I have a 6 lb rat/chi mix that just developed a blister type mole on her back in the last week. It seems to have gotten bigger in the last couple of days. What is this? Pet's info: Dog | Mixed Breed | Female | spayed | 1 year and 1 month old | 6 lbs

I’m not sure if there was supposed to be a photograph attached to your post, but that would be helpful. Red raised masses can be something like infection or an ingrown hair. They can also be more indicative of a skin tumor. Of the skin tumors, most are benign but there is one called a mast cell tumor which is cancerous and needs to be removed quickly. When in doubt, I always recommend to have any type of skin mass examined by the veterinarian. Sometimes they can tell what it is based on exam. But just like with humans, not all skin tumors can be identified just by looking. The doctor may need to aspirate some of the cells to look under the microscope. That is the only way to accurately know what kind of tumor it is. I always recommend to play it safe with something like this! I hope this is helpful and please feel free to post any additional questions.

From the photo, that looks almost like a mass. I recommend to have it examined by the veterinarian as red, hairless masses are concerning for a skin cancer called a Mast Cell Tumor. The doctor will palpate the lesion and will likely recommend to aspirate the cells if they suspect a mass. Gambit should also wear an elizabethan collar to prevent him from licking the area as this can make it worse. It’s best to play it safe and have it checked out. I hope this helps and please feel free to post any additional questions.