Editor’s Note: NaturalPetsHQ.com is supported by readers and may earn for purchases made through links in this post.

The tissues around a cat’s mouth are exquisitely sensitive and contain complex structures to help your kitty navigate his world. There are multiple kinds of hair, glands, and skin not to mention the teeth and tongue.

It’s not always easy to see an abnormality inside the mouth but when a cat’s lip is swollen, it’s pretty easy to notice. 

The most common cause of top or bottom lip swelling in cats is eosinophilic granuloma related to allergies. However, there are many other problems that can show up in the area. Parasites, immune-mediated disease, dental problems, and toxins can also cause a cat to have a swollen lip. 


  • Lip swelling is a common symptoms in cats.
  • Allergy is the most common cause of swollen lips in cats.
  • Treatment is effective in most cases with the help of a veterinarian.

Symptoms Associated with Swollen Lip in Cats

As soon as you notice something abnormal around your cat’s upper or lower lip area and/or mouth try to investigate further. You’ll often find more than just lip inflammation. Check for:

  • Swelling of the edge of the lip 
  • Ulcer or scab on lip
  • Red gums 
  • Noticeable mass/growth
  • Hair loss around the mouth
  • Inflamed bumps on face/head
  • Itchy on the entire body
  • Big chin
  • Redness of lips
  • Bleeding or oozing of fluid/pus
  • Bad smell from mouth
  • Gums red at the edge next to the teeth
  • Itchy face/mouth
  • Shaking the head a lot
  • Decreased eating
  • Changes in drinking habits
  • Dropping food/chewing strangely
  • Rubbing face with paws or on objects
  • Gagging
  • Exaggerated swallowing
  • Drooling
  • Enlarged lymph nodes between the lower jaw & neck


Why Is My Cat's Lip Swollen???

Causes of Feline Lip Swelling

What is eosinophilic granuloma complex (EGC) in cats?

Also known as EGC, feline indolent ulcer or “rodent ulcer,” this inflammatory skin condition is common in cats. Typical EGC lesions appear as a puffy, swollen top or bottom lip. Cats can also develop skin ulcers and inflammation on their feet, legs and bellies. 

cat's lip is swollen
Typical reddish swelling on a cat’s lip

Eosinophils are immune system cells that is activated in allergic responses. These cells flock to the affected area and cause swelling as they try to fight off an invader. The most common causes of allergic reactions in cats include:

  • Food allergy
  • Contact allergy (especially from a food dish)
  • Flea bite allergy
  • Mosquito bite hypersensitivity
  • Atopy (pollen)

While veterinarians do have ways to test for some allergies, sometimes it’s a matter of removing exposure to various things and waiting to see if the allergic reaction and lip swelling improve. 

An easy thing you can try right away is changing the type of food dish you use for your cat. Plastic and stainless steel dishes are more likely to cause a skin reaction in cats. No matter what kind of food dish you use, start washing it with hot, soapy water between EVERY meal. 

Demodex Mites

Demodex is a mite that parasitizes the skin and hair follicles of many animal species. Cats have two known types-Demodex cati and Demodex gatoi along with one unnamed type. 

Lesions may appear anywhere on a cat’s body, including their top and bottom lips. It’s not unusual for cats to have hair loss, small scabs and swelling as a result of Demodicosis.

Demodex mites don’t always cause problems, in fact, many normal cats may harbor a few D. cati mites. D. gatoi mites are less common and unlike D. cati, they can be spread between cats. 

More from Natural Pets HQ

Learn more about demodectic mange in cats

Yellow and white cat with scabs on face (demodectic mange in cats)


Pemphigus is an immune-mediated disease in which the connections between skin cells are destroyed. The symptoms of pemphigus include sores, pus-filled blisters and swollen skin frequently seen on the lips but possibly anywhere on the body. This skin disease is often made worse when a cat spends time sunbathing.

Examination of a biopsy sample is the best way to diagnose pemphigus in cats. In most cases, there is no identifiable cause (1). Different forms of pemphigus respond variably to therapy. 

Oral Tumors

Various tumors can affect the tissues of a cat’s oral cavity and cause the appearance of lip swelling. Tumors may be benign or cancerous and it’s impossible to differentiate the two without a biopsy in many cases. (2)

Squamous cell carcinoma, fibrosarcoma and malignant melanoma are the most common mouth cancers found in cats. All three carry a poor long-term prognosis. 

