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PetDosageChart

Atarax (Hydroxyzine) Dosage for Dogs

Antihistamine (first-generation) ⏱ Onset: 30-60 minutes ⏳ Duration: 8-12 hours

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. This information is sourced from veterinary drug references including Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

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Atarax Dosage Chart for Dogs by Weight

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Weight Low Dose Standard Dose Max Dose Frequency
5 lbs (2.3 kg) 2.5mg 4.5mg 4.5mg every 8-12 hours
10 lbs (4.5 kg) 4.5mg 9mg (10mg tablet) 9mg (10mg tablet) every 8-12 hours
15 lbs (6.8 kg) 7mg 13.5mg 13.5mg every 8-12 hours
20 lbs (9.1 kg) 9mg (10mg tablet) 18mg (2 × 10mg) 18mg (2 × 10mg) every 8-12 hours
25 lbs (11.3 kg) 11.5mg (10mg tablet) 22.5mg 22.5mg every 8-12 hours
30 lbs (13.6 kg) 13.5mg 27mg 27mg every 8-12 hours
40 lbs (18.1 kg) 18mg (2 × 10mg) 36mg 36mg every 8-12 hours
50 lbs (22.7 kg) 22.5mg 45.5mg 45.5mg every 8-12 hours
60 lbs (27.2 kg) 27mg 54.5mg 54.5mg every 8-12 hours
70 lbs (31.7 kg) 31.5mg (3 × 10mg) 63.5mg 63.5mg every 8-12 hours
80 lbs (36.3 kg) 36.5mg 72.5mg 72.5mg every 8-12 hours
90 lbs (40.8 kg) 41mg (4 × 10mg) 81.5mg (8 × 10mg) 81.5mg (8 × 10mg) every 8-12 hours
100 lbs (45.4 kg) 45.5mg 91mg (9 × 10mg) 91mg (9 × 10mg) every 8-12 hours
120 lbs (54.4 kg) 54.5mg 109mg (11 × 10mg) 109mg (11 × 10mg) every 8-12 hours
150 lbs (68 kg) 68mg (7 × 10mg) 136mg 136mg every 8-12 hours

What is Atarax (Hydroxyzine) used for in dogs?

allergies itching anxiety atopic dermatitis

How to give Atarax to your dog

Hydroxyzine can be given with or without food. It is often considered more effective than diphenhydramine (Benadryl) for dogs with atopic dermatitis. Give consistently for best allergy control. May cause drowsiness, especially in the first few days.

Available Forms

tablet, capsule, liquid

Give with Food?

Yes — give with food

Side effects of Atarax in dogs

Common side effects

drowsiness
dry mouth
decreased appetite
mild sedation

Serious side effects

  • excessive sedation
  • urinary retention
  • tremors
  • seizures (at very high doses)

When to call the vet

Call your vet immediately if your dog shows any of these signs:

  • Excessive sedation or inability to wake
  • Difficulty urinating
  • Tremors or seizures
  • Itching significantly worsens
  • Vomiting or diarrhea persists

Related Medications for Dogs

First-generation antihistamine

Chlor-Trimeton

Chlorpheniramine

For Allergies

View dosage chart
Antihistamine (second-generation)

Zyrtec

Cetirizine

For allergies

View dosage chart
Antihistamine (second-generation)

Claritin

Loratadine

For allergies

View dosage chart
Antihistamine

Benadryl

Diphenhydramine

For allergies

View dosage chart

Sources & References

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Hydroxyzine.

Frequently Asked Questions

Is hydroxyzine better than Benadryl for dogs?
Many veterinary dermatologists consider hydroxyzine more effective than Benadryl for managing allergic skin conditions in dogs. Hydroxyzine is more potent and may provide better itch relief. However, it requires a prescription, while Benadryl is available over-the-counter.
How much hydroxyzine can I give my dog?
The typical dose is 2 mg per kilogram of body weight, given every 8-12 hours. For example, a 25 lb (11 kg) dog would receive approximately 22 mg per dose. Your vet will determine the exact dose and frequency.
Does hydroxyzine make dogs sleepy?
Yes, drowsiness is the most common side effect of hydroxyzine, as it is a first-generation antihistamine. Most dogs develop tolerance to the sedative effects within a few days. The initial drowsiness often subsides with continued use.
Can I give my dog hydroxyzine every day?
Yes, hydroxyzine is commonly prescribed for daily use in dogs with chronic allergies or atopic dermatitis. Consistent daily dosing provides the best allergy control. Your vet may adjust the dose seasonally based on allergy severity.

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