11 year old pekingese has lump in armpit?

My pekingese has a lump in his armpit,its round and is about the size of half a ping pong ball its hard and isn't hurting him he eats,sleeps and is very active and it doesn't seem to be bothering him.Any information would be greatly appreciated

Could be a tumour.So in that case get him to the vet immediately, so they can access the lump and determine what exactly it is. If you don't get your dog to the vet and it is cancerous, then he will deteriorate very quickly.If it is a tumour, i pray for you that it is benign.Good Luck.

Any lump should be checked by a vet. It could be something simple like a fatty cyst, but it could also be more serious, so the sooner you find out, the better. Vet.

If it's in the armpit, it sounds like a swollen lymph node. Are there any other swollen places elsewhere? Swollen lymph nodes usually won't hurt or cause the dog any immediate pain itself, however you need to get your dog to the vet. Swollen lymph nodes usually mean an infection, inflammatory condition or possibly even cancer, such as lymphoma etc. In the early stages of lymphoma a dog may not even show any signs of sickness. Get him checked out and bloodwork done. Your vet can aspirate the lymph node and investigate further, to see if it is some type of cancer. Good luck and hope your little guy will be ok.

Most lumps in an older dog are due to Lipomas (fatty tumors) however they are normally soft and moveable. Any hard lump should be considered possible cancer until checked out by needle aspiration at the vets.