Benadryl for Cats: A Quick Guide

Benadryl for Cats: A Quick Guide

  • Kirsten Thornhill - 10.05.2021

Should Cats Take Benadryl?

Your four-legged friend means the absolute world to you! You can trust us when we say, we totally get it! Our cattos and doggos are our family members, and we know you’d do just about anything and everything to keep them happy, well, and healthy. 

However, we don’t have to tell you that it isn’t always biscuits and gravy. Even the most responsible pet owners can agree that problems come up out of nowhere! In these instances, cat owners can find themselves wondering what in the world to do next. 

One of these unpredictable health concerns could easily result from your cat experience an allergy attack or allergic reaction. Just like us humans, cats can experience allergies to a wide array of things including vaccines, environmental toxins, and food. Thus, it is imperative to know what to do if and when such an allergic reaction happens. 

In today’s article, we’ll cover the popular and conventional medication: Benadryl. Is it safe for your furry friend? Is there potential for adverse side effects? Knowledge is definitely power my paw parent friends! The more you know about preventing and treating allergic reactions, the better equipped you will be to handle the situation appropriately.

Let’s get to it!

What is Benadryl for Cats?

Benadryl for felines is a conventional and traditional medication primarily used for treating irritation, pain, and uncomfortable adverse effects associated with allergic reactions and seasonal allergies. 

Benadryl will typically come in liquid and tablet forms, but can also be injected directly if the allergic reaction is extreme or severe. Oftentimes, Benadryl can help with insomnia as well as motion sickness nausea.

Being one of many over-the-counter (OTC) medications available to you, Benadryl aims to ease seasonal allergies in humans. But, when it comes to our furry felines, paw parents need to be extremely careful. Even if your veterinarian deems Benadryl as being safe for your cat to take, even with appropriate dosage, doesn’t necessarily mean that other human drugs are safe for feline consumption. 

How Does Benadryl Work?

Let’s first start with histamines. These inflammatory substances attach to cells, typically causing what we commonly refer to as an allergic reaction. 

Benadryl is an antihistamine. Thus, it works by blocking histamines from attaching to histamine-1 (H-1) receptors on small blood vessels and smooth muscles in ours and our cat’s body. This, in turn, prevents an allergic reaction from happening (or so intended). 

In a general sense, Benadryl is a brand name for its active ingredient: diphenhydramine. Diphenhydramine, aka Benadryl, can be purchase at your local grocery store or drug store presumably and has the same, if not similar, effects. 

Can I Give my Cat Benadryl?

The buzzing question when it comes to searching away on the internet when your cat is in need. In short, our answer is “yes, you can give your cat Benadryl, but…..”



When appropriately administered with recommendations from your veterinarian beforehand, Benadryl should be safe to give to your felines and canines. However, there are a handful of things that you should know before giving your furry friend this medication. 

What is Benadryl Used For?

As a human, I’m sure you’ve taken Benadryl yourself once or twice, or have at least heard about what it can do for humans. But what about our cats? It may come as a surprise to you that cats can suffer from almost identical illness and health concerns as us humans, whilst also experiencing the same benefits for aid from this medication. 

1. A Mild Sedative

Your veterinarian may recommend Benadryl as a mild sedative for your cat. For instance, most felines aren’t very fond of traveling. Being stuck in a crate for hours on end can cause total havoc in their mind. Benadryl may be helpful in these cases as it can be used to help calm your cat, allowing them to calm down and rest until you reach your destination.

2. Vaccine Reactions

It’s totally possible that cats can have allergic reactions to new medications as well as traditional vaccines. We really can’t stress enough just how important it is to keep a close eye on your cat after they’ve received any new medications or shots. Even cats who have never had an allergic reaction to specific vaccines could endure unexpected side effects without any signs or warnings. Sometimes this allergic response can become extreme, with Benadryl alone not being enough to help. 

3. Feline Allergies

Just like us humans, cats can suffer from seasonal allergies from just about anyone and anything that their bodies don’t really like. Many cat allergies can come on out of nowhere, unfortunately. For example, cats can all of a sudden develop food allergies to their same food they have been eating for years. Not to mention, things like household cleaners, detergents, or perfumes can cause your cat’s body to experience an allergic reaction quickly, demanding that you act swiftly. 



