Our labrador has had a tumor on his side for at least a year. It is just under the skin and seems to be attached to his hide but not to his ribcage. The vet said to just keep an eye on it. It had been the size of a small marble but recently he had his 3 year rabies booster and it has grown a bit larger. I gave him a dose of lachesis after the booster, and now I don't know if it was the shot or the remedy that has caused the changes. I remember my dog as a child had bumps on his rump for years that caused no health problems, and now I don't know what to do. The vet has offered the option of having it removed for about $500, which is do-able for us, but it involves boarding him and therefore giving him additional vaccines. I don't want to compromise his immune system further by subjecting him to that. The rabies booster was a legal requirement. He is otherwise in excellent health, eats well and is very active. I would appreciate any suggestions for the proper course of action.