Why are my cat’s lips Swollen? 7 Possible Causes

Why are my cat’s lips Swollen?: 1. Allergies 2. Insect bites 3. Dental infection 4. Injury 5. Abscess 6. Autoimmune issues 7. Food reaction.

Why are my cat’s lips Swollen?

If your cat’s lips look swollen, red, or irritated, it can be worrying. Swollen lips in cats are usually a sign of an underlying issue like allergies, infections, or injuries. Since cats cannot describe their discomfort, noticing these changes early helps you protect their health.
Below are the 7 most common causes of swollen lips in cats—and how to understand what each one means.

Quick Overview Table

Possible Cause	What You May Notice	What It Means
Allergies	Redness, itching	Reaction to food, dust, plastics, plants
Insect bites	Swelling on one side	Reaction to bee, ant, mosquito bites
Dental issues	Bad breath, drooling	Gum infection or tooth problem
Feline acne	Black spots on chin/lips	Blocked hair follicles causing swelling
Injury	Cuts, scratches	Cat fight or hitting something
Stomatitis	Mouth pain, drooling	Severe mouth inflammation
Eosinophilic granuloma	Raised swollen bump	Immune reaction, common on lips

1. Allergies

Food allergies, dust, cleaning sprays, and even plastic bowls can cause lip irritation.
Cats with allergies may also show:

• Itching
• Sneezing
• Face rubbing

Switching to stainless steel bowls and avoiding scented cleaners often helps.

2. Insect or Bug Bites

A sting from a bee, ant, wasp, or mosquito can cause sudden swelling on one side of the lip.
These bites are usually painful but improve within 24–48 hours.

3. Dental or Gum Problems

If your cat has gingivitis, tooth abscess, or mouth infection, the lips may swell.
Other signs include:

• Drooling
• Difficulty eating
• Bad breath

Dental issues need quick treatment to avoid worsening pain.

4. Feline Acne

Black dots or bumps on the chin and lips are signs of feline acne.
This irritation can cause swelling and redness.
Often triggered by:

• Dirty food bowls
• Stress
• Hormonal imbalance

Clean bowls daily and use non-plastic dishes.

5. Injury or Trauma

A scratch during play, a fall, or running into furniture can cause lip swelling.
Injuries generally show:

• A cut or scab
• Swelling in one specific spot
• Sensitivity to touch

Minor injuries heal on their own, but deep cuts need attention.

6. Stomatitis

Stomatitis is a painful inflammation inside the mouth that can push swelling outward to the lips.
Signs include:

• Difficulty eating
• Drooling
• Bad breath

This condition requires veterinary help.

7. Eosinophilic Granuloma

This is an immune-related condition that causes raised, swollen, pink or yellow bumps on the lip.
It is common in young cats and often appears suddenly.
Triggered by allergies or immune reactions.

Summary Table

Cause	Severity	Needs Vet?
Allergies	Mild–Moderate	Sometimes
Insect bite	Mild	Only if severe reaction
Dental issues	High	Yes
Feline acne	Mild	Not always
Injury	Mild–Moderate	If deep
Stomatitis	High	Yes
Eosinophilic granuloma	Moderate	Yes

FAQs

1. Is lip swelling in cats serious?

It can be, especially if caused by infection, dental issues, or immune diseases.

2. Can food allergies cause swollen lips?

Yes. Cats can react to certain ingredients, bowls, or environmental triggers.

3. Should I take my cat to the vet for swollen lips?

If swelling lasts more than 24 hours or the cat is in pain, yes.

4. Can insect bites cause one-sided lip swelling?

Yes, sudden swelling on one side often indicates a sting or bite.

5. What if my cat also has black spots on the chin?

This is likely feline acne, which can cause lip swelling.