A red ring around a dog's mouth may be caused by a skin disease. If the dog does not clean up in time after eating or drinking water for a long time, the area around the mouth will be relatively moist for a long time, which will cause infection over time.

Treatment methods for dog skin diseases:

1. Skin diseases caused by fleas and other insects require timely external deworming, and try to avoid dogs going to the grass, etc. It is easy to come into contact with bugs again if you play in a place where you play. Dogs need to be dewormed every two months, and the dog's living environment must be thoroughly disinfected and disinfected.

2. Dogs with fungal infections need to disinfect and sterilize the environment first, including their residence and all items used. Fungi are very stubborn and very easy to spread. They can be treated with drugs such as clotrimazole ointment. , miconazole ointment, terbinafine hydrochloride spray, etc.

3. Bacterial infections are mainly caused by parasites outside the body, such as hair follicles, mites, etc. Bacterial infections can easily lead to inflammation of the dog's skin, and if not treated in time, it will become more pus-filled. If it is serious, it needs to be treated with antibacterial drugs as soon as possible. It can be used externally or through injection and infusion.