Evie peeled a $1.29 metal cat-food can at 7:00 p.m. in Seattle. Moss, her 10-lb tabby, licked the lid edge, then the bowl. By 8:15 the lower lip looked puffy on the left, like a bee sting. Moss still ate. She did not paw her face. A sharp can rim can cut. Some cats react to a flavor or to metal contact. Eosinophilic granuloma complex can swell a lip into a shiny, raw pad and needs a veterinarian, not a squeeze. Do not lance it. Do not put cream from the bathroom cabinet on it. Book a visit if the swelling spreads, Moss stops eating, or strings of drool start. Photograph the lip next to a penny so the clinic can see the size.
Key points at a glance
- A swollen lower lip after a metal can may be a cut, a contact reaction, or eosinophilic granuloma.
- Do not squeeze, pop, or "drain" the lip at home.
- Switch to a can opener and a ceramic dish so she cannot lick a raw lid.
- Vet the same week if it is not shrinking; sooner if she will not eat or drools.
- Spreading swelling, ulcers, or a cat who hides is not a wait-and-see bump.
Cut, allergy, or eosinophilic disease
Cheap pull-tabs leave a razor edge. Moss licking the $1.29 lid is a classic nick. A small cut puffs. It should not balloon across the chin overnight. Look for a puncture or a dark crust. Blood on the can is a clue.
Food or contact allergy can swell a lip after a new flavor. Eosinophilic granuloma complex—sometimes called a rodent ulcer when it hits the upper lip—can also thicken the lower lip into a firm, pink, hairless plaque. That is immune-driven. It will not vanish because you switched bowls once.
Hands off. Food in a safe dish.
Scoop food into a plate. Toss the lid. Do not let her "clean" the can. If the lip is only slightly puffy and she eats, you can watch 24 hours while you book. If she drools, drops food, or the puff doubles, go in. The clinic may need a look under the lip, dental check, and sometimes a sample. That is their call.
Skip steroid cream from a person in the house. Skip squeezing "to get the pus out" when you have not confirmed pus. You can seed infection and make granuloma worse. Pain that stops eating is a same-day problem in cats.
| After the 7:00 p.m. can | More likely | Act |
|---|---|---|
| Small puff, still eating, lid was sharp | Cut / irritation | No squeeze; ceramic dish; recheck 24h |
| New flavor, lip puffy both sides | Possible allergy | Stop that recipe; call the clinic |
| Shiny, raw, or growing plaque | Eosinophilic granuloma | Veterinary exam |
| Drool, not eating, spreading swell | Pain / infection / worse lesion | Same-day vet |
| Face swelling beyond the lip | Allergic or serious infection | Emergency if breathing changes |
Evie moved Moss to a plate, threw out the licked lid, and photographed the lower lip before bed. This page is general education, not a diagnosis; ask your veterinarian if a swollen lip spreads, stops eating, or comes with drool.