20 lb dog: Benadryl amounts by product
| Product | Usual dose for 20 lb |
|---|---|
| Diphenhydramine in mg | 20 mg (range 18.1 to 36.3 mg) |
| Adult tablet, 25 mg | ¾ tablet |
| Children's chewable, 12.5 mg | 1½ chewables |
| Children's liquid, 12.5 mg per 5 mL | 8 mL |
20 lb is a small dog, about the size of a Pug, Frenchie or small Beagle. A 12.5 mg children’s chewable or the liquid makes it easier to get close to the right dose. Just check the label for xylitol first.
How often can a 20 lb dog have Benadryl?
Every 8 to 12 hours, so no more than 3 doses in 24 hours. If one dose doesn't seem to help, don't double the next one. Call your vet instead, because the problem may need a different medicine.
Watch for these side effects
Expect some sleepiness. Call your vet if your dog becomes very agitated, pants hard, has a racing heart, can't pee, or vomits repeatedly. Wide pupils, tremors or seizures can signal an overdose. If you see them, call ASPCA Animal Poison Control on (888) 426-4435 or go to an emergency clinic.
Always confirm the dose with your own vet, especially if your dog has a health condition or takes other medicines.
Frequently asked questions
How many mg of Benadryl can a 20 lb dog have?
About 20 mg per dose is the usual starting dose (roughly 1 mg per pound). The vet range for a 20 lb dog is 18.1 to 36.3 mg, no more often than every 8 hours.
How many 25 mg Benadryl tablets for a 20 lb dog?
About ¾ tablet, which is 18.8 mg.
How much liquid Benadryl for a 20 lb dog?
About 8 mL of children's diphenhydramine liquid (12.5 mg per 5 mL). Use an oral syringe and make sure the product contains no xylitol.