Help...Diet Changes

My 8 year old dog (cocker spaniel dachshund mix) recently under went knee surgery, he is nearly recuperated. It has been a long 3 months, and Sparky has been ever patient and seems understanding. The first few weeks there were no walks, and he was confined to one room. The next recovery stage allowed him short walks, but still no stairs, so the confinement continued. Now we are in the home stretch. He is able to go for longer walks, use the stairs, and soon he will be able to go to his favorite off leash area and play with his canine friends. Yippee!

However the past week he's got me and his dad worried, as his hearty appetite for his nightly meal has disappeared? Before all these changes in Sparky's routine, he chowed down his dinner in mere seconds. Now the food remains in his dish for hours after dinner time? When meal time rolls around he still acts like his crazy I'm starving feed me self, but when the dish is given to him he eats a bite or two then walks away? His stool deposits in the yard are softer then normal but not alarmingly different? He has plently of energy for his daily walk? There is no tenderness in his belly area? So we are at a loss? Not sure if we should take him to the doctor or what? So I was wondering if any one else's canine friends have had a similar experience??
:confused:

He may have a tummy ache! I would consult the vet, he/she may advise you to give him a Pepto Bismol tablet...that's what ours recommends for diarreaha and upset stomach. Good luck and let us know the outcome.