While this may seem like an obvious question, in some cases the answer to "Is it a boy or a girl?" may not be so easy when it comes to some puppies. Within the canine species, as with almost any other type of animal, there are sometimes genetic mix-ups that result in congenital problems in sexual differentiation.
This condition, known as hermaphrodism, occurs when an animal is born with both male and female sexual organs. They may not be functional in the sense that the organs may not allow the dog to reproduce, but they can be present. Often hermaphrodism results in sterility in the dog and typically vets recommend both spaying and neutering to prevent any further complications that can occur in the rare case that the dog may conceive. Since hermaphrodism is a genetic mistake, there is a good chance that the puppy will also have other congenital conditions that may develop later.
There are some breeds of dogs that have hermaphrodism within the breeding lines. American Cocker Spaniels, German Short haired Pointers, English Cocker Spaniels and Curly-coated Retrievers have an inherited type of hermaphrodism that makes this condition more common within the breed or in mixed breeds with these crosses. It is important to note that the condition itself is relatively rare within any dog breed but it is more typically seen in the above mentioned breeds.
In hermaphrodism the dog may have some or all of the genitals of both sexes. They will often have a penis as well as a vulva, although they may or may not have the full reproductive system of both a male and female. Male dogs will often have nipples the same as a female, this is perfectly normal and is not a sign of hermaphrodism.
In some dogs the sexual organs are mismatched, or incorrect for the external sexual organs. It may be possible for a dog to have penis and an ovary instead of a testicle or one of each ovary and testicle. In these cases the sexual reproduction organs are called an ovotestis. These animals will be sterile and should be neutered or spayed at the earliest possible point to avoid any possible problems with the development of the genital or reproductive system.
Most puppies that are born with hermaphrodism can lead perfectly normal lives after being spayed and/or neutered. Since the physical aspects of most male and female dogs are not varied and these animals cannot be used in the show ring for conformation the issue quickly becomes unimportant once corrected. Hermaphrodite dogs can be wonderful companions and are not aggressive or timid, although there are many myths and misconceptions about their temperament. Since a hermaphrodite dog may have other genetic conditions further DNA and health testing may be recommended by your veterinarian.