My dog’s back (spine) bones are sticking out a little and sometimes he wobbles when he walks. I noticed he's also a little hesitant to go up and down stairs. Besides these things, he's eating and drinking fine and still plays a lot. Should I be worried?
In short, yes, you should be concerned enough to have him evaluated. It is not an emergency (unless he is not able to walk suddenly), but he should be seen either by a surgeon or a neurologist. It sounds like he has neurologic deficits from a spinal cord injury. Frenchies are predisposed to developmental spinal disease that consists of malformed (misshapened) vertebrae leading to an abnormal posture and instability of the spinal column. This causes abnormal pressures on the spinal cord leading to dysfunction of the nerves leading to the limbs. It will manifest as knuckling when they walk, being wobbly, and reluctance to jump and climb stairs. It is not necessarily painful, but should be addressed as it can progress in severity. Treatment is typically a combination of medications and surgery. Outcomes are generally good. There are other possible causes as well including intervertebral disc disease; infectious or inflammatory disease; and a slew of others. Hopefully this is helpful and good luck.