Can Cats Have Benadryl? We Explore The Side Effects, Dosage, And Alternatives – Relievet

Call Us 9-5 (M-F) PST | (858) 352-6935

Free US Shipping | Free US 2-Day Over $100

30% Off Every Order When You Subscribe & Save

Money Back Guarantee | Made In The USA

Can Cats Have Benadryl? We Explore The Uses, Side Effects, Dosage, And Natural Alternatives

Christopher Kjolseth - August 14th 2020

Accuracy Review & Edit: Nicole Wanner, DVM - July 9th 2021


When you have symptoms of allergies, you probably reach for a Benadryl to ease the itch. Likewise, it is also common for dogs to take Benadryl to fend off any allergic reactions, but what about Benadryl for cats?

Though Benadryl is readily available and considered safe for people, drugs don't always react the same way for our cats as they do for us.

Read on to learn more about Benadryl for cats as we explore the usage, side effects, and natural alternatives.  

Table Of Contents

  • What Is Benadryl?
  • Can Cats Have Benadryl?
  • What Is Benadryl Used For?
  • Benadryl Dosage for Cats
  • Is Benadryl Safe for Cats?
  • Side Effects of Benadryl
  • Natural Alternatives to Benadryl for Cats
  • When Should You Go to the Vet?
relievet ad 25 off desktoprelievet ad 25 off

What Is Benadryl?

Benadryl is the brand name for an antihistamine called diphenhydramine hydrochloride. It is primarily to treat allergies in humans. Benadryl is a readily available over-the-counter drug, so you don't need a prescription to obtain it.

Can Cats Have Benadryl?

Benadryl is not FDA approved for use in cats, but it is widely considered by the veterinary community to be safe.

However, it is possible for cats to overdose from this medication, so you should make sure you follow the dosage guidelines very carefully. 

Pregnant cats, cats with certain underlying health conditions, or cats currently taking other medications (we cover these later on) should not be given Benadryl, as serious adverse reactions can occur.

In these situations, make sure you contact your vet before trying to give Benadryl to your cat.

What Is Benadryl Used For?

Usually, people give Benadryl to cats with itchy skin or allergic reactions, but you might use it to help with nausea on car or plane rides, as a sleep aid, for responses to injections, or bug bites. People are often looking for ways to calm down their cats at night and Benadryl may be a temporary solution. 

If you are looking for a sleep aid or something to relax for your cat, be aware that while Benadryl can make some people sleepy, it often has the opposite reaction in cats, causing them to be even more excitable than usual.

For this reason, you might want to look at alternatives like CBD oil for cats or discuss prescription medications with your vet. 

You should consult your vet in certain situations like reptile, insect, or snake bites, as in some cases, they can be fatal to your cat if not treated quickly.  

Here's a list of situations where you might consider giving Benadryl to your cat:

  • When an insect, such as a scorpion or a bee, bites or stings your cat.
  • When your cat is itching or scratching due to food or environmental allergies.
  • When your cat is traveling and is prone to motion sickness.
  • When your cat needs something to make him or her sleepy.
  • When your cat is about to have a vaccination that he or she typically has allergic reactions to.

Benadryl Dosage for Cats

It's important to get the dosage of Benadryl for cats right, as there can be real problems if they overdose.

Before you attempt to find the correct dosage of Benadryl for your cat, make sure that you only give them Benadryl tablets that do not contain any other ingredients, like Tylenol, or a decongestant. 

If you go the route of liquid Benadryl, you will want to use the children's liquid or liquid Benadryl from your vet. 

The generally accepted dose is 1mg of Benadryl per pound of your cat's body weight every 8-12 hours. 

You can use the following dosage table to find the correct dose for your cat:

Benadryl For Cats Dosage Table

Animal weight Childrens liquid (12.5mg / 5ml)
Tablets (25mg)
2ml1/4 tablet
3ml1/4 tablet
104ml1/4 tablet
135ml1/2 tablet
156ml1/2 tablet
208ml1/2 tablet
2510ml1 tablet

Is Benadryl Safe for Cats?

