Cat Swollen Lip:  Why Does My Cat Have a Swollen Lip?


Why does my cat have a swollen lip?  If you’re asking this question, you’re understandably concerned about your precious kitty.  We love our cats like family, and when something isn’t right, we want to quickly help them get back to their normal and healthy selves.  So, what causes a cat swollen lip, and what should you do about it?  Continue reading, and I’ll share some of the most common causes for a cat swollen lip, as well as how to treat cat swollen lip.

Why does my cat's mouth look swollen?

Table of Contents

Other Symptoms Often Present with a Swollen Lip in Cats

Many times, when a cat has a swollen lip, there may be other symptoms present as well.  Looking for these other symptoms can help you give a full picture to the veterinarian.  A few other symptoms to look for include:

  • Scabs and sores
  • Red gums
  • Oozing
  • Bleeding
  • Drooling
  • Masses or growths
  • Hair loss
  • Foul odor in mouth
  • Itchy face or mouth area
  • Ulcers
  • Gagging
  • Decreased appetite
  • Head shaking
  • Rubbing paws on face
  • Enlarged chin

Causes Of Swollen Lips in Cats

What does swollen bottom lip on a cat mean?  If you’re curious why your cat’s lip is swollen, unfortunately, there isn’t one simple answer.  There are actually a number of possible reasons why a cat has a swollen lip.  I’ve laid out these potential reasons in the next few sections.

Eosinophilic Granuloma (EGC)

Eosinophilic Granuloma, or EGC, is one of the potential reasons your cat’s lip is swollen.  This condition, which may also be referred to as feline indolent ulcer or rodent ulcer, is caused by an allergic reaction.  The allergic reaction activates the eosinophils, a special type of white blood cell.  When activated, the eosinophils migrate to the area that was affected by the allergic reaction to try to fend off the reaction.  

All the cells concentrating in the same area can result in swelling.  If you are seeing cat swollen lip white spots, it may be EGC.  

EGC cat swollen lip flea allergy is one possible cause.  If a cat is allergic to the flea bite, it can activate the eosinophils and cause the swelling.  Some other potential causes of allergic reactions that can result in EGC include:

  • Food allergies
  • Hypersensitivity to mosquito bites
  • Pollen (atopy)
  • Contact from an allergen (often a food dish)
cat swollen lower lip


For a cat sneezing and swollen lip, it could be caused by allergies.  Some cats are allergic to dust, pollen, food, and other items in their environment.  These allergens don’t always result in EGC, but they may still cause your cat’s lip to swell.  Some other allergy symptoms to look out for include sneezing, coughing, wheezing, rashes, red eyes, licking the lips, and a runny nose.


Pemphigus might also be the cause behind a cat swollen lower lip.  This disease causes skin cell connections to be destroyed.  Once these connections are destroyed, it can cause swelling, scabs, pustules.  

With Pemphigus, you may notice these symptoms around the lip, but you might also notice them on other areas of your cat’s body as well.  Your vet will need to perform a skin biopsy to diagnose pemphigus.

Demodex Mites

If you’re asking, “why does my cat have a swollen bottom lip,” Demodex mites may be to blame.  Demodex mites can live on a cat’s skin and within their hair follicles.  While Demodex mites can often live on a cat without causing any real issues, they do cause issues sometimes.  Demodex mites may cause scabs, hair loss, or swelling.  In most cases, the swelling that results from Demodex mites will be relatively mild.

Dental Disease

Dental diseases, such as periodontal disease and tooth resorption, may also cause lip swelling.  Both of these conditions can cause inflammation on the gums.  However, in some more severe cases, the inflammation may be severe enough that it causes the cat’s lips to swell.

If your cat has dental disease, the vet will need to perform a teeth cleaning.  They will also need to remove any abscessed teeth.  Dental cleanings for cats require anesthesia.  However, you shouldn’t be too concerned since anesthesia is commonly used by veterinarians and they’ll be monitoring your cat the whole time to keep her safe.

Watch this video to identify some other symptoms to dental disease in cats.

