Semen Collection and Evaluation

Ideally, several days of sexual rest should be allowed prior to semen collection and evaluation.

Canine semen is most easily collected using masturbation with a gloved or bare hand, although some operators find the process distasteful and prefer to use an artificial vagina (AV). If a reusable AV is used, it should be cleaned by washing and chemical disinfection then rinsed several times with distilled water and air dried. The artificial vagina and attached plastic tube are warmed to body temperature and lubricated with a small amount of sterile aqueous lubricant.

It is much easier to obtain an ejaculate when an estrous bitch is present; therefore owners should be asked to bring in teasers when appointment are made. Alternatively, a non estrous bitch of the same breed or size may be used. A commercially available pheromone (methyl paraben) may be used to stimulate the male but we have limited experience in its use. It is sometimes very difficult to collect semen if no bitch is available at all can it can be done.

Optimally, the male and female are brought together on leashes in a quiet room with nonskid flooring. As the dog sniffs at the bitch's vulva or mounts her, the collector quickly moves the prepuce back, behind the bulbous glandis and directs the tip of the penis into the AV, held in the left hand. Once the artificial vagina is slipped onto the penis, the right hand is used to hold the artificial vagina onto the penis while exerting firm pressure around the back of the bulbous glandis. Once this occurs, the dog will usually show pelvic thrusting and normal ejaculation. An AV is certainly not essential to collect semen from dogs. Excellent ejaculates can be obtained by hand collection alone.

If a gloved or bare hand is used instead of an AV, the dog is masturbated rapidly for a few seconds until he gains a full erection. In the process, the prepuce is slipped behind the bulbous glandis. Masturbation ceases and the hand held behind the bulbous glandis using very firm pressure, until ejaculation is complete. The other hand is used to hold a plastic bag over the end of the penis.

Almost any warm receptacle can be used to collect the semen but most commonly sterile "Whirlpak" bags are used. Syringe casings and other hard objects should be avoided as the penis is very easily traumatized during collection and substantial bleeding may occur into the ejaculate. This does not seem to decrease fertility in dogs but it interferes with semen evaluation and of course, alarm owners.

Semen can be collected when the bulbous glandis expands within the prepuce but some dogs object to this. Therefore, it is usually best to be sure that the bulbous glandis is out of the prepuce before it expands.

The reader can see therefore than the term "masturbation" is somewhat misleading. Most of the contact time consists of pressure exertion behind the bulbous glandis; a process identical to that used with an artificial vagina!

Ejaculation occurs intermittently over a variable period, perhaps five to 15 minutes, usually just long enough to deprive the collector (squatting on the floor) of all blood flow and feeling to the legs.

If pressure is maintained firmly around the bulbous glandis, pulsations can be palpated in the urethra. The anus will also be observed to contract in a rhythmic fashion. The dog may stop ejaculating for several minutes then pulsations will resume.

Initially, a few drops (one to 3 ml) of clear to slightly cloudy pre-sperm fraction are ejaculated, followed by a whitish sperm-rich fraction (0.1 to 6.0 ml) but most often these fractions are mixed and only a homogeneous light gray/opalescent ejaculate is obtained. The collector should try keep one hand around the collection vessel to keep it near body temperature. This is easiest when a plastic bag is used as a collection vessel.

Soon after the dog begins to ejaculate, he will often lift his hind limb as though attempting to step into the rump-to-rump position that occurs during natural breeding. If this is observed, the collector should allow the dog to step over his/her arm so that the penis then extends out caudally from the dog. Soon the clear, third fraction of the ejaculate (mostly prostatic fluid) is ejaculated increasing the volume to as much as 60 ml. If the semen is being collected for artificial insemination as well as evaluation, enough prostatic fraction is collected to bring the total volume to three to 10 ml so large numbers of sperm are not lost in the insemination process and the insemination volume is comfortable to work with. Frequently, only a few ml of semen are collected but total sperm numbers, not semen volume, is what is important in A.I.

After collection is complete, the male is observed until his erection subsides. Paraphimosis may occur following collection, so the dog must never be kenneled or sent home until the penis is completely inside the prepuce. To prevent paraphimosis, one should lubricate the preputial opening liberally after semen collection.