Q: I have a guinea pig that is about 4 years old. I was giving him a bath when I noticed a spot near his bottom that is dark pink and kind of rough on the skin. His hair is very hard and has an orange color to it. It’s like he’s had Vaseline or something stuck in his hair for days. What could be causing this? Do you think my guinea pig could have the mites? If so, what can I do for him?
A: What you are describing could be normal secretions from sebaceous glands on the skin of your guinea pig. I am assuming you have an intact (not neutered) male guinea pig. If so, they are prone as they get older to secrete more than the usual liquid from sebaceous glands in their skin. These secretions can become sticky and mat the hair. They can also give sort of a greasy appearance to the guinea pig.
Treatment to remove these secretions can be as simple as using medicated shampoos safe for guinea pigs. Do not use shampoos made for people. But there are also abnormal secretions, sometimes associated with diseased sebaceous glands, which can cause such an overproduction of this material. In such cases, the skin might change color and even look orange. These conditions need more aggressive treatment than a medicated shampoo.
During a physical examination, your veterinarian can usually tell based on the appearance of the skin and haircoat if the condition is just an overproduction of the normal secretions or if it is something more serious.