Skin Tumor

Cancers of the skin occasionally start around a cat’s mouth area. Mast cell tumors and cutaneous lymphoma can both cause a lesion that might look similar to more benign causes. Diagnosis is best made by biopsy. 

Dental Disease

Teeth problems are extremely common and increase as cats get older. As a veterinarian, I see the gamut in oral problems from just a little gingivitis to stomatitis and tooth resorption. Sometimes the inflammation is so severe it can cause lip swelling, too. 

The only way to fully diagnose dental problems is with a thorough oral examination and intraoral radiographs. Anesthesia is required to accomplish this, but your cat will thank you in the end. Don’t fear anesthesia–it’s come a long way in the last 20 years and many safe options are available. 

Discuss your concerns and fears with your vet so you can feel confident about helping your cat with dental disease. 

intraoral radiographs for dental disease and oral tumors
Oral x-rays help diagnose dental disease and tumors


Skin infections sometimes affect the tissue of the face and lips. Bacterial infections and abscesses from Staph and Pasteurella are more common in cats who spend time outdoors. Fighting with other cats and other kinds of trauma are often the culprit.

Fungal infections like ringworm cause hair loss, red skin, and sometimes crusting. I’ve seen cats with crusty ears, noses, and lips from ringworm infections. A simple skin culture will help diagnose ringworm. 

Chin Acne

Should we call it “chacne?” In any case, feline chin acne is just what it sounds like–follicles on the chin area become plugged and inflamed. It usually looks like blackheads, dirty fur, reddish skin and sometimes a puffy lower lip. 

Cat chin acne is often related to allergies and some of the same treatment methods are used. 

Chewing Pothos can cause a cat's lips to swell
Pothos is a common houseplant


Pothos Scindapsus and Epipremnum are tropical house plants that belong to the Araceae family. If chewed or ingested by a cat, Pothos can cause significant swelling of the cat’s mouth, lips and gastrointestinal tract.

It’s a good idea to avoid having Pothos and cats in the same home. If you want to have both, make sure the plant is in an area the cat doesn’t have access to. 


Before you take your kitty to see the vet, look around the house and see if you can collect more clues for your vet. Has your cat been eating and drinking normally? Any changes in litter box habits? Have you changed her food, toys or bedding? Have you ever seen these symptoms before?

Your veterinarian might want to do some testing before treating your cat’s lip problem. These tests might include:

  • Skin Scrape
  • Fungal culture
  • Bacterial culture
  • Allergy testing
  • Biopsy
  • Radiographs
  • Blood Tests
  • Medication Trial
  • Food Trial


It’s important to try to identify the underlying cause of a cat’s lip swelling, but it’s not always possible to get a definitive diagnosis. Your vet will make a recommendation for treatment based on what they find out. 

A brief summary of treatments for the problems I covered above:

  • Allergy/EGCoral or injectable steroids, Atopica/cyclosporine,  flea/mosquito control, food trial with hypoallergenic food like Royal Canin HP. 
  • Demodex– topical anti-parasitic medicine Bravecto, or ivermectin injections.
  • Chin Acne-similar to allergy treatment plus cleaning skin, benzoyl peroxide to flush follicles.
  • Dental Infection– clean all teeth, radiograph and extract abscessed teeth, antibiotics.
  • Oral Tumor– radiographs, biopsy, surgical removal, radiation treatment.

Cost of Veterinary Care for Swollen Cat Lips

As for cost, it really depends on whether there are other symptoms besides an inflamed lip. You may end up spending between $100 and $300 for an uncomplicated case of skin allergy or infection. It could cost up to several thousand for to diagnose and treat recurring skin disease, dental disease or tumors. 


You should not assume your cat’s lip is swollen due to EGC. There are so many other causes that can cause identical symptoms. 

Let your vet take a look and recommend the next step. The proper diagnosis and treatment will save you money and time, not to mention getting your cat back to normal quicker!

The content provided on NaturalPetsHQ.com is for general information only. It is not meant to replace individualized medical advice from your own veterinarian. Read more on the Privacy Policy and Terms of Use page.


  1. Scott DW, Miller WH, Griffin CE.: Immune-mediated disorders. Muller and Kirk’s Small Animal Dermatology, 6th ed. Philadelphia, WB Saunders 2001.
  2. Stepaniuk KS: Identifying and Treating Oral Tumors in Practice. Chicago Vet Conference 2019.

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API