I am taking Jake to the vet this afternoon. He has as you all know had issues with his back leg...he would limp every so often and would whine in pain...the vet didn't see anything wrong with his leg and gave us pain killers to give him when he needed them. Well fast forward...for about 2 weeks, he has been acting weird...we thought it was because LuLu belle was in heat and that had somehow made him agitated a bit. The last 2 nights he has been crying out when he tries to move at night. It isn't when he is just walking or lying but when he goes to lay down or get up. It isn't the usual back leg hurting and I can't tell where the pain is coming from. To make this long email to the point, I am so worried about bone cancer. Jake is now 4...he is awfully large, tall and 145 pounds. He is panting heavily and I laid with him around midnight to calm him. What should I ask the vet? And what tests should be run?