💊 Cat Benadryl Dosage Calculator
Calculate typical feline diphenhydramine doses using weight and tablet strength. Veterinary confirmation required.
Many pediatric liquids contain 12.5 mg per teaspoon (5 mL). Avoid products sweetened with xylitol.
Monitor for excessive drowsiness or gastrointestinal upset.
Important!
Benadryl can interact with other medications and cause sedation. Never administer without veterinary guidance, especially to cats with heart or thyroid disease.
How to Use This Calculator
Weigh your cat
Use the most recent veterinary weight or weigh at home for accurate dosing.
Enter product strength
Check packaging for mg per tablet or per mL/teaspoon for liquids.
Confirm with your veterinarian
Bring the calculated dose to your vet before administering the medication.
Formula
Dose (mg) = Weightkg × 1 mg/kg
Tablets (or mL) = Dose ÷ Strength
Typical feline doses range from 1–2 mg/kg every 8–12 hours. Your veterinarian may adjust based on clinical signs and concurrent medications.
Full Description
Diphenhydramine (Benadryl) is occasionally used to manage mild allergic reactions or motion sickness in cats. Because cats are sensitive to sedatives and bitter flavors, dosing accuracy and veterinary approval are essential.
Watch for adverse reactions such as vomiting, diarrhea, or paradoxical excitement. Emergency care is required for severe swelling or breathing difficulty.
Frequently Asked Questions
Can cats take children’s liquid Benadryl?
Only if it contains plain diphenhydramine and no xylitol or alcohol. Always verify with your veterinarian.
What if my cat spits it out?
Do not repeat the dose without guidance. Ask your vet about compounded flavors or injectable alternatives.
How quickly does Benadryl work?
Effects usually begin within 30 minutes and last 8–12 hours, depending on metabolism.
Is Benadryl safe for cats with heart disease?
Use caution. Underlying conditions may contraindicate antihistamines. Always consult your veterinarian first.