In actively breeding males, it is recommended that semen be comprehensively evaluated every 2 – 4 months at a minimum. In this way, any change in the status of the ejaculate will be detected early. In males that are not being used actively, it is recommended that semen be evaluated just prior to the onset of the bitch’s season during which breeding will occur or at the very start of the bitch’s cycle. In this way one can feel relatively confident that semen quality will be adequate for the upcoming breeding. If chilled semen is to be used for the first time, a longevity exam is recommended to ensure the semen will ship adequately.
A small number of males may benefit from a clean-out collection in the week prior to anticipated breeding but most males clean out old sperm on a daily basis, so this isn’t necessary. If the male has a history of the first collection being poor and subsequent collections having improved motility or morphology, a clean-out collection should be performed. Any deterioration in semen quality or a change in fertility (decreased litter size or pregnancy rates) should instigate further investigation as to the cause of the change.
Males should not be collected or bred more often than every other day on a regular basis. If the dog has more than one bitch to breed in a week, then ovulation timing should be performed to ensure the breedings are performed at the optimal time for each bitch. If it is optimal to breed both bitches on the same day and sperm numbers and semen quality allows, the ejaculates can be split and a minimum breeding dose sent or inseminated into to each bitch to be bred. Utilizing advanced reproductive techniques such as transcervical or surgical insemination can reduce the breeding dose required for each bitch and will maximize use of the dog.
If absolutely necessary, a male can be collected daily for 3 – 5 days in a row (depending on the male’s daily sperm output) without completely depleting sperm stores. It is better not to do more than one natural breeding daily unless it has been determined that there are adequate sperm numbers to do this. In most cases, collecting a dog twice in one day results in about ½ the number of sperm in the second collection than was in the first collection. So, a dog with average sperm number would provide an adequate dose to the first bitch bred, but not to the second. As a general rule of thumb, males with increased scrotal width and normal semen characteristics will have more sperm reserves than those with smaller total scrotal width. This means that toy and small breed dogs will deplete their sperm numbers with fewer daily collections (3 days in a row) than will males of the larger breeds (5 days in a row). If the male is not allowed a day of rest between regular collections, sperm numbers may decrease enough to affect pregnancy rates and litter size.
Collection and storage of frozen semen can alleviate the stress of overuse in popular males. Semen evaluation and post thaw testing, should be performed every time the semen is frozen; and results of both pre- and post-thaw testing should be provided to the bitch owner, along with any fertility information available from previous breedings. Number of breeding doses per ejaculate varies with the male (sperm numbers and semen quality) and may range from <1 – 10+ doses/ejaculate. Again, males with greater total scrotal width tend to have more breeding doses/ejaculate, assuming semen quality is good. Males with any type of prostatic disease are poor candidates for semen freezing and should have their prostatic disease treated prior to freezing. Any male that seems to have good quality semen pre-freeze that has poor quality semen post-thaw, should be evaluated for prostate disease and if none is found, then a different extender should be used on the next attempt.
Owners should ensure that their freezing facility is providing an adequate breeding dose when preparing frozen semen. For toy, small and medium breeds, a minimum of 100- 125 million normal, motile sperm is ideal; while for large and giant breeds, a minimum of 150 – 200 million normal, motile sperm is recommended. With the investment involved for the bitch owner in a frozen breeding, ensuring that adequate sperm numbers of normal motile sperm are available will maximize chances of normal pregnancy rates and litter size. The dog owner can request a minimum breeding dose be prepared and provide the number of normal, motile sperm desired in each dose to the freezing facility prior to the actual freeze.
Brucellosis testing is recommended prior to each breeding if dogs are used infrequently, regardless of the type of breeding being performed. Brucellosis can be transmitted either by mucosal contact (aerosol or oral/nasal contact with infected urine or vaginal secrections) or venereally. So, a male that has never been bred before can still be positive. Males that are being bred frequently (more than once every 2 months) should be tested every 2-3 months. All males should have their prostate examined per rectum (and by ultrasound if abnormal) and have a comprehensive physical examination including complete blood count, serum chemistry and thyroid screening (for autoantibodies) yearly. Other vaccinations should be determined following discussion with your regular veterinarian. Dogs should be dewormed at least annually and specific deworming programs should be tailored to the individual dog’s needs and the kennel situation.
Courtesy of Dr Cheryl Lopate of REPRODUCTIVE REVOLUTIONS