Canine Reproduction, Part II
In Canine Reproduction, Part I, I discussed the female dog’s reproductive system. Now it’s time to select the ultimate bird dog sire. The first questions to ask the prospective dog’s owner should verify the sire is clear of genetic disorders (mandibular prognathism, exercise induced collapse, progressive retinal degeneration, hip dysplasia, etc) and Brucella canis free. Finally, inquire to see if the dog has been through a complete breeding soundness examination (BSE). (The AKC requires that all sires less than 7 months and more than 12 years of age have a breeding soundness evaluation (BSE) preformed by a veterinarian before they will register a litter.)
A thorough breeding soundness evaluation (BSE) performed by your veterinarian should include assessment of the dog’s overall conditioning and health. The dog should be in top physical condition and have a lean body mass (he should have an ideal body conditioning score (BSC) of 4.5 to 5 on a scale of 1 to 9). He should have good oral health and be sound without severe osteoarthritis. His prepuce, penis, and testicles should be free of anatomical defects and the prepuce should be cultured to determine what potential pathogens might be present — there are several bacterial species that are normal flora of the prepuce and urethra of the penis. A rectal exam is very important on the dog to assess his prostate size and shape to insure that the dog does not have benign prostatic hypertrophy (BPH) or perianal gland adenomas that commonly occur in middle-aged intact dogs. Finally, he should have blood collected to rule out Brucellosis, hypothyroidism and any other hematological abnormalities.
Semen collection and assessment are very important components of the BSE. Manual ejaculation of the stud dog is best performed with a teaser bitch (hopefully in estrus) present to increase libido and improve semen quality. There are some commercially available pheromones that can be used to tease the dog if the bitch is not in estrus. I typically collect the dog with a sterile vinyl sleeve. Two familiar handlers should be present while collecting the semen. I’ve had to muzzle my pointer bitch when used as a teaser to prevent her from biting the stud dog. The ejaculate has three fractions to it, with the second fraction containing the sperm. The sperm-rich fraction typically occurs while the dog is vigorously thrusting.
The semen is evaluated on volume, color, and pH of the prostatic fluid, percentage of progressive sperm motility, concentration and total number of sperm present in the ejaculate. The seminal fluids should also be cultured for bacteria and there should be a cytological evaluation preformed as well to check for the presences of white blood cells, red blood cells, and any other abnormal cells.
AI Collection Kit
Canine semen quality may vary for a number of reasons such as: the environment it was collected in, decreased libido, stress of over conditioning, how frequently the dog has been collected, systemic or reproductive disease, age and breed of the dog and the time of season the dog is collected. Semen quality is optimum in dogs that are collected no more frequently than every 3 to 5 days. Normal canine ejaculates contain greater than 80 percent normal morphology of the sperm and has progressive motility at about 70 to 80 percent or greater. The total concentration of sperm in a single ejaculate can range from 300 million to 2 billion sperm.
One of the wonderful characteristics of canine semen is that it is resistant to cold shock and can be refrigerated and used several days later or frozen in liquid nitrogen for future use — sometimes several years after the sire has gone on to the coverts beyond the rainbow bridge. Some dogs may have tremendous semen quality during their BSE, but their sperm does not do well after being chilled or frozen. I would therefore suggest that a comprehensive BSE is not complete without evaluation on sires that you plan to ship semen with or plan for the distant future propagation of his progeny. This can be accomplished by collecting the dog and extending (extenders are products added to the semen to buffer the pH, give energy to the sperm, kill bacteria, and protect the sperm as they cool — there are several commercial products available) his semen and placing it in the fridge for 24 hours and then thawing it out. The semen should be reevaluated for progressive motility and morphology as stated before. Optimum conception rates are obtained with chilled semen if the bitch is inseminated within a 48 hours window from the time of collection. Semen can be shipped in the same canisters that are available and popular in the equine world; there are also canine-specific commercially available canisters.
On a final note, the over all physical condition of the sire is crucial to a successful breeding program. A judicious exercise and conditioning program along with excellent nutrition can make all the difference in the quality of your program. Additionally, it can not be stressed enough how very important it is to make sure both your sire and the bitches that he is scheduled to breed (natural as well as artificial) are negative for brucellosis. Brucellosis is a bacterial infection that leads to late term (45-60 days) abortion in the bitch and severe testicular problems in the sire. The bacteria are very hard to get rid of even in the presence of antibiotics and can persist in the prostate and affect the semen quality for many years. Bitches should have a negative test 7 days prior to breeding.
Part I of Canine Reproduction can be found in Categories, listed under “Shawn K. Wayment, DVM”