Much of the male Patterdale Terrier's reproductive anatomy is visible on the outside of the body, whereas the female's are largely hidden. He should have two testicles carried down in the scrotal sac.
Retained testicles (testicles that haven’t ‘dropped’) are not normal, and are caused by a genetic defect and can cause many problems inside the body. Medical advice should be sought to treat the issue.
If a male Patterdale has been born with just one testicle and although still able to reproduce, it is advised that he is neutered as soon as he is old enough to handle the surgery - this is typically advised around the one year mark.
To breed from him might not be the best idea as the genetic fault may be passed down to his offspring and that would not be in the best interest of the Patterdale Terrier breed.
A healthy Patterdale Terrier male will have 250 million to more than a billion sperm in one ejaculate of spermatic fluid. Not all the sperm are healthy. Some may have deformed heads or tails, or missing tails and other deformities.
Some sperm swim in circles instead of going forwards. However, only one healthy sperm, swimming up the vagina, propelled by its rapidly moving tail to the fallopian tube and penetrating the bitch's egg, will result in a puppy.
The extra sperm, if not required by an egg, will die in about 4 days.
The penis, much like the human male, is used for passing urine and for transmission of semen.
It differs from the human penis in that the Patterdale Terrier's penis actually has a small bone in it, as well as a bulb (bulbous glandis) near the base on either side, which swells five times its size with blood when the penis is erect.
Once the Patterdale has his penis inside the bitch (coitus) he begins 'thrusting' to stimulate ejaculation.
Upon ejaculation the female's vaginal muscle traps the male's bulbous glandis in what is called 'the tie'. The 'tie'' cannot be broken until all the semen is pumped from both testicles, which happens as alternative spurts from each testis.
The 'tie' only assures that the seminal fluid - the ejaculate - will not leak back out and the slower sperm have a chance to swim up to the fallopian tubes.
Once the tie has occurred, you MUST WAIT until the female relaxes her vaginal 'locking' muscle and breaks the tie to release the male. Simply keep her calm and stroke the bitch until she relaxes - nature will take its course.
Normally, the sheath which covers the penis will slide back over the penis once the swelling has subsided. However you may need to gently pull the sheath back over the penis to ensure the male suffers no pain.