See a vet. Excessive yawning can be from lack of oxygen, either due to something with the lungs, heart or lack of red blood cells. Hypoxia can also cause motor skill problems. You need to get him to a vet quickly if you don't want to lose him.
Caring for your dog's health and well-being aren't always that easy. While our members may have good advice, it is just advice. Please use this section as a resource to discuss "diagnosed" conditions and treatment options for your dog.
*Important - All serious concerns with your dog's health and well-being should be handled by a Veterinarian, so please refrain from asking questions that are best suited for their office.