Is your cat’s lip swollen?  This can be due to many different reasons.  Sometimes this will quickly go away, but this could be an early sign that your cat has something more going on.  There are a few things that you can try at home at first, but if your cat’s lip does not quickly improve, it would be best for your cat to see your vet.

Why is my Cat’s Lip Swollen?

  • Eosinophilic Granuloma Complex
  • Skin Cancer
  • Chin Acne
  • Dental Issues
  • Allergies
  • Bug Bites

These are a few common reasons that your cat’s lip may be swollen. Some of these will go away after a day or two, but many will stay around for a long time. 

If your cat’s lip does not just go away the next day or seems to be getting worse, it would be best for your vet to see them see why their lip is swollen.

6 Common Reasons that Your Cat’s Lip Maybe Swollen

These are 6 common reasons that can cause your cat’s lip to get swollen

Eosinophilic Granuloma Complex

Eosinophilic Granuloma Complex is also called a rodent ulcer.  This causes your cat’s lip to be very swollen and ulcerated. 

While the cause of this disease is unknown, it is believed to be caused by allergies, autoimmune diseases, feline leukemia, fleas, bacterial or fungal infections.

Your vet can easily diagnose this condition in your cat.  This can be treated depending on what is causing this in your cat. 

Common things needed to help treat Eosinophilic Granuloma Complex are:

  • Flea and tick prevention
  • Limited ingredient diets
  • Antibiotics
  • Anti-inflammatories

While these can look very bad, they usually are benign causes of lip swelling that your vet can help you treat and control.

Skin Cancer

Cats can get cancer on their face and lips.  This is commonly seen in white or light-faced cats.  You may notice that their lip is swollen because they have cancer. 

This would also be ulcerated and have a very hard time trying to heal.

Common types of skin cancer seen on cat’s face are:

  • Squamous Cell Carcinoma
  • Melanoma
  • Mast Cell Tumors

If your cat has a swollen or ulcerated lip, your vet may want to take a small sample from this area to see if there are cancer cells present. 

If your cat does have cancer on their face or lips, there are chemotherapy and radiation options for your cat. Many of these will have to be done at a veterinary specialty center with a veterinary oncologist.

Chin Acne

Cats can commonly get acne on their chin that extends to their bottom lip.  You will see black and red spots on their chin.  Your cat may even be rubbing their face causing it to be raw and infected. 

There are many causes of chin acne in cats, such as:

  • Allergies
  • Unclean food and water bowls
  • Ingrown chin hairs
  • Bacterial and fungal infections

If your cat has chin acne, you can try washing their face every day with a gentle shampoo or even using a baby wipe to help keep this area clean. 

Also, switching types of bowls your cat is using.  Plastic bowls tend to cause cats to develop chin acne more frequently than glass or ceramic bowls

Dental Issues

If your cat has dental issues, they can have a swollen lip.  Infected teeth and gums can cause inflammation that extends to the tissue under your cat’s lip, causing their lips to look swollen. 

You can easily look inside your cat’s mouth to see if their gums are red and inflamed.  Some dental issues cause your cat’s teeth to grow at abnormal angles, and they may even have a tooth that is poking them in the lip. 

Your vet can help clean your cat’s teeth and start them on antibiotics to help with any dental infection that your cat may have.


Allergies commonly will cause your cat’s lip to be swollen.  They may have injured their face, pawing at it because it itches from the allergies. 

They may even have gotten stung by a bee or other insect in their face causing their lip to swell. 

Allergies are not the most common cause of lip swelling in cats but can happen.  Your vet can prescribe anti-inflammatory and allergy medication for your cat to help decrease this swelling.

Bug Bites

If your cat spends a lot of time outside, they may have gotten bitten by a bug.  Bees, snakes, and other bugs are very intriguing to most cats.  They will commonly chase after these insects and get bit or stung in their face. 

This would cause your cat’s face to become swollen.  Many times, this type of swelling will quickly get better with just some antihistamines such as Benadryl. 

You can give your cat Benadryl if you think that they got stung in the face.  The typical dosage used for cats is 1mg per pound twice a day.  This is essentially ½ adult Benadryl tablet twice a day.


If your cat is known for getting into things they should not have, they may have fallen and hit their face on the floor.

While most cats do land very easily on their feet, some will get caught in something on the way down, causing them to hit their face.  This can cause their lip to be swollen and even cause their face to bleed.

What To do to help my cat with lip swelling

If your cat’s lip is swollen, it is best not to ignore this as it could be the beginning signs or something more severe.  These are a few things that you can try at home to help.

Wash your cat’s face

At home, you can try to keep this area clean by washing your cat’s face.  Using baby shampoo mixed ½ shampoo, and ½ water will help keep your cat’s face clean without you having to give them a full bath. 

After using the soap/water mix, you can just wipe the soap off with a washcloth with just water.

Change Bowl types

Sometimes it is the bowl that is causing your cat to have a swollen lip.  If you are using a plastic bowl, try switching to a metal, glass, or ceramic bowl. 

Also, make sure that you are cleaning your cat’s bowl every day.  Bacteria and other allergens can quickly build up on your cat’s bowl, causing your cat to develop a swollen lip.

Feed a Hypoallergenic diet

Some cats’ do have food allergies, and this may cause a swollen lip.  If their swollen lip continues, you can try feeding a hypoallergenic diet or a limited ingredient diet.

Many of these can be found at your local pet store.  Some will need a prescription from your vet.

See your vet

If your cat’s lip is very swollen and ulcerated, your cat will need to see your vet.  They can examine your cat to see why their lip is swollen. 

They may need to take small samples of this area to look for cancer or do other diagnostic tests.  Your vet will be able to prescribe your cat antibiotics and anti-inflammatory medications. 

Cat’s Lip is Swollen

Final Thoughts

Your cat’s swollen lip may easily go right back down after a few days.  There are many reasons for this swollen lip.

Many are not very serious.  If your cat’s lip looks infected or is quickly getting worse, it would be best for your vet to see your vet.

They can assess what is causing your cat’s lip to be swollen and get them started on medication to help right away. 

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