Benedryl is an over-the-counter human medication you can use for dogs with an allergic reaction, such as from a bee sting. Benedryl, or generic diphenhydramine, is an antihistamine approved for people.
Benedryl is not FDA-approved for use in dogs, but it is commonly used off label. Benedryl can be purchased as 25-milligram (mg) tablets and 50-milligram “extra strength” tablets. You must be certain which Benedryl you have before giving it to your dogs. Most veterinary dosages are based on the 25-mg tablet.
In general, Benedryl doses for dogs—provided the dog is not vomiting or showing signs of diarrhea, weakness, or collapse—is approximately 1 to 2 mg of diphenhydramine per pound of body weight. That means a full 25-mg tablet is appropriate for a dog weighing 14 to 28 lbs. PreventiveVet has a clickable dosage chart. Just enter your dog’s weight, and it tells you how much diphenhydramine you can give the dog, based on 25 mg tablets.
Warning: If using any human diphenhydramine or Benadryl product, check how much diphenhydramine it contains and all other ingredients. Some products contain decongestants, which are dangerous for dogs. In addition, products containing alcohol or xylitol can harm or kill your dog.
While Benedryl often makes people drowsy, it has less of an effect on dogs. Still, it can reduce anxiety for some dogs and may help with nausea, such as car sickness. Be forewarned, however, that some dogs become anxious and hyper from Benedryl. If you’re looking for anti-anxiety meds for your dog, talk with your veterinarian.
Benedryl helps manage mild symptoms of seasonal allergies. For dogs, that often means itching and/or hives. You may see the dog rubbing his face, ears, and eyes, and maybe sneezing. Benedryl helps relieve inflammation and reduce swelling.
Always check with your veterinarian before giving your dog this medication, as it may not be appropriate for your individual dog based on your dog’s health, other medications, and what you think you’re treating. Include Benedryl in your pet first-aid kit but be proactive and get the specific dose for your dog from your vet ahead of time and put it with the drug.