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

Medically reviewed by Nicole Wanner, DVM

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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.


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.


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.


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.


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)
5 2ml 1/4 tablet
8 3ml 1/4 tablet
10 4ml 1/4 tablet
13 5ml 1/2 tablet
15 6ml 1/2 tablet
20 8ml 1/2 tablet
25 10ml 1 tablet


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


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


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

CBD Oil for Cats can help with reduction of inflammation and management of discomfort associated with allergies. CBD interacts with the ECS, or endocannabinoid system. This system plays a vital role in managing inflammation throughout the body.

And while allergic reactions can make your cat's skin irritated, CBD for overgrooming in cats can provide relief. It has various features which make it beneficial for cats who are anxious or having allergic reactions causing them to overgroom.

Another good option is CBD cat treats, which are just as effective as oil but more convenient to give to your cat.

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.


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.


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