herpes virus
The Science
PCR Test: There is a highly accurate DNA test (high sensitivity and specificity for you stats nerds) if we need to confirm it.
4. Treatment: Good News vs. Bad News
The Good News: The symptoms usually resolve quickly with help.
Antibiotics: Used to clear up the secondary bacterial infections (the snot and goop).
L-Lysine: An inexpensive amino acid supplement that may help prevent future flare-ups. This is still just a supplement and may or may not help. Current studies are mixed on its efficacy, but it is safe and often worth a try.
The Bad News: It is still herpes.
Resolution: In healthy cats, it resolves on its own. In sick cats, we have to treat the underlying cause (spoiler: it's almost always fleas).
Antivirals: For severe cases or frequent reoccurrences, we may prescribe antiviral medications.
5. Prevention: The Vaccine
The FVRCP (The "Distemper" Shot) This vaccine includes protection against FVR.
The Reality: It does not prevent infection entirely, but it helps the immune system fight it off much faster.
The Schedule: We recommend this every 1–3 years, even for indoor cats.
The "Relief Work" Trick: Giving this vaccine intranasally (up the nose) can stimulate a local immune response for cats that are sneezing like crazy. Works about half of the time in my experience.
Summary:
If you do these four things, 92% of my job is done:
Vaccinate (FVRCP & Rabies).
Prevent (Fleas, Ticks, and Heartworm).
Feed (Quality diets like Purina, Hills, or Royal Canin).
Cut (Spay/Neuter at 5–6 months).
Hopefully, this information sticks with you forever, like herpes.
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