My cat’s lips are swollen

by Michael Broad · May 30, 2020

By Anonymous:

My cat’s lips are swollen. It happened suddenly. I am concerned. She was okay yesterday and as far as I can tell nothing has happened since then. She is allowed outside into the backyard which is enclosed. What do you think caused it?

Two useful tags. Click either to see the articles: Toxic to cats | Dangers to cats

Hives (Urticaria) can affect cats and people. Illustration: PoC.

Response from Michael: This may be an allergic reaction as the common cause of swollen lips, ears and eyelids is a hivelike allergic reaction called “urticaria”. I had never heard of it before I looked it up. It is a condition which can also affect people. The allergy may come from an allergen in her food, contact with an allergen, inhaling an allergen or bites and stings from insects. The swelling appears about 20 minutes after the cat is exposed to the allergen. My reference book tells me that most swellings go down after about 3-4 hours. But that clearly has not happened for your cat. Or perhaps you asked within the 4 hour timeframe. Please tell me in a comment if the swelling has subsided.

Also you should see a veterinarian if they are seeing patients during the coronavirus crisis. I think it qualifies as an emergency so I’d expect them to see you. Your vet will want to know the likely allergen so try and figure out what it might be. He might administer adrenaline or an antihistamine.

Useful links
Anxiety - reduce it
FULL Maine Coon guide - lots of pages
Children and cats - important

It is a more serious reaction if there is also wheezing, breathing difficulties, diarrhea and vomiting. A possible cause is a snake bit in which case an urgent visit to the vet is called for.

Another possibility is an inflammation of the lips which is called “cheilitis”. Inflammed lips are often caused by a mouth infection that has spilled over into the lips. Or it might be due to contact with the vegetation e.g. weeds that your cat has come into contact with which has irritated the lips. It can also be caused by chewing on a live wire.

A third possibility is a yeast infection. But this is a long shot and it occurs slowly and therefore would not apply to this case it seems. It is called “malassezia pachydermatitis”. It is an overgrowth of yeast normally found on cats. See a vet about this.