Essential amino acid that competes with arginine for absorption and incorporation into proteins. Feline herpesvirus (FHV-1) is arginine-dependent — lysine supplementation may reduce arginine availability, theoretically suppressing viral replication. Evidence is controversial.
At a glance
Class
Essential Amino Acid / Antiviral Adjunct
Storage
Store at room temperature
Dosing
Canine herpesvirus does not have the same arginine dependency
Widely used for FHV-1 management, but recent evidence questions efficacy
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
FHV-1 flare frequencyClinical upper respiratory signs
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 Lysine (L-Lysine)?
Lysine (L-Lysine) is a essential amino acid / antiviral adjunct used in pets. Essential amino acid that competes with arginine for absorption and incorporation into proteins. Feline herpesvirus (FHV-1) is arginine-dependent — lysine supplementation may reduce arginine availability, theoretically suppressing viral replication. Evidence is controversial.
›What is Lysine (L-Lysine) used for in pets?
Lysine (L-Lysine) is used in veterinary medicine for: Canine herpesvirus does not have the same arginine dependency; Widely used for FHV-1 management, but recent evidence questions efficacy.
›What is the Lysine (L-Lysine) dose for dogs?
For dogs, Lysine (L-Lysine) is typically dosed as follows — Canine herpesvirus does not have the same arginine dependency: undefined undefined PO N/A. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Lysine (L-Lysine) dose for cats?
For cats, Lysine (L-Lysine) is typically dosed as follows — Widely used for FHV-1 management, but recent evidence questions efficacy: 250–500 mg/cat PO q12–24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Lysine (L-Lysine) need a prescription?
Lysine (L-Lysine) is available over the counter. Even so, you should consult your veterinarian before giving any medication to your pet.
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