leg pain

Question
Hi my name is Pat and I have a 4 year old male Rotweiler named Jordan.  For about a week, Jordan has been having severe pain in his back left leg.  He hollers out when he tries to walk on it.  My husband took Jordan to the vet and they said he had arthritis and prescribed some Rimadyl 2x a day.  He has been on the medication since last Friday and is not getting any better and they took a x-ray of his  back left leg and hip and found nothing.  Yesterday, we took Jordan back to the vet and they checked his paw (nothing found) and wanted to charge us another $200 + to put him back to sleep and get a back x-ray.  They drew blood to see if he had any dieases since they found alot of fleas on him and they treated him for fleas as well.  The blood work will be back in a couple of days.  

The vet finally admitted that she didn't think he had arthritis as stated by another vet and was unsure of what it was.  Jordan has not had any problems with his leg before, no limping, stiffness, etc.  He is in alot of pain and we are unsure what to do.  The vet wanted to do the x-ray of his back, but stated they "don't perform that surgery in their office".  

Is there anything that you know of that would cause these symptoms and even if Jordan has a diease from fleas, would it cause this type of pain.  What should we do.  My husband is considering putting him to sleep because of the possible amount of money that it will cost to diagnosis him.  

Please help,

Thanks,
Pat

Answer
Well,it could be something as simple as a pulled muscle or bruised muscle/bone,or could be something as serious as bone cancer,but since you said the x-rays didn't show anything,he probably just sprained or pulled a muscle

Also,something you MAY want to look into is pet insurance,as it would save you the heartbreak of putting your beloved pet down if you can't afford treatmeant

I don't know of anything that fleas could carry that would cause him pain like that