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.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

Preventative wellness PGV mention keep cat healthy Preventative wellness PGV mention keep cat healthy mobile

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.


Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

The 10 Common Causes of Sudden Death in Cats (And Which Ones Are Preventable)

Most cat owners don’t think much about heart disease, internal hemorrhage, or viral infections until they’re staring at an empty bed. Sudden death...

Ask Dr. Paola – Help! My Cat Suddenly Has Dandruff! (March 30, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

Your Cat Keeps Vomiting After Eating: Here’s What’s Going On

Cats vomit. It’s one of the less glamorous facts of life with a feline, and most cat owners have cleaned up more than...

Ask Dr. Paola – Help! My Cat Gets Diarrhea from Wet Food! (March 23, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

More related

Is Salt Toxic to Cats? Vet-Reviewed Dangers & Limits

If you’re a person who loves flavorful food, you probably like to add a bit of salt to every meal. Salt has been...

Diabetes in Cats: Causes, Signs & Care (Vet Answer)

Diabetes mellitus, often simply referred to as diabetes, is a medical condition that results in consistently high levels of glucose (sugar) in the...

Can Cats Go Outside in the Winter? Vet-Approved Tips for Indoor & Outdoor Cats

Whether your cat can safely go outside in the winter depends on more than their personality or breed. A cat’s ability to tolerate...

Whipworms in Cats: Causes, Signs & Care Tips

Roundworms, hookworms, tapeworms, and heartworms are all common internal parasites that can cause many health problems for cats.1 Their presence in your cat’s...

Keep reading

Arm and Hammer Cat Litter Review of 2026: Recalls, Pros & Cons

Review Summary Cat litter is an essential item on any cat owner’s shopping list, and most of us have heard of Arm & Hammer, a brand that has been on shelves for over 170 years. All Arm & Hammer cat...

Arm & Hammer Cat Litter Review

How to Get Your Cat to Drink More Water: 14 Vet-Approved Tips

If you are a cat owner, you know that they love their treats and will magically appear whenever a treat bag rattles. They can also get quite vocal and demanding of your attention when it’s time for dinner! However, they...

Kitten drinking from a water bowl

Abound Cat Food Review of 2026: Recalls, Pros & Cons

Review Summary Abound cat food is sold under the Kroger brand, which provides pet store quality food at grocery store prices. The brand is touted as a filler-free food, and it doesn’t contain any corn, soy, or wheat. The Abound...

Abound Cat Food Review

Is Catnip Good for Cats’ Digestion? Vet-Reviewed Nutrition Facts & FAQ

Catnip is an herb related to mint that originated in Asia and Europe. It has green or gray-green leaves, light green stems, and tiny lavender flowers. It’s technically called Nepeta cataria and has long been used in cooking and for...

cat with green eyes in catnip

My Cat Will Only Drink from the Faucet: 5 Reasons Why

Long-time cat owners know that getting their cats to drink enough water can sometimes be a struggle. Because cats always seem to choose the strangest way to complete ordinary tasks, you’ll also find some that will drink but only from...

cat drinking from faucet

How to Tell if Your Cat Has a Double Coat: 4 Vet-Approved Tips to Help You Know

Our feline friends come in a dazzling array of coat types, colors, and patterns: long-haired, short-haired, or hairless. To keep your cat’s fur healthy and tangle-free, you’ll need the appropriate grooming tools, which differ based on what kind of coat...

persian cat lying on couch

How to Dry a Cat After a Bath: Vet-Approved Step-by-Step Guide

You rarely find a cat that will gladly accept having a bath without putting up a fight. If your cat is as apprehensive as most others, you may want to make sure you’re doing everything correctly to minimize the agony...

gray cat newly bathe

9 Best Grocery Store Cat Foods in 2026 – Reviews & Top Picks

If you are a cat owner, you know one of the most challenging aspects of raising your cat is feeding them healthy food that will provide them with the nutrients they require without upsetting their delicate digestive system. It’s even...

Siamese cat eating dry food from a bowl

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.