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 The dog may lick excessively at it's genital region. 2  The dog and/or it's bedding smell strongly of urine.  With incontinence the dog does not know that it is passing the urine, and urine leaks when it is relaxed or occasionally urine can leak during normal activity. If a dog does know what is happening, it will deliberately urinate in unfamiliar places - but urine will not necessarily leak where the dog lies down.