My dog's lip has a cut that won't heal. Is it an infection or mass?

Honestly it could be either caused by the infected tooth or it could be a mass. This is why your vet first prescribed antibiotics to see if it goes down or not. Now this is the nerve racking wait and see period to determine if is something to worry about and requires a biopsy once the antibiotics have run their course.

It could be an infection, cyst, or a mass. Have your vet take a look at it to determine the exact cause. Your vet can do a needle aspirate to diagnose and then determine the best way to treat. She may need an antibiotic, anti-inflammatory, or it may need to be removed.

From the picture it actually looks more like a deep skin infection to me. This could be bacterial or fungal, or even a hypersensitivity reaction (less likely). I would recommend that she be examined by your veterinarian soon. They may look at a sample under the microscope to help determine what therapies might be most helpful. Best of luck and I hope she improves soon. Thank you for using Pet Coach.

From the picture, I'm concerned that he may have a mass -- or it could be the way his skin hangs that looks like a mass. Either way, the area looks very irritated and would be suspicious of a superficial skin infection that is causing discomfort. I Would recommend getting him to a vet today for evaluation and starting on antibiotics if needed, or sampling the mass if there is indeed a mass within that area.

Hi. Good photo. I'm concerned about this area. It looks raised and mass like rather then an infection. There are benign and cancerous masses of the skin. It may be a deep infection as well. It is hard to say. I would recommend an exam and a cytology of this area. This will help us find out the type of cells this is made up of. Good luck

This looks very inflamed and given the severe itching/licking I recommend an urgent physical exam and skin check to rule out infection and identify the underlying trigger such as allergy or immune mediated disease. Referral to a dermatology specialist and biopsy may be worthwhile

Hi and thanks for posting on Petco Pet Education Center, formerly Petcoach! It is hard to get an idea of what the spot is on the bottom lip without examining Otis first. It could be a bacterial or fungal infection, or a mass/tumor. I would recommend having your veterinarian take a close look at it. They may need to take a sample of the lesion to determine what it is and if it is cause for concern or not. Antibioitcs or antifungal medication may need to be prescribed. I hope this helps and best of luck to you and Otis!