Can You Give Your Dog Benadryl?

Affiliate Disclosure: Center for Dog Pain Relief, Inc. sometimes uses affiliate links within our content. This comes at no cost to you but helps us to be able to create more helpful content!

    Add a header to begin generating the table of contents
    Scroll to Top

    Benadryl is a home remedy that can be safe and effective in treating several ailments in dogs but you may have asked yourself you can give your dog Benadryl and if so, how much? Remember to always contact your veterinarian before administering any new medication to your dog. Read below to learn more about how Benadryl may be beneficial for your dog. 

    hand giving a corgi a red and white pill

    What is Benadryl? 

    Benadryl, generic name diphenhydramine, is an antihistamine that is used to relieve symptoms of allergies, rashes, and the common cold but does not treat underlying conditions. The medication comes in different forms including oral (tablets, chewable tablets, etc.) and topical cream spray, and gel. 

    How Does Benadryl Work? 

    Since Benadryl is an antihistamine, it counteracts histamine which is what the body produces during an allergic reaction. H-1 receptors, which are found on tiny blood arteries and smooth muscles, are blocked by Benadryl. When histamine binds to these receptors, it causes the blood vessels around the airways to enlarge, producing irritation and itching, as well as the muscles around the airways to constrict, making breathing difficult. The medication possesses drying effects on symptoms including watery eye, runny nose, sneezing, and itching. 

    Benadryl’s anti-motion sickness effect is achieved by inhibiting signals to the brain’s vomiting region. This only pertains to dogs and not humans.

    benadryl allergy medication 100 count

    What Are the Side Effects of Benadryl in Dogs?

    There are several side effects to be aware of when administering Benadryl to your dog. The most common side effects observed in dogs are: 

    • Lethargy 
    • Dry mouth/increased thirst 
    • Urinary retention 
    • Vomiting 
    • Diarrhea  
    • Lack of appetite 

    What Are the Signs of a Benadryl Overdose in Dogs?

    While there are side effects associated with Benadryl that may be commonly observed, it’s important to be knowledgeable of what the signs of a Benadryl overdose may look like. If your dog is experiencing any of the below, consult a veterinarian immediately. 

    • Abnormal heart rate or blood pressure
    • Excessive salivation
    • Seizures 
    • Tremors 
    • Trouble breathing 
    • Agitation or aggression 
    • Fever

    What is Benadryl Used to Treat in Dogs? 


    french bulldog puppy itching

    Benadryl for dogs is often used to treat itchiness that is caused by skin allergies. However, it may also be used to alleviate symptoms caused by other allergies including hives, environmental allergies, reactions to bee stings and vaccines, and other types of inflammation. Benadryl is effective in treating mild to moderate reactions. However, more serious reactions should be seen by a vet. 

    Short-term Anxiety

    The sedative effects in Benadryl may help dogs struggling with anxiety and phobias. However, it’s only a short term solution and should not be used in dogs that need anxiety medication on a regular, long-term basis. 

    Motion Sickness

    Benadryl for dogs is often used to relieve the symptoms of motion sickness. It’s especially effective if your dog needs to be transported a longer distance. The same receptors in your dog’s body that bind to histamines are associated with motion sickness, which is why Benadryl helps to reduce nausea during travel. In addition to this, the drowsiness caused by Benadryl may help to keep your dog calm during their trip. 

    When Should You Avoid Using Benadryl? 

    Benadryl should not be administered to dogs with certain existing medical conditions. In addition, inform your vet of any other medications that your dog is currently taking, as Benadryl may counteract with others. Dogs with the below medical conditions should not be administered Benadryl, including: 

    • Low blood pressure 
    • Cardiac conditions (including cardiovascular disease) 
    • Glaucoma 
    • Allergic to antihistamines 
    • Currently pregnant 
    • Neonatal dogs
    • Prostate enlargement 
    • Bladder or intestinal obstruction 

    What Is the Dosage For Benadryl For Dogs?

    According to the Merck Veterinary Manual, the safe dosage is 2-4 milligrams of Benadrylper kilogram of weight, or 0.9 to 1.8 milligrams per pound. This dosage can typically be administered two to three times daily. However, Benadryl dosage can best be determined by your veterinarian. 

    Be sure that the benadryl tablets contain only diphenhydramine and no alcohol. Do not administer time-release medication, as it can break down in the stomach at a faster rate than in humans and can lead to an overdose. In addition, speak to your vet before administering liquid Benadryl, as the liquid version is not absorbed the same as a tablet. 

    Remember to contact your veterinarian before administering a new medication, including over the counter medication. You can find a new vet through our specialist directory.

    Leave a Reply

    Your email address will not be published. Required fields are marked *