My year old Basset Hound puppy, Tanner, has been acting strange for about the past week. He seems very lethargic and barely has an appetite. He's lost some weight, and whenever he walks he tends to favor his back hips. He had surgery in January on his front left leg to fix an ununited ancheol process. He will eat people food, like noodles, but has almost no interest in dog food. Bowel movements are normal as far as I can tell. Any help would be greatly appreciated. Thanks!!!