Benadryl or Diphenhydramine is typically thought to be a fast-acting medication for dogs. You can expect it to take effect in 1 to 2 hours but often times it will begin to work in under an hour.
How long does it take for Benadryl to make a dog sleepy?
It will usually take 30 minutes for Benadryl to take full effect, and you want your pup calm and anxious-free. In terms of what form of Benadryl, that's entirely up to your vet. It doesn't really matter if you use the brand name medication or not.
How do dogs act after taking Benadryl?
Dr. Selmer: The most common side effects of Benadryl are lethargy, dry mouth and urine retention. Diarrhea, vomiting and decreased appetite are possible, but not common. There is no evidence that Benadryl will cause fear in dogs.
How much Benadryl will calm a dog?
According to the Merck Veterinary Manual, the safe dosage is 2-4 milligrams of medication per kilogram of weight, or 0.9 to 1.8 milligrams per pound. This amount can be administered two to three times daily, depending on your dog's symptoms.
More useful articles on a similar topic 👇
How can I sedate my dog so I can cut his nails?What can I give my dog to relax before grooming?