What if my cat has a swollen mouth, is drooling, and lethargic?

Poor SoCo sounds extremely ill, and the symptoms you are describing are a medical emergency. As a senior cat, he could have many things wrong with him including dental problems, diabetes, kidney failure, hyperthyroidism, liver failure, or cancer among others. He needs veterinary care now to diagnose what is causing all his symptoms so he can be treated. Please take him into an ER vet clinic; if there isn't one in your area, there will be a vet on call for emergencies. The information to reach that vet is found on a clinic's answering machine or website.

There are some contagious viruses such as calicivirus that can cause ulcers in the mouth along with other upper respiratory signs such as sneezing and nasal discharge. It is also possible that both cats were exposed to a toxin or something caustic that injured their mouths if they go outdoors or have access to any chemicals. If their symptoms have been present for more than 24 hours I'd recommend taking them to an emergency veterinarian. They can examine both cat's mouths to look for problems and determine whether or not they may be dehydrated from not eating or drinking.

Hello, it looks like an abscess, probably a tooth abscess, it's an emergency as he is not eating, take him to the emergency vet as soon as you can today, the abscess will need to be drained under anesthesia first, then a course of antibiotics will be given.

Although a picture of it would help to determine the underlying cause more specifically, this presentation seems to be likely related to a tooth abscess/infection. A clinical examination at your local veterinarian is essential to confirm these clinical suspicions and treat appropriately. Antibiotics may be needed. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. Please find the time to give us a feedback about the consultation as that will be used to improve our service.

This is an emergency. Your kitty could have a severe allergic reaction, or a snake bite or serious injury (maybe because of a collision with a car). He needs to be seen by a veterinarian right away. Please take him to a PetEr right now as this sounds life-threatening.

I am sorry to hear about Blue. One thing we worry about in male cats exhibiting this behavior is a urinary blockage. It can make them lethargic, vomit, not eat, painful (drooling can be a sign of pain). If you aren't sure he is urinating normally or if you press on his lower belly and he is painful then we would be very concerned this could be his issue and this is a medical emergency and he should be seen right away.

Thank you for submitting your question regarding Korra. I recommend that she sees a veterinarian as soon as you are able. The lip is swollen and possibly ulcerated. This is likely uncomfortable for her. The veterinarian will examine her especially looking inside the the mouth. She could have further wounds in her mouth or even a bad tooth. Treatment will be started based on these findings. I do not believe an over-the-counter medication will help. Do not give any over-the-counter pain medications either as they are toxic to cats. I hope this information helps!