My guinea pig has a breast growth and is losing hair. What should I do?

Hello! Masses near the breast area of a guinea pig could be a few different things. My first thought is a mammary tumor, which is common in rodent species, especially as they get older. Mammary tumors in rodents are usually benign, but rarely they are malignant and could spread to other parts of the body, so most vets generally recommend surgical removal of these masses if the guinea pig is healthy enough for surgery. The mass could also be a fluid-filled cyst or an abscess. All of these diagnoses will require the help of a veterinarian to confirm. At the vet, they will give Lola a complete physical exam, and they will most likely collect a small sample of cells from the mass to look at under the microscope with a small needle. This is called a fine needle aspirate, or FNA. The type of tissue or liquid that comes out, as well as what those cells look like under the microscope, will determine the recommended course of action. If it's a tumor, they may suggest removal. If it's a cyst, they may just drain it and ask you to watch for recurrence. If it is an abscess, it will also likely be drained, and Lola will probably be put on antibiotics.

I strongly suggest that you make an appointment with Lola's regular vet, or, if you don't yet have one, with an exotics specialist. Here is one that is nearby:
Northwest Exotic Veterinary Clinic
572 S Bartlett Rd, Streamwood, IL 60107
(630) 540-2490

Good luck, and I hope Lola recovers well!