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Hydroxychloroquine

Prescription
Antimalarial / Immunomodulator
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
1 available
Formulations
1

Mechanism of action

Accumulates in lysosomes, raising pH and inhibiting antigen processing, Toll-like receptor signaling, and cytokine production (TNF-α, IL-1, IL-6). Anti-inflammatory and immunomodulatory without significant immunosuppression. Also has antithrombotic effects.

At a glance

Class
Antimalarial / Immunomodulator
Schedule
Prescription
Storage
Store at room temperature below 30°C

Dosing

🐕

Dog

Used for immune-mediated polyarthritis, discoid lupus erythematosus, and systemi
Dose
5–10 mg/kg
Route
PO
Frequency
q24h
🐈

Cat

Very limited feline data
Dose
Route
PO
Frequency
N/A
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 →

Formulations

💊

Other — 1

Strength

Storage

Store at room temperature below 30°C

Safety

Monitoring parameters

Fundoscopic/retinal exam q6–12 monthsHepatic enzymesECG (QTc)Clinical response at 8–12 weeks
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.

Brands

Other markets

Plaquenil

FAQs

Frequently asked questions

What is Hydroxychloroquine?
Hydroxychloroquine is a antimalarial / immunomodulator used in pets. Accumulates in lysosomes, raising pH and inhibiting antigen processing, Toll-like receptor signaling, and cytokine production (TNF-α, IL-1, IL-6). Anti-inflammatory and immunomodulatory without significant immunosuppression. Also has antithrombotic effects.
What is Hydroxychloroquine used for in pets?
Hydroxychloroquine is used in veterinary medicine for: Used for immune-mediated polyarthritis, discoid lupus erythematosus, and systemi; Very limited feline data.
What is the Hydroxychloroquine dose for dogs?
For dogs, Hydroxychloroquine is typically dosed as follows — Used for immune-mediated polyarthritis, discoid lupus erythematosus, and systemi: 5–10 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Hydroxychloroquine dose for cats?
For cats, Hydroxychloroquine is typically dosed as follows — Very limited feline data: undefined undefined PO N/A. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
Does Hydroxychloroquine need a prescription?
Yes. Hydroxychloroquine 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
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