How Much Benadryl For A 90 Pound Dog

Last updated Feb. 15, 2022. Reviewed for accuracy on Dec. 11, 2019 by JoAnna Pendergrass, DVM

Benadryl is not yet FDA-approved for veterinary use, but it is generally considered safe for use in dogs with mild-to-moderate allergies. Benadryl is a brand name for an antihistamine (diphenhydramine HCl) that can help alleviate symptoms of allergic reactions and even anxiety. Histamine is a substance released by mast cells (a type of immune cell) and is responsible for inflammation and other allergy symptoms. The active ingredient in Benadryl is diphenhydramine, which works by blocking histamine receptors on a cell’s surface, meaning that the receptors cannot ‘accept’ histamine that tries to attach and trigger an allergic reaction.

Symptoms of allergic reactions that can be treated with Benadryl include hives, swelling, and itching. Severe reactions, like anaphylaxis, can be life-threatening and should be treated by a veterinarian (who may give an injection of diphenhydramine along with other emergency injections).

Many veterinarians approve Benadryl for home use as a regular go-to treatment. It may be suitable for:

Benadryl Tablets

According to the Merck Veterinary Manual, the standard dose for Benadryl is 2-4 milligrams per kilogram of body weight, or 0.9-1.8 milligrams (mg) of Benadryl per pound. Therefore, a simple and practical dose is 1 mg of Benadryl per pound of your dog’s weight, given 2-3 times a day.

How much Benadryl do I give to a 50 lb dog?

You should give 50 mg of Benadryl to a 50 lb dog, either as two 25 mg tablets, four 12.5 mg chewable tablets, or 20 ml of a Benadryl liquid form (12.5 mg/5 ml).

How do I calculate liquid Benadryl dose for dogs?

To calculate the liquid Benadryl (12.5 mg/5 ml) dose:

  • Determine the dose you need. The standard Benadryl dose is 1 mg per 1 lb.
  • The standard dose is the weight of your dog in pounds (lb).
  • Let’s count how much Benadryl is in one milliliter of a drug. 12.5 mg/5ml = 2.5 mg/1 ml.
  • Now we have to divide the desired dose by the amount in 1 ml.
  • The dogs weight in lb/ 2.5 mg = the amount of liquid Benadryl you want to give to your dog.
  • How much Benadryl can I give to my dog?

    Q: What dosage of Benadryl for dogs do vets generally recommend in the US?

    A: General dosage is 1 mg (milligram) per 1 lb (pound).

    Benadryl dosage in mg = Dogs weight in pounds * 1 mg

    Q: Whats the Benadryl dosage for dogs in mg per kg (kilograms)?

    A: General dosage is 2.2 mg(milligram) per 1 kg (kilogram).

    Benadryl dosage in mg = Dogs weight in kilograms * 2.2 mg

    Lets go one step further and calculate how much Benadryl for a dog we need in milliliters (mL).

    Our dog weighs 25 pounds and is extremely terrified of flying. ✈️ Our liquid Benadryl has a concentration of 12.5 mg/5 mL.

  • Lets calculate the number of milligrams we need. Benadryl dosage in mg = 25 lb * 1 mg = 25 mg
  • Lets turn milligrams (mg) into milliliters (mL). 12.5 mg/5 mL = 2.5 mg/1 mL = 2.5 mg/mL We need 22 mg of Benadryl: 25 / 2.5 = 10 mL
  • We got it figured out! We need 10 milliliters of Benadryl.
  • Now you know it all! Its time for a break:


    How much Benadryl do I give my 80 lb dog?

    Benadryl dosage for dogs.

    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.

    How many 25 mg Benadryl can I give my 80 pound dog?

    Benadryl is safe to give your dog for allergies, anxiety, motion sickness, and vaccine side effects. Though a typical Benadryl pill is 25 mg, you should only give your dog 0.9-1.8 mg per pound of weight.

    How much Benadryl can I give my 50lb dog?

    Benadryl Dose for Dogs

    Plumb’s Veterinary Drug Handbook recommends giving a standard dosage of 25 milligrams for a 25-pound dog two to three times per day. As a general rule of thumb, use 1 milligram per pound of your dog’s body weight. For example, a 50-pound dog would be given two 25 milligram tablets.

    Is 2 Benadryl OK for a dog?

    Dosage of Benadryl for Dogs

    The Merck Veterinary Manual recommends administering 2-4 milligrams of Benadryl per kilogram of body weight, two to three times a day. However, this dosage can vary depending on your dog’s medical conditions.