Benadryl is generally considered to be safe for cats if given at the correct dosage. An overdose of Benadryl for cats can have serious negative side effects and even cause death. 

Do not give your cat Benadryl without consulting your vet if they are currently taking any of the following medications:

  • Amitraz
  • Central Nervous System Depressants (CNS Depressants)
  • Cisapride
  • Metoclopramide
  • Selegiline
  • Barbiturates
  • Benzodiazepines

Side Effects of Benadryl

Although Benadryl can help cats cope with itchy skin, allergic reactions, or bug bites, it can have some negative side effects, especially when an overdose occurs. 

If you encounter any of the following, you should monitor your cat closely, and if the symptoms persist or worsen, you should contact your veterinarian. 

  • Hyperexcitability
  • Lethargy and possible sedation
  • Vomiting and diarrhea
  • Constipation
  • Loss of appetite
  • Changes in urination

Natural Alternatives to Benadryl for Cats

More and more cat owners are looking for natural alternatives to pharmaceutical drugs to help their cats (and themselves) with allergies, itchy skin, nausea, or to encourage them to relax. Most cat owners know they need the cat to be calm especially when they are cutting its nails.

Here are some of the best natural alternatives to Benadryl for cats:

Fish Oil

Since fish oil is an excellent source of the fatty acid omega-3, you might want to consider adding it to your cat's food.

Omega-3 aids the skin's immunity and reduces infections. Additionally, omega-3 is an anti-inflammatory that can help reduce itching and hot spots.

Note that it is best to avoid cod liver oil since it's too high in vitamin A and D for cats. 

Coconut Oil

Coconut oil contains medium-chain fatty acids, which are “good fats'' that may have anti-inflammatory properties. It also contains lauric acid, which is antibacterial.

Coconut oil can help heal damaged skin and soothe your cat’s itchy or dry spots.

You can apply the oil topically since it is non-toxic if your cat licks it. If your cat licks too much coconut oil, though, they may experience stomach upset.


Chamomile contains apigenin, which inhibits chemicals that cause inflammation. Also, chamomile works as an antiseptic that can kill yeast and bacteria.

You can brew chamomile tea, cool it, then apply as a topical spray. If your cat isn’t a fan of spray bottles, dry dipping your fingers in and dabbing it on the affected area.

Chamomile’s effects have not been formally assessed in cats.


Acidophilus is a friendly type of bacteria that helps regulate the immune and digestive systems. When these systems are in tip-top shape, your cat will be less likely to develop allergies.

If your cat has food allergies or stomach problems, acidophilus may help reset bacterial populations in the gut to provide some relief. Diet changes and consulting your vet are the best way to handle food allergies in cats.

CBD Oil For Cats 

Cannabidiol (CBD) oil is made by extracting the CBD from the hemp plant. As CBD enters the body of your cat, it interacts with CB2 receptors. Upon interacting with your cat's CB2 receptors, CBD activates the endocannabinoid system. This system plays a vital role in managing inflammation throughout the body.

Some cats will not like oil, but there are CBD cat treats that work just as well. The only difference is dosage increases because of the digestive processes. In stead of loading the cat up with tons of treats, get effective CBD cat treats the first time.

Unfortunately, CBD has not been tested for allergies or inflammation in pets. Still, if your cat suffers from allergies, CBD may be worth a try.

Apple Cider Vinegar

Thanks to its antibacterial and antibiotic properties, apple cider vinegar is excellent for use as a wash to remove irritants from your cat's skin. 

Start by mixing the apple cider vinegar with an equal amount of water, as apple cider vinegar on its own can be too potent for your cat's skin. Then, apply it on your cat's skin using a paper towel.

Avoid applying apple cider vinegar to your cat’s skin if the skin is broken, as with a cut, puncture, or severe rash.

When Should You Go to the Vet?

If you are giving your cat any of the medications mentioned earlier that do not mix well with Benadryl, consult your vet. Your vet will most likely recommend an alternative to Benadryl that does not cause adverse effects when combined with your cat's medication.

If your cat is bitten or stung by any venomous reptile or insect, you should consult your vet, as in some cases, this can be fatal if not treated quickly.

