What's this quarter-sized black blister on my dog's lower stomach?
I am sorry to hear about your dog Molly! There are several possibilities for the area you are describing. These could include a hypersensitivity reaction to an insect bite, a bacterial infection of the skin, a fungal infection of the skin (like ringworm), an allergic reaction to something in the environment. We can also have some skin tumors appear as ulcerative areas, though these are less common. The safest thing to do is to have your vet examine the area. They may recommend additional testing such as a ringworm culture or skin cytology , or may determine just by appearance what treatment is needed. In the meantime, if she is licking at the area, an e-collar can be placed to discourage this.
Updated on September 23rd, 2025