How Much Benadryl Can You Give a Dog?

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What is Benadryl?

Benadryl is one of many brand names for the antihistamine diphenhydramine. Antihistamines like this one are used to relieve symptoms of allergies, common colds and more. Though made for humans, it’s also often recommended by DVMs to treat dogs. Some forms of Benadryl include:

• Children’s Benadryl (liquid Benadryl)
• Benadryl tablets
• Topical benadryl

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Uses of Benadryl for dogs

When it comes to dogs, veterinarians will most likely recommend Benadryl in cases of allergies. Other uses for Benadryl include managing symptoms of anxiety (acting as a mild sedative) and even motion sickness when a dog is traveling.

Allergies

Benadryl is often used to treat a dog’s symptoms when they are experiencing an allergic reaction. The three types of allergies dogs experience the most are environmental allergies (also known as seasonal allergies), atopic dermatitis and food allergies. Veterinarians might recommend Benadryl to treat mild allergy cases. However, severe allergic reactions will require a visit to the vet or the animal hospital.

Some signs and symptoms of allergies in dogs include the following:

• Sneezing
• Hives
• Insect bites
• Runny nose
• Watery eyes
• Itchy skin
• Skin irritation
• Difficulty breathing
• Ear infections
• Hair loss

Anxiety

In cases of dogs with anxiety, a vet might recommend Benadryl. However, it’s important to note that the medication may not be successful in lowering a dog’s anxiety. While some dogs may experience a little sedation or drowsiness under its effects, others may become even more anxious or hyperactive as it can increase their heart rates.

Some sources of anxiety for dogs include:

• Fireworks
• Traveling
• Thunderstorms
• Sudden change of environment

Benadryl dosage for dogs

The dosage of Benadryl you can give to your dog will depend on their weight. According to the Merck Veterinary Manual’s antihistamine dosages table, the recommended dosage of diphenhydramine is 2–4 mg/kg, IM, PO, or SC, q 8–12 h as needed. This means that pet parents should administer 2–4 milligrams (mg) per kilogram of body weight every eight to twelve hours orally or subcutaneously, as needed.

If you’re having trouble calculating the correct dosage for your dog, it may be best to consult your veterinarian before administering the medication.

Risks of giving Benadryl to dogs

One of the main risks of giving the medication to dogs is a Benadryl overdose. This can happen if the owner doesn’t follow the established guidelines based on weight and they administer more than what their dog needs. Some dogs can even have an allergy to diphenhydramine.

Substances like decongestants and alcohol are toxic to dogs. If the type of Benadryl you’re administering contains either of them, it could seriously harm your dog. Owners also need to watch out for how Benadryl interacts with other medications their dogs might be taking. Moreover, Benadryl should not be administered if a dog has certain health conditions — such as glaucoma, cardiovascular disease and others.

Common side effects of Benadryl include:

• Drowsiness
• Dry mouth
• Increased heart rate
• Hypersalivation
• Urinary retention

Summary of Money’s Guide on How Much Benadryl You Can Give a Dog

• Benadryl can be safe to treat dog allergies and manage anxiety symptoms when administered in appropriate doses.

• An incorrect dose of Benadryl could be extremely harmful, which is why you need to make sure you administer a dose based on your dog’s weight.

• The rule of thumb is to administer 2–4 mg of Benadryl per kilogram of body weight.

• Over-the-counter medications like Zyrtec and Claritin can be used as alternatives to Benadryl, but owners should first consult with their vets to make sure it’s safe.

• Owners should always consult with a licensed veterinarian before administering any type of over-the-counter medication.