Prodrug converted to penciclovir, which is phosphorylated by viral thymidine kinase and inhibits viral DNA polymerase, blocking herpesvirus DNA replication. Selective for virus-infected cells.
At a glance
Class
Antiviral (Nucleoside Analog)
Storage
Store at room temperature below 30°C
Dosing
Dogs rarely need antiviral therapy for herpesvirus
Drug of choice for feline herpesvirus-1 (FHV-1) — conjunctivitis, keratitis, URI
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
Find a vet near you →Safety
Clinical responseRenal function with prolonged therapyOphthalmologic exam
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
Find a vet near you →Interactions
No documented interactions.
FAQs
Frequently asked questions
›What is Famciclovir?
Famciclovir is a antiviral (nucleoside analog) used in pets. Prodrug converted to penciclovir, which is phosphorylated by viral thymidine kinase and inhibits viral DNA polymerase, blocking herpesvirus DNA replication. Selective for virus-infected cells.
›What is Famciclovir used for in pets?
Famciclovir is used in veterinary medicine for: Dogs rarely need antiviral therapy for herpesvirus; Drug of choice for feline herpesvirus-1 (FHV-1) — conjunctivitis, keratitis, URI.
›What is the Famciclovir dose for dogs?
For dogs, Famciclovir is typically dosed as follows — Dogs rarely need antiviral therapy for herpesvirus: undefined undefined PO N/A. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Famciclovir dose for cats?
For cats, Famciclovir is typically dosed as follows — Drug of choice for feline herpesvirus-1 (FHV-1) — conjunctivitis, keratitis, URI: 40–90 mg/kg PO q8h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Famciclovir need a prescription?
Yes. Famciclovir is a prescription medication and should only be administered under veterinary supervision.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
Find a vet near you →References
References
The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.
Textbooks & handbooks — 5
- Plumb's Veterinary Drug Handbook
- Withrow & MacEwen's Small Animal Clinical Oncology
- Merck Veterinary Manual
- NRC Nutrient Requirements of Dogs and Cats
- Veterinary Pharmacology and Therapeutics (Riviere & Papich)
Clinical guidelines & consensus — 4
- ASPCA Animal Poison Control Center Guidelines
- AAHA Diabetes Management Guidelines
- ASPCA Poison Control Guidelines
- RECOVER CPR Guidelines
Journals & peer-reviewed studies — 2
- EPIC Study (J Vet Intern Med 2016)
- JVIM FAT CAT Study
Regulatory & approvals — 1
- CDSCO Veterinary Drug Approval Registry (1969–2026)
Databases — 1
- Washington State University VCPL MDR1 Database