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.
1. Pay attention to your dog's behavior. A dehydrated dog with the energy to do so will typically seek water to drink. If your dog is dehydrated, you may notice unusual behavior, such as restlessness or pacing, as if looking for water.1  Your dog may repeatedly lick its lips and/or have an anxious facial expression if it is unable to find enough water.. Check the dog's scruff. The classic dehydration test that you've probably seen the vet do at the animal clinic is lifting the dog's scruff. What this test actually measures is the skin's elastic recoil, which decreases with dehydration.