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Cetirizine

Second-generation antihistamine (H1 receptor antagonist) — non-sedating
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
4 available
Formulations
3

Mechanism of action

Selective peripheral H1 receptor antagonist; active metabolite of hydroxyzine with minimal CNS penetration, reducing pruritus without significant sedation

At a glance

Class
Second-generation antihistamine (H1 receptor antagonist) — non-sedating
Schedule
OTC
Storage
Store below 25°C

Dosing

🐕

Dog

Allergic pruritus / atopic dermatitis (adjunct)
Dose
1–2 mg/kg
Route
PO
Frequency
SID-BID
Max dose
20 mg/dose; 40 mg/day
Duration: Long-term as needed
🐈

Cat

Allergic pruritus
Dose
2.5–5 mg/cat
Route
PO
Frequency
SID
Max dose
5 mg
Duration: Long-term as needed
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

💊

Tablet — 1

Strength
10mg
Available in India
🧴

Syrup — 1

Strength
5mg/5mL
Available in India
💊

Drops — 1

Strength
10mg/mL
Available in India

Storage

Store below 25°C

Safety

Use with caution

  • Severe renal impairment
    Renally excreted — reduce dose or frequency in renal failure
  • Concurrent CNS depressants
    Minimal but possible additive sedation
  • Hepatic impairment
    Partially hepatically metabolised

Adverse effects

Common
Mild sedation (less than first-generation)
Dry mouth
Serious
Urinary retention (rare)
Paradoxical excitation (rare)

Monitoring parameters

Pruritus scoreClinical response
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

International

Zyrtec
Johnson & Johnson

India

Cetzine
Alkem
Alerid
Cipla
Okacet
Lupin

FAQs

Frequently asked questions

What is Cetirizine?
Cetirizine is a second-generation antihistamine (h1 receptor antagonist) — non-sedating used in pets. Selective peripheral H1 receptor antagonist; active metabolite of hydroxyzine with minimal CNS penetration, reducing pruritus without significant sedation
What is Cetirizine used for in pets?
Cetirizine is used in veterinary medicine for: Allergic pruritus / atopic dermatitis (adjunct); Allergic pruritus.
What is the Cetirizine dose for dogs?
For dogs, Cetirizine is typically dosed as follows — Allergic pruritus / atopic dermatitis (adjunct): 1–2 mg/kg PO SID-BID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Cetirizine dose for cats?
For cats, Cetirizine is typically dosed as follows — Allergic pruritus: 2.5–5 mg/cat PO SID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What are the side effects of Cetirizine?
Common: Mild sedation (less than first-generation), Dry mouth. Serious (call your vet immediately): Urinary retention (rare), Paradoxical excitation (rare).
Does Cetirizine need a prescription?
Cetirizine 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

Related medicines

Other medicines in the same class (Second-generation antihistamine).

Fexofenadine
Non-sedating selective H1-receptor antagonist that does not cross the blood-brain barrier significantly. No anticholinergic activity. No cardiac QT prolongation.
dogcat
Loratadine
Non-sedating selective peripheral H1-receptor antagonist that does not significantly cross the blood-brain barrier. No anticholinergic activity. Active metabolite desloratadine also contributes to antihistamine effect.
dogcat
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