Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Why Is My Cat’s Bottom Lip Swollen? 9 Vet Reviewed Reasons & What to Do

Share

cat opening its mouth

Your cat’s health is your responsibility—but sometimes you might not be sure whether anything is wrong. If you notice your cat has a swollen bottom lip, should you be worried about it? Should you call an emergency vet? The truth is, there are many different causes of swollen lips. That can make it tricky to diagnose at home.

Luckily, it’s not a sign that you need to take emergency measures unless your cat is struggling to eat or breathe. Here are nine common reasons for cat’s having a swollen bottom lip.

divider 3 paws

The 9 Reasons Why Your Cat’s Bottom Lip is Swollen

1. Food or Contact Allergy

One of the most common causes of swelling is an allergic reaction to something that touches your cat’s mouth. Your cat may have a food allergy that is causing a reaction. The most common allergies in cats are to specific meat proteins, such as chicken, beef, or pork. Consider switching food to see if your cat reacts better to a different brand and flavor of food.

Another possibility is an allergy to something else your cat regularly touches, such as a toy or food dish.

If you are concerned about the health and well-being of your pet, seek veterinary advice for the best course of action.


2. Insect Bite or Sting

Another common reason for a cat’s swollen bottom lip is due to a reaction to an insect bite or sting. Fleas, ticks, and mosquitos can all cause swollen bites anywhere, including the lips. Demodex mites are another insect that can cause swelling, hair loss, and other issues. In fact, the lack of fur around your cat’s lips might leave them especially vulnerable.

Cats can also get bee stings around their mouth if they try to bite or pick up a bee. Insect bites and stings usually will heal on their own, but if you see recurring bites, it’s possible your cat is flea-infested.

stray cat with skin disease scratching the ear
Image Credit: nu aom, Shutterstock

3. Toxin Exposure

Along with allergic reactions, your cat can also experience lip swelling from toxic reactions. This usually occurs when your cat eats something toxic to cats. One common culprit that often leads to swelling is the pothos plant—a beautiful and hardy houseplant with shiny, heart-shaped leaves that can come in a variety of green, yellow, and white patterns.

Look for other signs of poisoning, such as vomiting, bloody stools, diarrhea, and lethargy, to know if your cat is in serious danger.


4. Tumor

Oral or skin cancer is somewhat rare in cats, but it is not unheard of. Small tumors can develop around your cat’s mouth and lips. A vet assessment is needed to diagnose the tumor and decide if it’s benign or cancerous. Tumors are much more common in elderly cats than young cats.


5. Dental Disease

Your cat might also be facing swelling due to any number of dental issues—a broken tooth, an abscess, or tooth rot are all possible culprits. If this is the case, you may see other signs of disease when you open your cat’s mouth, and your cat will probably show signs of pain. Depending on the issue, a small surgery or medication might be needed.

Vet checking on Russian Blue cats teeth
Image Credit: sirtravelalot, Shutterstock

6. Infection

Various types of infections can cause swelling around your cat’s bottom lip. This can include fungal infections such as ringworm or bacterial infections in a small cut or wound on your cat’s lip. Treatment generally involves antibiotics or antifungals to help kill the infection.


7. Immune System Disease

Pemphigus is an auto-immune disease that can affect your cat’s skin. It can cause swelling along with scabs, redness, and lesions anywhere on your cat’s skin, including the lower lip. It can be diagnosed with a skin biopsy. There are various treatment options available, but not all cats respond well to treatment.

vet giving medicine to a cat
Image Credit: Prostock-studio, Shutterstock

8. Feline Acne

Feline acne often occurs in the hair follicles of the chin, causing pimples, swollen areas, and clogged pores. Treatment varies depending on the situation—sometimes a change of food dish and better cleaning is all that’s needed, but other cats need oral or topical medication. Usually, feline acne is a gross but ultimately minor problem.


9. Eosinophilic Granuloma Complex

Eosinophilic granuloma complex refers to a condition in which small swollen lumps called granulomas develop around your cat’s lips. Although this can sometimes be caused by allergies, at other times, the cause is unknown. Although we don’t always know what causes the eosinophilic granuloma complex, the good news is that it is generally easy to treat with anti-inflammatory drugs.

If you suspect that your cat is suffering from any of the above, it’s best to contact your vet for more information and to determine your next steps.

divider cat paws 2 oct 2024

Last Thoughts

As you can see, there are so many different reasons that your cat’s bottom lip might be swollen, . Although you can rule some of these reasons out at home, it’s really best to take your cat to the vet and get a proper diagnosis, especially if the swelling is persistent or recurring. And, of course, if your cat is having difficulty eating or breathing, you should seek treatment right away.

Every cause has a different treatment, and finding the right way to help your cat can be tricky. Luckily, swollen lips are usually treatable.


