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PetDosageChart

Atarax (Hydroxyzine) Dosage for Cats

Antihistamine (H1 Receptor Antagonist) ⏱ 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.

Dosage Calculator

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Atarax Dosage Chart for Cats by Weight

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Weight Low Dose Standard Dose Max Dose Frequency
3 lbs (1.4 kg) 1.5mg 2mg 3mg Every 8-12 hours
4 lbs (1.8 kg) 2mg 2.5mg 3.5mg Every 8-12 hours
5 lbs (2.3 kg) 2.5mg 3.5mg 4.5mg Every 8-12 hours
6 lbs (2.7 kg) 2.5mg 4mg 5.5mg Every 8-12 hours
7 lbs (3.2 kg) 3mg 5mg 6.5mg Every 8-12 hours
8 lbs (3.6 kg) 3.5mg 5.5mg 7mg Every 8-12 hours
9 lbs (4.1 kg) 4mg 6mg 8mg (10mg tablet) Every 8-12 hours
10 lbs (4.5 kg) 4.5mg 7mg 9mg (10mg tablet) Every 8-12 hours
12 lbs (5.4 kg) 5.5mg 8mg (10mg tablet) 11mg (10mg tablet) Every 8-12 hours
14 lbs (6.3 kg) 6.5mg 9.5mg (10mg tablet) 12.5mg Every 8-12 hours
16 lbs (7.3 kg) 7.5mg (10mg tablet) 11mg (10mg tablet) 14.5mg Every 8-12 hours
18 lbs (8.2 kg) 8mg (10mg tablet) 12.5mg 16.5mg Every 8-12 hours
20 lbs (9.1 kg) 9mg (10mg tablet) 13.5mg 18mg (2 × 10mg) Every 8-12 hours
25 lbs (11.3 kg) 11.5mg (10mg tablet) 17mg 22.5mg Every 8-12 hours

What is Atarax (Hydroxyzine) used for in cats?

Allergic dermatitis and itching Atopic dermatitis Urticaria (hives) Mild anxiety Mast cell tumor management (adjunctive)

How to give Atarax to your cat

Hydroxyzine tablets or capsules can be given whole, hidden in a pill pocket or small piece of cheese or deli meat. For cats that refuse pills, the tablet can be crushed and mixed into a small amount of strong-flavored wet food, though this may reduce palatability. A compounded flavored liquid is often the easiest option for finicky cats. Use a pill gun to place the pill at the back of the tongue if giving directly, then offer a treat or syringe a small amount of water to ensure it is swallowed. Give with food to minimize stomach upset.

Available Forms

Tablet, Capsule, Oral suspension, Compounded liquid

Give with Food?

Yes — give with food

Side effects of Atarax in cats

Common side effects

Sedation and drowsiness
Dry mouth
Decreased appetite
Paradoxical excitement or hyperactivity in some cats

Serious side effects

  • Severe paradoxical agitation
  • Urinary retention
  • Cardiac arrhythmias (rare, at high doses)
  • Seizures (very rare)

When to call the vet

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

  • Severe hyperactivity or agitation (paradoxical reaction)
  • Difficulty urinating or no urine output
  • Rapid or irregular heartbeat
  • Excessive sedation or inability to wake
  • Facial swelling or difficulty breathing (allergic reaction to the medication)

Frequently Asked Questions

Can hydroxyzine make my cat hyper instead of sleepy?
Yes, some cats experience a paradoxical reaction to hydroxyzine where they become more agitated and hyperactive instead of sedated. This is more common in cats than in dogs. If your cat becomes unusually restless, vocal, or aggressive after taking hydroxyzine, discontinue the medication and contact your vet. An alternative antihistamine may be better suited for your cat.
Is hydroxyzine better than Benadryl for cats?
Hydroxyzine is often considered more effective than diphenhydramine (Benadryl) for allergic conditions in cats because it has both antihistamine and mild anti-anxiety properties. It also has some mast cell-stabilizing activity. However, response varies between individual cats—some do better on one antihistamine versus another. Your vet can help determine which is the best choice for your cat.
How long does it take for hydroxyzine to help my cat's itching?
Hydroxyzine typically starts working within 30-60 minutes of oral administration. However, for chronic allergic conditions, it may take several days of consistent dosing to see the full benefit. Antihistamines work best as preventatives, so giving them before expected allergen exposure is ideal. If you see no improvement after 2 weeks of regular dosing, consult your vet about alternatives.
Can I give my cat hydroxyzine every day?
Yes, hydroxyzine can be given daily for chronic allergy management in cats. It is generally safe for long-term use when dosed appropriately. Your vet may recommend giving it every 8-12 hours depending on symptom severity. Periodic check-ups are advisable during long-term use to monitor for any side effects.
What is the correct hydroxyzine dose for a cat?
The typical hydroxyzine dose for cats is 1-2 mg/kg given every 8-12 hours. For an average 4 kg cat, this is approximately 5-10 mg per dose. Always start at the lower end to assess your cat's response, as some cats are more sensitive than others. Your veterinarian will determine the ideal dose based on your cat's specific condition and weight.