For the Purrbabies

It’s incredibly common for dogs to have allergies, leaving pet owners looking for a solution with the least potential side effects. The good news is the same Benadryl that’s in your medicine cabinet can work wonders for canines too.
Although it’s not yet been approved by the FDA for use in animals, it’s fairly common for veterinarians to suggest giving your dog a dose of over-the-counter medication like Benadryl to counteract the symptoms of seasonal allergies, environmental allergies, food allergies, integumentary diseases (skin-related conditions), and one-off allergic or histamine reactions.
Although there are factors like pre-existing conditions and breed type that may come into play (consult with your vet), the suggested dosage is typically 1-2 mg of Benadryl (Trusted Source) for every pound of body weight. You can start by giving your dog the lowest dosage up to twice daily, working up to the normal dose as you see that your dog can tolerate it.
So, if you have a 25-pound dog, start with the low-end dose of 25 mg and observe the results. If you don’t see an obvious difference in the next 30 to 60 minutes, try the high-end dose of 50 mg at the next interval. The recommended dosage may vary depending on a range of other factors, including your dog’s age and any other previous health conditions they may have.
Always start with the low-end dosage. Diphenhydramine is an older generation antihistamine so a side effect is drowsiness. Most of my patients are like zombies when they get the high end of the dose range!
Erica Irish, DVM
Give your dog the Benadryl tablets, not liquid Benadryl caplets. Benadryl comes in 25 mg tablets, which makes it easier to get closer to the exact dosage you need when preparing them for your pet, as opposed to the liquid caps. Plus, they’re easier to break in half for smaller dogs.
Like mentioned above, it’s recommended to give your dog 1-2 mg of Benadryl per pound of body weight (Trusted Source) (or 2-4 mg per kilogram). This amount can generally be given two to three times per day, depending on any medical conditions your dog might have.
We do want to note that not all Benadryl products are created equal. Time-release capsules may not give the correct dosage to your dog at any given time and can cause overdoses. Additionally, liquid Benadryl can be formulated with sodium or alcohol, which can cause other problems for your pet.
With this in mind, many pet parents choose diphenhydramine in liquid form, capsule form, or “chew” form if the pet has difficulty with medication delivery methods. Children’s Benadryl tablets might also be effective and can be given at the discretion of your vet.
The reasons you’d consider giving your dog a dose of Benadryl are similar to the reasons you’d give it to a person:
Since Benadryl is an antihistamine, it works by blocking the naturally occurring histamines in your dog’s body and some of the symptoms it causes. (Benadryl is the brand name for diphenhydramine HCl, which is the active ingredient.)
Keep in mind that when taken by mouth, it takes about 15 to 30 minutes to begin working. If your dog is experiencing some extreme sneezing or itching, it will take a bit of time before they’ll get relief. Don’t rush to give your dog a larger dose until sufficient time has passed for the Benadryl to start working. If you notice that your dog is having difficulty breathing or worsens, please go to the vet for further care.
As with any other drug, there can be side effects. Benadryl can have side effects in humans, not just dogs, so before giving your pup a dose, consider what some of the negative effects can be:
These are signs that Benadryl is probably not the best solution for your dog. Additionally, make sure to check with your vet before giving your dog any Benadryl if they have pre-existing conditions like:
Benadryl can cause adverse reactions in dogs that have these conditions and those that are similar. One final thing to note is that if your dog is pregnant, it’s unlikely your veterinarian will give you the go-ahead to give them Benadryl at all.
If your dog struggles with allergy-related conditions like atopic dermatitis, consider a few of these OTC alternatives that can help make a small dent in your dog’s symptoms.
Never use Benadryl to treat motion sickness and travel anxiety in dogs. Yes, it can make your dog sleep, but the drug is not intended for this use.
We’ve all been there — it’s time for a car ride and your dog won’t stop fussing in the back seat. Maybe it’s their first time flying in a carrier and they’re having trouble getting comfortable or being still. Just know that Benadryl won’t address the root problems of motion sickness or anxiety.
Instead of drugging your dog to sleep, we recommend Cerenia (maropitant) or Dramamine for motion sickness. Some dog owners swear by CBD, though we’re still waiting for science to catch up. Ask your vet about anxiety treatments before your next road trip. 🚙
Similar to side effects, the signs of a severe allergic reaction to Benadryl will look like the following:
🚨 If you suspect your dog is having an allergic reaction to Benadryl, contact your vet or bring them to an emergency veterinarian hospital right away.
Although it’s unlikely your dog will experience adverse effects from Benadryl, it’s important to be aware that they are a possibility. Since there are over-the-counter alternatives, if your dog’s symptoms are relatively mild, you may be better off skipping Benadryl altogether.
If your pet’s suffering from the springtime snuffles, it’s likely more than okay to give them a small amount of Benadryl for relief on occasion. However, we always recommend consulting with your veterinarian before giving your dog a dose of anything new.
The average recommendation is 2-4 milligrams of Benadryl per kilogram of dog. Your vet can help you decide the best method of delivery based on your dog’s personal preferences and needs. For example: Some dogs might prefer taking their medicine in chew form rather than capsules.
Yes, you can give your dog Benadryl for itchy or inflamed paws. You also might want to follow up with a vet to determine any underlying causes of irritation that could be making the licking worse.
The answer depends on the type of Benadryl being given. Chews can be given on their own, while capsules are best given in bread, peanut butter, a bit of lunch meat, or your dog’s favorite treat. If you’re not sure how to best get the medicine into your dog, your vet can help by offering pet-safe alternatives that work.
👉 You can also try to soothe your pup’s allergies with Ready Pet Go’s Allergy Dog Supplement for doggies, made with natural ingredients.