The dog's urinary system's purpose is to process and get rid of liquid wastes. The main attractions in this system are the kidneys, the bladder and the urethra. Ailments in the urinary tract are more common in older dogs but can really occur at any time in any dog. The male dog's reproductive system matures around eight months of age. He can reproduce any time of the year.
Female dogs can mate and reproduce twice a year.
Pregnancy of a dog is about 60 days and she will have what is called a litter of puppies. The female reaches sexual maturity about the same time as the male dog but breeding is usually not recommend for the female until she reaches full maturity growth wise. There are many other aspects to a dog's anatomy that are clearly more comprehensive and detailed than what is described here. Knowing the dogs general anatomy is very helpful and will be of great use should the time come that you need it. Learn man's best friend's anatomy by reading this article.