Semen collection in the dog.

This review will discuss semen collection in the dog. Semen samples may be collected from male dogs for the purposes of artificial insemination, cryopreservation or diagnosis. The materials needed for semen collection depend on which method is used and the collector's level of expertise with this procedure. At minimum, two sterile centrifuge tubes or specimen cups can be used to collect semen as it is ejaculated (for the combined first and second fractions and for the third fraction). The most common method for semen collection in the dog is by digital stimulation. Under ideal conditions, this procedure is performed in the presence of an estrous bitch. Initially, the dog's penis is vigorously massaged through the prepuce at the level of the bulbus glandis (caudal-most aspect of the prepuce) until a partial erection develops (initial engorgement of the bulbus glandis). The prepuce is quickly retracted past the bulbus glandis and firm constant pressure is applied to the penis behind the bulbus glandis by squeezing the penis between index finger and thumb. Pelvic thrusting may occur following application of pressure behind the bulbus glandis during the development a "full" erection. The ejaculate is composed of three fractions: first (sperm-poor), second (sperm-rich) and third (prostatic fluid). In addition to digital stimulation of the penis, spermatozoa have been collected from dogs using electroejaculation and pharmacologic methods.