The border traverses a variety of terrains, ranging from major urban areas to uninhabitable deserts. Approximately 350 million legal crossings occur annually, and is the most frequently crossed border in the world. The total length of the continental border is 1,954 miles (3,145 km).
Only a veterinarian will know what's wrong with your dog but usually stumbling, wobbling and falling down is associated with neurological problems, especially if there aren't any other signs. I would really take him to the vet as soon as you can.
Check for dehydration. Diarrhea is basically feces that contain a large amount of fluid. If the dog passes a lot of diarrhea and doesn't replace that fluid, he will become dehydrated. Dehydration reduces the blood supply to organs such as the liver or kidneys, which can potentially cause damage.1  To test for dehydration, lift the dog's scruff away from the shoulder blades and then let it go.. Put the dog on a 12 to 24-hour fast. The presence of food in the gut causes contractions of the bowel wall to push food along. But if the dog has diarrhea, these contractions can be over-enthusiastic and push food through too quickly in the form of diarrhea.