Featured Image Credit: dimitrisvetsikas1969, Pixabay

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

2 Responses

  1. we have been taking care of a feral cat for the past 16 months the cat has become a family pet however the animal remains very friendly but we can't hold her and pet her.
    The animal has a notch in her ear so she
    has been spayed. Her lower jaw is
    swollen and the tongue is sticking out she can't eat or drink.How can I get her in a kennel to transport her to a vet

    1. Hi John,
      Thank you for taking care of this cat. You cant find helpful advice and tips in the following post:

      https://www.catster.com/lifestyle/how-to-trap-a-feral-cat-for-tnr/

      https://www.catster.com/lifestyle/how-to-get-a-feral-cat-into-a-carrier/

      https://www.catster.com/lifestyle/how-to-catch-a-stray-kitten/

      We hope this helps!

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Catster's Digital Magazine is Back!

Vet-approved health & behavior advice

Real cat stories & community features

Chatting About the Importance of Spaying/Neutering, Cat Retail Shopping Ban & Red-Level Storms | Chatty Cattys, Episode 30

In this episode of Catster’s Chatty Cattys podcast, Nicole and Dr. Karyn are celebrating a major legal win for pets before diving into...

Is Your Cat Happy? Here’s How You Can Tell

Cats have a reputation for being indifferent, even inscrutable. But despite their seemingly ambivalent appearance, cats experience many emotions, including happiness, and they...

Human Brains Age Like Cats – New Study Debunks the 7-Year Rule

If you’ve ever caught your senior cat staring blankly at a wall, wandering the halls at 3 am, calling out for no clear...

Chatting with Devin About Here! Have a Kitten, Fostering, & Why Two Are Better Than One | Chatty Cattys, Episode 29

In this episode of Catster’s Chatty Cattys podcast, Nicole & Dr. Karyn sit down with Devin, the founder and one-woman show behind “Here...

More related

10 Vet-Verified Ways to Keep Cats Out of Flowerbeds: Easy & Expert Tips

We all love our feline friends. They keep us company and even add beauty and elegance to our houses. But there are probably...

Catster’s Guide to Winter Holiday Hazards (With Safety Tips)

We’ve all heard the apocryphal statement that “if you build it, they will come”. Great movie, although there could be more cats… But...

How Do I Get My Cat Used to a Harness? 10 Vet-Approved Tips

As creatures of habit, cats dislike change. Something as simple as moving their litter box can cause them to get anxious and start...

Is Cat Cremation the Right Option for Your Pet? Vet-Reviewed Guide

Losing a beloved cat is one of the most painful moments in life. Whether your loved one is nearing the end of their...

Keep reading

6 Best Cat Cleaning Wipes in 2026 – Reviews & Top Picks

It’s no secret that our felines can get messy occasionally. Whether rubbing their leftover bathroom particles across your carpet or running through the house with muddy paws, wipes can be handy for cleaning up after our frisky kitties. If you...

hand wiping an orange cat with pet wipes

Is It True That Male Cats Kill Kittens? Vet-Reviewed Behavior Explanation

If you’ve heard that male cats might sometimes harm or kill kittens, you’re likely reading this now to see if there’s any truth to it. This is particularly critical if you have a male cat and are considering adopting a...

cat with kitten outdoors

Dave’s Cat Food Review of 2026: Recalls, Pros & Cons

Review Summary There’s been a big push lately away from cat foods made with cheap ingredients and far too many fillers. Many cat owners are searching for healthier alternatives for their beloved pets. Some people even serve meals they prepare...

Dave's Cat Food Review

Why Do Cats Pounce? Feline Instinctive Behavior Explained (Vet-Reviewed)

Have you ever watched your cat bound around the house, seemingly jumping on random things? You may have wondered why they do it. The answer is simple: Cats love to pounce! But why? Cats pounce as an instinctive behavior and...

Cat hunting to toy mouse at home

5 Different Cat Personality Types: Understand Your Feline (Vet Reviewed)

Cats are mysterious, enigmatic creatures that do what they want to do on their own terms. It’s hard for us to imagine putting them in a box (unless it’s a literal cardboard box, of course) based on their personality. However,...

cat sitting on owners lap

My Cat Is Obsessed With Their Automatic Feeder, Should I Worry? Vet-Reviewed Causes & Facts

Cats, generally speaking, are food lovers. They become very intrigued and interested in food and are always hoping for a bit more. Given that you are reading this article, it is assumed you tried out an automatic cat feeder. But...

automatic cat food dispenser or pet feeder

Can Cats Eat Hay? Vet-Reviewed Nutrition Facts

While cats are often notoriously picky about cat food, they do seem to like nibbling on various plants and human foods. If you have hay lying around the house, don’t be surprised if your cat takes a bite or two....

Can Cats Eat Hay

Can Cats Drink Lemonade? Vet Reviewed Health Risks & FAQ

When summer hits, it’s not uncommon to have a pitcher of lemonade sitting around with which to cool off. Lemonade makes the perfect hot weather drink: it’s sweet, tart, and, most importantly, cold. But, if you’re a cat owner who...

Can Cats Drink Lemonade

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.