Hydroxyzine Dosage for Dogs: What Pet Owners Should Know
Hydroxyzine is a first-generation prescription antihistamine frequently used in veterinary medicine to treat a variety of allergic and anxiety-related conditions in dogs. Though originally developed for humans, veterinarians commonly prescribe it off-label for canine patients.
Common Uses of Hydroxyzine in Dogs
Hydroxyzine serves multiple purposes in canine medicine, including:
- Management of allergic reactions such as itching, hives, and rashes
 - Treatment of atopic dermatitis and other chronic skin diseases
 - Relief from bee stings and insect bites
 - Support during vaccine reactions
 - Control of mild nausea or motion sickness
 - Tranquilization and anxiety reduction in pre-operative settings or mild behavioral issues
 
Recommended Dosage
The typical dosage of hydroxyzine for dogs is 1 to 2 mg per pound of body weight (approximately 0.5 to 2 mg per kilogram), administered by mouth every 6 to 12 hours. This range may vary depending on:
- Dog’s weight
 - Overall health status
 - Condition being treated
 - Response to initial doses
 
Hydroxyzine can be administered with or without food. Providing it with food may reduce the likelihood of gastrointestinal upset.
Forms of Administration
This medication is available in several forms:
- Tablets
 - Capsules
 - Oral liquids
 
Liquid forms must be shaken well before dosing, and it is vital to use accurate measuring tools such as a syringe rather than household spoons.
If You Miss a Dose
If a dose is missed, give it as soon as you remember unless the next dose is nearly due. In that case, skip the missed dose and continue on schedule. Never double up on doses.
Onset and Duration
Hydroxyzine generally takes effect within 1 to 2 hours and its effects last for around 6 to 12 hours, depending on the dog’s metabolism and health conditions.
Effectiveness and Limitations
The effectiveness of hydroxyzine in dogs is considered moderate. While it can provide significant relief for many, especially in acute allergic reactions, dogs with more persistent conditions might not respond as well. For these cases, veterinarians may recommend alternatives such as:
- Apoquel
 - Cytopoint
 - Immunotherapy
 - Corticosteroids
 
Possible Side Effects
As with any medication, hydroxyzine carries potential side effects. The most common include:
- Drowsiness or sedation
 - Dry mouth
 - Increased thirst
 - Constipation
 - Decreased appetite
 - Digestive upset (vomiting or diarrhea)
 - Hyperexcitability or tremors (rare)
 - Seizures or collapse (very rare)
 
Serious symptoms such as difficulty urinating or excessive lethargy require immediate veterinary attention.
Precautions and Contraindications
Hydroxyzine should be used with caution in dogs with:
- Glaucoma
 - Heart or kidney disease
 - Prostate enlargement
 - Seizure disorders
 
It is not recommended for:
- Pregnant or lactating dogs
 - Puppies and geriatric dogs
 - Working or service animals due to sedative effects
 
Drug Interactions
Hydroxyzine can interact negatively with other medications, especially:
- Central nervous system depressants like diazepam or sedatives
 - Anticholinergic medications (e.g., atropine)
 - Epinephrine
 
Always inform your veterinarian of all medications and supplements your dog is receiving.
Signs of Overdose
Symptoms of overdose may include:
- Extreme sleepiness or agitation
 - Loss of coordination
 - High body temperature
 - Seizures
 - Collapse
 
Seek emergency veterinary help immediately if overdose is suspected.
Storage Instructions
- Store at room temperature
 - Keep away from moisture and light
 - Follow all veterinary and pharmacist storage guidelines
 
Final Thoughts
Hydroxyzine is a versatile medication that can help manage a range of allergic and anxiety-related conditions in dogs when used correctly. However, the correct dosage and regular monitoring are key to ensuring safety and efficacy. Pet owners should never administer hydroxyzine—or any medication—without specific veterinary guidance.
Always consult your veterinarian before starting or adjusting your pet’s treatment regimen.