4. Insect Bites

If you live anywhere near where mosquitos live, you’re well aware of how awful it can be during those hot summer months, for you and your pets. 

Insect bites are a real issue, not only for us but our cats too. Just one single bug bite can cause weeks and weeks of itching, biting, and scratching. 

If you’re experiencing itchy mosquito bites all over your body, it’s likely that your cat is too. Keep an eye on any bites or irritated areas on your cat to ensure that they heal properly. The constant scratching and itching and licking can lead to a gnarly infection, with treatment likely needed around the corner. 

As many cats have a love for being mischievous, they often get into things and places they shouldn’t. For instance, beehives (of all things). If your cat gets stung by a bee, first things first, take out the stinger. Depending on how bad of a sting your cat endured, Benadryl will likely be your vet’s first recommendation.

5. Feline Cold

The common cold, for you, for me, for our cats too. Many feline parents ask whether or not Benadryl can help if and when their cat gets a cold. In short? Yes and no, here’s why. 

Benadryl can definitely be helpful in lessening symptoms associated with a common cold. But, it’s not your ‘end all be all’ cure of their cold. The same can be said for allergies. Benadryl won’t “cure” your cat’s allergies, but it may be able to help. Again, your cat will still be allergic to whatever it was, but the medication can help in reducing their symptoms. 

In regards to the common cold, paw parents must ensure that the cold itself is getting better versus taking medication to mask the symptoms. If that makes sense? Colds often come on from a viral or bacterial infection, some of which may require antibiotic or veterinarian treatment. 

6. Skin Allergies

Felines can also experience skin allergies, causing them to itch and scratch almost uncontrollably. This may lead to horrible agitation and aggression as well as them being extremely uncomfortable. Bumps, inflammation, and redness are often quick signs that an allergic reaction is occurring, but these can be hard to detect if the reaction isn’t yet severe. In these instances, having Benadryl nearby can really save the day. 


What are Cat Allergy Symptoms?

Before you can know when Benadryl is supposed to save the day, it’s crucial that you are able to recognize the signs and symptoms of allergic reactions and allergies. 

The following are signs and symptoms of common allergies.

  • Coughing
  • Itchy Skin 
  • Irritated eyes
  • Wheezing
  • Diarrhea
  • Vomiting
  • Ear infections
  • Swollen Paws
  • Snoring
  • Sneezing

What are Cat Allergic Reaction Symptoms?

Allergic reactions in cats can range from very very mild to extremely severe. In extreme cases, anaphylaxis may occur. This is a type of shock allergic reaction that should be treated as an immediate medical emergency. If not handled right away, this could be deadly. 

Signs of anaphylaxis shock may include, but is not limited to:

  • Collapsing
  • Uncontrolled urination
  • Excessively lethargic
  • Excessively vomiting 
  • Trouble breathing
  • Uncontrolled bowel movements

What are the Side Effects of Benadryl for Cats?

Now that you are aware of the ways that Benadryl can help your furry friend, it’s important to also understand the potential side effects associated with this medication. 

  • Hyperexcitability
  • Dry mouth
  • Changes in urination frequency
  • Loss of appetite
  • Drowsiness
  • Possible sedation
  • Diarrhea
  • Vomiting



If you begin to notice any of these adverse side effects it’s important that you closely watch your cat to ensure that things don’t worsen quickly. In addition, talk to your veterinarian. They will be able to help guide you through your cat’s personalized health concerns. Again, giving your cat the recommended dosage of Benadryl is important! Overdoses can and do occur and may result in irreversible damage. 

Benadryl for Cats: Final Thoughts

When all is said and done, we know that you only want what’s best for your furry friend. In order to make sure that your cat’s life is at its best possible living standard, you have to always prepare for the unexpected as a cat mom or dad. This also means planning for unexpected allergic reactions or seasonal allergies. 

For many cattos, Benadryl can be a safe and effective way to help reduce their allergy symptoms. Thus, it’s important that you follow your vet’s recommendations and guidelines for the appropriate dosage for your cat’s needs. 


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