Benadryl for Dogs
Uses, Dosage, Side Effects, & How-To
Facts on Benadryl for dogs: the uses, safety, dosage, side effects, administration
how-to, and more. Learn more about Diphenhydramine and Benadryl for a dog

Benadryl (Diphenhydramine) is an OTC antihistamine, used to treat allergic reactions in
humans and some animals. Diphenhydramine was invented in 1943 and approved by the
FDA in 1946. You may have used it for yourself, but did you know that it can help your
pooch as well? The majority of vets permit the use of Benadryl on dogs and cats; this med
is used very frequently in canines.

The Uses of Benadryl for Dogs:

- Skin irritation and itching.
- Car sickness and vomiting.
- Insomnia and anxiety in dogs.
- Insect/bug/flea bites.
- Bee/wasp/hornet stings (including inside the mouth).
- Vaccination reactions (e.g., a Lyme disease shot).
- Hay fever, coughing/sneezing, and runny/stuffy nose.
- Asthma and inhalant allergies (e.g., to pollen/dust).
- Knots/lumps with fluid on the body.
- Irritation at the tail’s base.
- Muscle tremors.
- Ear/eye infections.
- Bites of some snakes.

Benadryl absorbs into the system fast and often takes a quick effect, sometimes in 30
minutes. However, in some cases, it may take 7-10 days to achieve notable results.

The Safety of Benadryl for Pets

In general, Diphenhydramine (Benadryl) is extremely safe for dogs, but there are a
number of critical precautions:

- This medication is counter-indicated with some conditions in dogs, including: prostatic
disease, glaucoma, hyperthyroidism, and cardiovascular disease.
- It may not be suitable for puppies. If you have a puppy, consult with your vet.
- For canines, only the pure medication is safe, where the only active ingredient is
Diphenhydramine; the Decongestant and Colds/Sinus versions are unacceptable.
- Liquid Benadryl has high alcohol content, which is unsafe for animals.
- Children's Benadryl is alcohol/sugar free, but it contains sodium – this is a concern for
dogs with some health concerns.
- It should not be used together with painkillers and decongestants. It may interact with
other medications, and may even be fatal. If your dog or cat is taking anything else – do
ask your veterinarian. In general, it is considered safe with heartworm and flea tablets, and
- It is very important not to exceed the dosage prescribed.

Some people recommend using a tiny amount of the medication and checking the reaction

Dosage of Benadryl for Pets

There are 2 ways to determine the dose of Benadryl for a pet, and I’ll state both of them

1. Diphenhydramine is administered in the dosage of 1mg per 1 lb of the pet’s weight 3
times a day (every 8 hrs). Example: a 30lb dog is given 30mg of the medication 3 times a

2. Pets are divided into 3 weight categories; the medication is given 3 times a day, every 8
- 30 lbs and smaller pets: 10 mg
- 30-50 pound dogs: 25 mg
- 50 lbs and larger dogs: 50 mg

The dosage depends on the pet’s weight, and the above are general recommendations.
To find out how much Benadryl to give to your pet, you need to obtain professional advice
from a veterinarian. Too small of a dose may not help, while exceeding the dose can be
very dangerous. Also, the vet will help you determine the frequency of administration, such
as every 4, 8, or 12 hrs. In addition, they will ask you questions to determine if it’s an
allergic reaction or something else. If your financial situation doesn’t allow for a paid visit,
you should be able to obtain free help by phone.

Side Effects of Benadryl in Pets

The most common side-effects
mild disorientation and drowsiness
dry mouth
lack of appetite
problems breathing
fast heart beat
urinary retention
Some side-effects can be prevented. For example, to prevent vomiting, give the med with
food. To prevent the disturbance of appetite, feed your pet prior to giving the med. In case
of side-effects, call a vet.

How to Give Benadryl to Pets

Here are some ideas on how to give this medication to a pet:
the pill or capsule placed into chunks of meat
a liquid gel capsule dipped in a tasty treat
anal administration
Most commonly, this medication is given orally, in capsules or tablets.
Please contact your vet to find out more on the use of Benadryl for dogs.
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