My pet rat had one underneath her ear. I thought it was because her and my other rat were fighting, but I still don't know. If you gently clean it with some warm water on a washcloth and then put a little dab of neosporin, it should go away soon. It helped my rat, and the bump was gone within a few days :}
My Pet Rat Has A Large Round Bump On Its Cheek. I Am Worried It Could Be A Facial Tumour. My Mum Thinks It Might Be A Insect Bite, I Will Be Posting Photos Soon. Can You Help Me?
This could be a cancer or an insect bite, but the most common types of lumps and bumps that are seen in rats are cysts and abscesses. These are particularly common in hairless rats. Sebaceous cysts are formed when a hair follicle becomes blocked with dirt, skin cells or excess oil and sebum, pus and fluid accumulates beneath the skin. Abscesses are pockets of infection under the skin that can be caused by wounds, scratches or sebaceous cysts. Cysts and abscesses can grow very large very quickly. They are located in the skin, whereas neoplastic tumours (cancer) is most frequently located under the skin. Tumours are more often hard whereas cysts and abscesses are softer. Treatment involves lancing and draining the cysts or abscess with antibiotic medication. You should have your rat examined by a vet to confirm that the lump is a cyst or abscess. Treatment is best performed by a vet and antibiotics are only available by prescription from a veterinary surgery.