It's important to know that if your cat has fleas, the only solution is to get rid of them; Benadryl will only mask the symptoms and not solve the problem. 

If you notice any side effects after giving your cat Benadryl, closely monitor your cat. If your cat's condition worsens, contact your vet immediately. 

Popular Products

CBD Oil For Dogs
Regular price
Sale price
CBD Soothing Skin, Paw, and Nose Balm for Dogs
Regular price
Sale price
CBD Oil For Cats
Regular price
Sale price
Zen Calming CBD Chews For Dogs
Regular price
Sale price
Mobility Hip and Joint CBD Chews For Dogs
Regular price
Sale price
CBD Oil For Parrots, Cockatiels, and Conures
Regular price
Sale price
Grass Fed Beef Liver - Freeze Dried - 120 Count
Regular price
Sale price
Wild Caught Alaskan Salmon - Freeze Dried - 120 Count
Regular price
Sale price

Biscuit's Story

biscuits story

To say Biscuit lived an active life would be an understatement. Unfortunately, at the age of 10, she started to limp after trips to the dog park.

It broke my heart to see her in pain doing what she loved the most. I started feeding her a raw food diet and added high-quality supplements to ensure her nutritional needs were met. Unfortunately, while she loved the food, the limping persisted. I decided to go to the vet. They quickly diagnosed her with osteoarthritis and prescribed a drug to help.

Her limping stopped, and she was in less visible pain. For the first week, it seemed that this was the solution. A few days later, it was to my absolute shock that she...

Recent Posts:

blog images

CBD Oil for Dogs in Thunderstorms

CBD oils like the ones from Relievet work to relieve dog anxiety (It's right in our name!). Many of our customers report that their dogs are calmer and happier during trigger events like storms and fireworks.
blog images

CBD for IVDD in Dogs – Does It Work?

Intervertebral Disc Disease is a condition where the spinal discs between the vertebrae of the spine degenerate. Learn more about this condition and what CBD oil can do for your dog!
blog images

CBD for Dogs with Cancer

This article explores CBD oil for dog cancer, its relationship to post-cancer treatments, and looks at some potential natural remedies.
blog images

CBD for Cats with Cancer

This article covers CBD for cats with cancer, CBD safety for cats, signs of cancer, types of cancer, and the best CBD oil for cats with cancer.
blog images

CBD for Dogs with Hip Dysplasia

This article explores hip dysplasia, signs of hip dysplasia, CBD oil for hip dysplasia, CBD dosage, and the best CBD oil for dogs with hip dysplasia.
blog images

CBD Oil for Cats with Kidney Disease

The kidneys play a crucial role in maintaining your cat's health, and if they fail, they can cause significant problems, including some that are life-threatening.

Read on to find out if CBD oil can help cats with kidney disease.
blog images

CBD for Aggressive Dogs

This blog gets the leash around the causes of aggression, CBD oil for aggressive dogs, CBD oil vs. Prozac, CBD dosage, and the best CBD oil for aggressive dogs.
blog images

CBD for Dog Pain

We explore CBD for pain and inflammation, CBD's function in suffering dogs, the best CBD for dog joint pain, and the safety of CBD in conjunction with traditional pain medications.
blog images

CBD For Dogs Anxiety

This blog puts forward a fair assessment of CBD for dog anxiety, the effectiveness, the safety, the proper dosage, and helps you avoid the pitfalls and find the best CBD oil for dog anxiety.
blog images

CBD Oil for Dog Seizures

Everything you need to know about CBD oil for dogs with seizures and help finding an effective product and dosage for your dog.
blog images

What Is The Best CBD Oil For Dogs With Arthritis?

Finding the best CBD oil for dogs with arthritis could dramatically change your dogs' life and yours. This article breaks it down the research to help you buy...

Accuracy Review by:
Dr. Nicole Wanner is a veterinarian and published scientific researcher. She studies the effects of CBD as a Ph.D. candidate.

Drop element here!

Net Orders Checkout

Item Price Qty Total
Subtotal $0.00

Shipping Address

Shipping Methods