Benadryl, which is a brand name for the drug diphenhydramine hydrochloride, is an antihistamine used to treat symptoms of allergies in cats, including swelling, itching, sneezing and hives, that result from insect bites or stings, exposure to environmental allergens like grass or pollen, and reactions to flea bites. Read on to find answers to the most common question about Benadryl for cats.
Is Benadryl Safe for Cats?
Benadryl is generally considered to be safe for cats. However, as with all medications, Benadryl should be used correctly. It’s best to call your veterinarian to ask about using Benadryl for your cat because some cats should not take Benadryl, including cats with certain medical conditions (for instance, heart problems or glaucoma), those taking other medications, and pregnant or nursing cats.
If you are using Benadryl because your cat is having an allergic reaction or experiencing itchy skin, always follow up with your veterinarian. Benadryl will treat a cat’s symptoms (swelling, itching, sneezing, hives), but it doesn’t treat the underlying cause of the swelling or itching. For instance, your cat might be suffering from an allergy to flea bites, but simply treating the cat for the itching without addressing the flea infestation will not cure your cat.
Additionally, cats that are scratching and chewing due to allergies or another skin condition need additional medical care to help address the primary reason for the itching, as well as to treat and secondary conditions that might have developed like skin infections.
In cases of severe allergic reactions (anaphylaxis), Benadryl might not be enough to stop a reaction. Cats that have been stung or bitten by insects or snakes require urgent veterinary attention, even if you are able to administer Benadryl at home.
If your cat is experiencing facial swelling, difficulty breathing, vomiting, diarrhea, lethargy, seizures or collapse, bring her to a veterinarian immediately. If this happens after normal business hours and your veterinary clinic is closed, bring your cat to the nearest emergency veterinary hospital.
Side Effects of Benadryl in Cats
It is possible for some cats to experience side effects when taking Benadryl. Some common side effects of Benadryl that you might notice in your cat include:
- Dry mouth
- Difficulty urinating
Cats will usually show signs of unwanted side effects within one hour of taking Benadryl. If you notice your cat exhibiting any of the above signs while taking Benadryl, stop giving the medication and bring your cat to the veterinarian to be examined.
Although some cats become drowsy when taking Benadryl, others become amped up. For this reason, giving Benadryl to cats for anxiety or for sedation is not usually the best option.
Even though Benadryl is usually considered to be safe for cats, it is possible overdose your cat with Benadryl. Avoid giving a lethal dose of Benadryl by weighing your cat before giving the medication and giving only the recommended amount of Benadryl.
Never give more than 1 milligram of Benadryl per pound of body weight and never give Benadryl more often than every eight hours in a 24-hour period. Giving more than the recommended dose of Benadryl or giving too many doses in a 24-hour period increases the risk of Benadryl overdose in cats.
As with all medications, use Benadryl for cats cautiously and carefully, and always with the guidance of your veterinarian. Signs of Benadryl overdose in cats may include one or more of the following:
- Rapid breathing
- Slow breathing
- Difficulty breathing
- Rapid heartbeat
How Much Benadryl Can I Give My Cat?
You can buy Benadryl over the counter at most pharmacies, grocery stores and big-box stores. Benadryl is sold as tablets or liquid. It’s important to only use plain Benadryl. The only active ingredient should be diphenhydramine HCl. Never use combination medications (for instance, diphenhydramine combined with a decongestant).
The typical dosage of Benadryl for cats is 1 milligram per pound of body weight. Depending on what the Benadryl is being used to treat, cats may take Benadryl up to three times a day (every eight hours in a 24-hour period). Consult with your veterinarian to find out how often your cat can safely take Benadryl.
Benadryl tablets come in 25 mg. If your cat weighs 12.5 pounds (give or take a pound or so), you can break one tablet in half and give that to your cat. It gets trickier for cats weighing much less than 12.5 pounds or much more than 12.5 pounds (unless your cat is quite large—a 25 pound cat can take a full 25 mg tablet of Benadryl).
Liquid Benadryl for cats might be easier to measure and also easier to give to a cat (cats are notoriously difficult to get to swallow pills). Your veterinarian might sell special liquid Benadryl for cats, or you can use children’s Benadryl. Be sure to check with your veterinarian to makes sure all of the inactive ingredients in over-the-counter liquid diphenhydramine are safe for cats. Alternatively, a compounding pharmacy might be able to make a liquid Benadryl in a flavor cats like. If you want to go this route, ask your veterinarian to recommend a compounding pharmacy.
How to Give Benadryl to Cats
If giving Benadryl tablets, hold your cat in your lap or place her up on a table. Carefully point your cat’s head toward the ceiling, open your cat’s mouth by placing one finger on the lower teeth and quickly place the pill as far back into the throat as possible. then allow your cat to close her mouth and gently stroke her under the chin to encourage her to swallow the pill.
If giving liquid Benadryl, use the measuring syringe included in the package to measure the correct dose of Benadryl. Squirt the liquid into your cat’s mouth, trying to aim the syringe far back into the mouth to the back of the tongue. Whether giving tablets or liquid, softly blowing on your cat’s face and nose may help encourage your cat to swallow the Benadryl. Alternatively, you can try hiding a tablet into food or mixing liquid into food.
Benadryl for Cats Dosage Chart1
|Cat’s weight||Benadryl (mg)||Liquid (12.5 mg per 5 mL)||Tablets (25 mg)|
|6 pounds||6 mg||2.5 mL||1/4 tablet|
|8 pounds||8 mg||3 mL||1/4 tablet|
|10 pounds||10 mg||4 mL||1/4 tablet|
|12 pounds||10 mg||4 mL||1/2 tablet|
|15 pounds||15 mg||6 mL||1/2 tablet|
|20 pounds||20 mg||8 mL||1/2 tablet|
|25 pounds||25 mg||10 mL||1 tablet|
Use Benadryl for Cats Safely
Benadryl for cats can safely and effectively help if your cat is itchy, sneezing or experiencing swelling. However, even though Benadryl is easy to obtain and give to your cat at home, it is vital that you seek veterinary care for your cat as soon as possible.
About the Author
Jackie Brown is a freelance writer specializing in the pet industry. She writes on all pet and veterinary topics, including general health and care, nutrition, grooming, behavior, training, veterinary and health topics, rescue and animal welfare, lifestyle, and the human-animal bond. Jackie is the former editor of numerous pet magazines and is a regular contributor to pet magazines and websites. She can be reached at jackiebrownwriter.wordpress.com
This article is for informational purposes only and is not intended to be a substitute for professional veterinary care. Always talk to your veterinarian about questions you may have regarding your pet’s medical condition. Do not delay seeking professional veterinary advice because of something read on the internet.