Why Is My Cat's Lower Lip Swollen?

Cats are masters of emotional manipulation. However, if one day you notice that Muffin looks more than acts like she's pouting, there's likely to be a medical cause. A protruding lower lip on a cat isn't part of a sulking act; it's a symptom that needs a doctor's care. Whether your cat's swollen lower lip is from an allergy, dental problems or is actually a tumor, your vet is the one who can diagnose the problem and recommend treatment.

Veterinarian at work
Let the vet determine how serious Muffin's swollen lip is.
credit: KatarzynaBialasiewicz/iStock/Getty Images

Eosinophilic Granuloma Complex

Sometimes a cat's immune cells malfunction and react as if parasites have invaded the cat's body. These particular immune cells are called eosinophils. The University of Cornell College of Veterinary Medicine says the condition that results is termed eosinophilic granuloma complex. Usually, it's caused by an allergic reaction to a parasite bite, such as from a mosquito, flea or mite. If your kitty is bitten by one of those pests on or near her lower lip, it could swell, appear red and itch.

Dental Abscesses

Muffin's swollen chin could be caused by a dental abscess or other tooth problem. In her article for Veterinary Partner, Jan Bellows, D.V.M., explains that an abscessed or broken tooth or other infected sore in a cat's mouth will cause swelling of her lips or face. If an oral issue is the problem, you might notice other signs, too. A painful mouth makes it difficult to eat; Muffin might seem to lose her appetite. Irritable reactions when you rub or scratch her chin, drooling, head shaking and worse than normal "kitten breath" are all signs that Muffin's swollen lip could be caused by a problem in her mouth.

Other Issues That Cause Swelling

If Muffin's teeth are fine and it isn't mosquito season, there are plenty of other medical issues that could cause her lower lip to swell. Feline acne is a condition that causes swelling of the lower lip and chin when pores are blocked by sebaceous glands under the chin. WebMD says that a cat's lips, face or entire head could swell up as a result of an allergic reaction to anything from pollen or other inhaled allergen. Sometimes food or even medications such as antibiotics or heart medications can cause an allergic reaction, according to the University of Cornell College of Veterinary Medicine. If Muffin took an awkward tumble and landed on her chin, the physical trauma could cause swelling. A particular type of cancer that causes oral tumors can make a cat's lower jaw and lip swell. It's called oral squamous cell carcinoma according to Veterinary Partner, and usually occurs in older cats.

Act Immediately

When you notice any physical abnormality in your cat, an immediate trip to the vet is a wise move. Always consult an experienced veterinarian regarding the health and treatment of your cat. The doctor can pinpoint the cause of the swelling and prescribe medication and treatment to alleviate discomfort. If the swelling is due to an allergic reaction, the allergens can make breathing difficult for your kitty and can result in anaphylaxis, which is life-threatening. If left untreated, broken teeth and other oral problems can result in further oral issues as well as heart, liver and kidney disease. There's no such thing as a wasted trip to the vet, especially when your kitty's health is at stake.