Cetirizine

What is this medication for?

• Adjunct for pruritic/allergic conditions (atopic dermatitis, chronic rhinosinusitis)

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• Never dispense the pseudoephedrine-combination product (Zyrtec-D) — always confirm which formulation a client already has at home before recommending an OTC purchase.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Vomiting, hypersalivation (Reported)
• Drowsiness (Higher-dose, small dogs)
• Well tolerated overall

Worth a phone call to your veterinarian

• Any new symptom that worries you.

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Hypersensitivity to cetirizine/hydroxyzine
• has or has had: Combination products containing pseudoephedrine (Zyrtec-D) are not appropriate for dogs/cats — never dispense these

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • CNS depressants

Storage and handling

Tablets 20–25°C. Oral syrup: room temperature or refrigerated.

Good to know

• Comparatively low-drowsiness option relative to diphenhydramine — useful when drowsiness is undesirable (e.g., working/active dogs), but efficacy data for itching control is modest and inconsistent.
• Never dispense the pseudoephedrine-combination product (Zyrtec-D) — always confirm which formulation a client already has at home before recommending an OTC purchase.