Q: My two-year-old male hamster has developed two large black spots on his rump which look like cancerous growths.
He has been losing hair and generally seems a bit under the weather. What could be the cause?
A: I am assuming your hamster is a golden (Syrian). These live on average for two-and-a-half years with some living up to three. The spots you describe are very likely to be the scent glands that both male and female hamsters possess.Hamsters use these glands to rub against objects in order to mark out their territory.They are located on the flanks near the hips and when they are pigmented, as with your hamster, are often confused with the skin cancer melanoma.Occasionally the scent glands can become cancerous but this would normally only affect one gland. The fact that you can see the scent glands is due to the hair loss.This, along with being a bit under the weather, is significant and I would advise a check-up with your vet.Losing hair at his age is often a sign of a parasitic mite infestation called demodicosis.The mite is present in all hamsters but it only causes problems if their immune system is compromised. This may be due to some underlying disease or simply a reflection of old age when the immune system becomes weakened.Treatment of any underlying disease and associated demodicosis may prolong his life.David Grant MBE was a vet at the RSPCA Harmsworth Hospital for Animals. Write to him at Express Yourself, 10 Lower Thames Street, London EC3R 6EN. He is unable to enter into individual correspondence.