Hydroxyzine Dosage Calculator for Cats
Dose ranges on this page are published veterinary references for education only. Your veterinarian's prescribed dose always wins. When in doubt, call your vet first.
Hydroxyzine is prescribed for cats with allergic skin conditions such as miliary dermatitis, symmetrical alopecia of allergic origin, and eosinophilic granuloma complex. Published references list 5–10 mg per cat, given every 8–12 hours.
Because dosing is per-cat rather than strictly by weight — and because contraindications matter — use the calculator below only as a reference alongside your veterinarian's prescription.
Dose calculator
Dosage chart by weight
| Cat weight | Dose range per dose |
|---|---|
| 5 lb | 5–10 mg (per cat) |
| 8 lb | 5–10 mg (per cat) |
| 10 lb | 5–10 mg (per cat) |
| 12 lb | 5–10 mg (per cat) |
| 15 lb | 5–10 mg (per cat) |
| 18 lb | 5–10 mg (per cat) |
| 20 lb | 5–10 mg (per cat) |
Chart uses the same conservative range as the calculator (5–10 mg per cat). Always confirm with your veterinarian.
Common formulations
- Tablets — 10 mg tablets
10 mg is the standard feline tablet size; 25 mg tablets must be split per vet instructions
Use the calculator above to convert any of these sizes into an amount for your pet's weight.
How often to give it
Every 8–12 hours. 5–10 mg per cat.
Common veterinary uses
- Miliary dermatitis
- Symmetrical alopecia of allergic origin
- Eosinophilic granuloma complex
- Allergic skin disease (vet-directed)
Safety warnings
Possible side effects
- Sedation / drowsiness
- Dry mouth
- Increased thirst (reported in cats)
- Behavioral changes (rare)
- Prescription-only — never use leftover human hydroxyzine for your cat.
- Watch for urinary difficulty — cats are prone to urinary issues and this drug can worsen them.
Do not use (or ask your vet first)
- Cats with glaucoma
- Cats with urinary obstruction
- Cats with heart disease
- Pregnant or nursing cats
When to see a veterinarian
- Straining to urinate or inability to urinate — this is an emergency in cats
- Extreme lethargy or unresponsiveness
- Vomiting or complete appetite loss
- Skin condition worsens or does not improve
Frequently asked questions
How much hydroxyzine can I give my cat?
Published references list 5–10 mg per cat every 8–12 hours. It is prescription-only, so your veterinarian sets the exact dose for your cat's condition.
Can I split a 25 mg hydroxyzine tablet for my cat?
Only exactly as your veterinarian instructs. Tablet splitting must be accurate at these small doses — ask your vet or pharmacist about the safest approach.
Why does my cat drink more on hydroxyzine?
Increased thirst is a reported side effect in cats, related to the drug's anticholinergic effects (dry mouth). Mention it to your vet, especially if excessive.
How long until hydroxyzine helps my cat's itching?
Some relief within hours of the first dose is typical, but several days of consistent treatment are usually needed for full effect in chronic skin conditions.
Sources
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Dose ranges on this page are published veterinary references for education only. Your veterinarian's prescribed dose always wins. When in doubt, call your vet first.