The urinary tract is the one system that all owners pay very close attention to when they're trying to housetrain their puppy. The two bean-shaped kidneys are responsible for the excretory system. They are located — one on each side — in front of your dog's rear legs close to the spinal column. They have an important job — filtering waste from the blood and processing extra water and waste products. Sometimes the kidneys don't function properly and kidney failure results. There are two kinds of kidney failure — acute and chronic.