Skin Infections

A skin infection can also be the underlying cause for a cat’s swollen lip.  One common type of skin infection is a bacterial infection.  Bacterial infections, like Staphylococcus, more commonly occur with outdoor cats. This is due tot he fact that bacterial infects are often cause by trauma or a wound.

Fungal skin infections may also cause a cat’s lip to swell.  Ringworm and other types of fungal infections can also cause a cat to lose hair and have red or crusty skin.


Why does my cat’s mouth look swollen?  If your cat fell recently, they could have injured their mouth.  If this is the case, their teeth and/or mouth interior may also have injuries that require treatment from their veterinarian.

my cat has a swollen lip what can i do

Oral Tumors

Notice cat swollen upper lip one side?  It might be an oral tumor.  Some of the different types of oral tumors that can affect the oral cavity of a cat include malignant melanoma, fibrosarcoma, and squamous cell carcinoma.  If your cat has one of these tumors, it may make it appear that their lip is swollen.

Your vet will need to perform a biopsy on the tumor to determine whether it is cancerous or benign.

Skin Tumors

If you’re asking, “what is this lump on my cats lip,” it could be a skin tumor.  Sometimes skin cancer begins on the areas around a cat’s mouth, which can make it look like their lip is swollen.  If you suspect your cat has a tumor, you will want to bring them to the vet as soon as possible.


Some houseplants are toxic to cats.  For example, if a cat chews on Pothos Scindapsus, it can cause their mouth and lips to swell.  Pothos can also cause swelling in the gastrointestinal tract, which obviously could be very serious for your cat.  If you like having plants in your house, be sure to choose ones that are safe for cats.

If you enjoy houseplants, this video can help you choose feline-friendly options.

Chin Acne

Why is my cats bottom lip swollen?  The culprit may be chin acne.  Chin acne occurs with the follicles on the cat’s chine get clogged and become inflamed.  Chin acne is often easy to spot; it causes the skin on the area around the chin to look red, can make a cat’s fur look dirty, and often includes visible blackheads.  In most cases, chin acne is the result of an allergy.

Determining the Cause of Your Cat’s Swollen Lip

Before thinking about cat swollen lip home remedy ideas, it is important to first determine the cause of your cat’s swollen lip.  Your cat’s vet is the best resource to help you with this.  They’ll also be able to help recommend the best treatment options based on the exact cause of the swelling.

However, before rushing off to the vet, consider if there are any other symptoms you have noticed.  Giving your vet a full picture of what is going on will make it easier for him or her to diagnose the problem.

Depending on what your veterinarian notices during the checkup, they may perform a variety of tests on your cat or his lips.  These test may include:

  • Bacterial culture
  • Fungal culture
  • Skin scrape
  • Biopsy
  • Radiographs
  • Allergy testing
  • Blood tests
  • Food trial 
  • Medication trial
treatment for cat swollen lip

Treating a Cat’s Swollen Lip

My cat has a swollen lip what can I do?  As I just mentioned, the best treatment for your cat’s swollen lip will depend on the underlying cause of the swelling.  Your cat’s vet can help you diagnose the problem and will recommend an appropriate treatment.

Here are a few possible treatment options they may recommend for some of the more common causes of swelling:

  • Dental infections:  Dental cleaning, tooth extractions as needed, antibiotics  
  • Tumor:  Biopsies, removal, radiation
  • Allergies or EGC:  Steroid treatment, flea treatment, switching to a new food
  • Chin acne:  Cleaning skin, flushing the follicles with benzoyl peroxide, similar treatments to those for allergies
  • Demodex mites:  Spot-on mite treatment medication

Cat Swollen Lip: Closing Words

Noticing that your cat has a swollen lip can lead to a lot of worry and concern.  Hopefully I’ve helped you identify some of the possible causes for the swelling.  Remember, your cat’s vet can help you get to the root of the problem and recommend the specific treatment necessary to get your cat back to their normal and happy self.

grey cat licking paws


Will a swollen lip go away on its own?

Swollen lips may or may not go away on their own.  It will all depend on the underlying cause of the swelling.  If your cat has a swollen lip that doesn’t resolve itself quickly, you should schedule an appointment with the vet to determine the cause of the swelling.