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The breeding soundness examination should begin with a thorough reproductive and medical history, including information on previous cycles (onset and regularity), breeding management (past and intended), outcome of any breeding, and relevant family history, as well as routine medical information (diet, medications, environment, health status). A thorough physical examination, with particular attention given to the genitalia and mammary glands, should be performed.
. Screening for hereditary defects common to the breed should be advised, which may require techniques such as radiography, ophthalmoscopy, or specific DNA testing. Digital vaginal examination and vaginoscopy of the bitch may detect strictures or other defects of the vulva or vagina that may hinder copulation or whelping. Vaginal strictures are more commonly congenital than acquired and may be in the form of either a septate or a circumferential band. They most commonly form at the vestibulovaginal junction, caudal to the urethral papilla. The heritability of such defects is unknown. Strictures of the vagina or vestibule are not uncommon in the bitch and usually prevent normal copulation, but if pregnancy ensues from mating without a tie or from artificial insemination, dystocia can result. Septate bands can be easily resected surgically, but circumferential strictures are difficult to resolve without episiotomy and major revision and tend to reform.
. Evaluation of the mammary glands should include inspection of the nipples for normal anatomy. Routine vaginal cultures are not advised because the vagina normally harbors a wide variety of bacteria, including β-hemolytic streptococci and Mycoplasma spp . Bitches should be screened for brucellosis before each estrus when breeding is planned. A negative Brucellacanis screening test is reliable
Ejaculation occurs in 3 parts. The first part is a small amount of clean fluid that does not contain semen. The next part is the sperm-rich cloudy fluid. Typically, vigorous thrusting is associated with this part of the ejaculation and results in 0.5 to 3 mls of semen. The final phase of the ejaculation is the addition of clear prostatic fluid. If the ejaculate is to be used immediately, the prostatic fluid is allowed to mix with the remainder of the semen. If the semen is to be stored for any length of time, the collecting cone is removed as soon as the prostatic fluid begins to discharge. The presence of prostatic fluid in stored semen will result in diminished motility of the sperm and reduce fertility
Color: Healthy canine semen should be pearly white or translucent in color. Yellow semen indicates urine contamination, and urine is toxic to sperm. Red discoloration indicates that blood is present either from trauma, prostate problems or infection.
Sperm Motility: Since sperm have to be able to travel up the bitch's reproductive tract toward her eggs, the measure of how well sperm are moving and in what direction is important. A reading of 70% or greater motility is rated very good, 30% - 50% motility is fair, and 10% - 30 % demonstrates poor motility. Sperm should be moving rapidly forward, not in circles.
Concentration: The number of sperm in the ejacu- 250 million or more is desirable, especially if you are late determines its concentration. The more normal planning on freezing the semen. Dogs with lower consperm present, the better. Normal sperm counts can centrations can still get bitches pregnant, but higher vary from 1 million to over a billion per ejaculate, but counts increase the probability.
Morphology: Morphology is the evaluation of the structure of the individual sperm. Sperm have three parts: the head, which has a cap called an acrosome; the mid-piece, the location of the mitochondria or energy source; and, the tail. All three are important-the head for the genetic material, the mid-piece for energy to move and the tail to propel the sperm up the reproductive tract. Abnormal structure in any part may affect sperm movement or function. To be considered normal, a minimum of 80% of the sperm should have normal morphology.
Other cells or bacteria: The final consideration is to look for cells and bacteria in the semen sample. Normally there are few cells seen in an ejaculate; however, certain prostatic diseases may cause high numbers to be present. Excessive bacteria may indicate the possibility of infection, either in the testicles or the prostate.
Results • With natural breeding (assumes 3 breedings in a heat cycle) there is an 80 to 95 percent success rate of pregnancy. • With AI using fresh semen, 62 to 100 percent success rate • With AI using chilled semen, 59 to 80 percent success rate • With AI using frozen semen deposited into the vagina, 52 to 60 percent success rate • With AI using frozen semen deposited into the uterus, 0 to 80 percent success rate
The amount of semen that is required to give the best chance of a successful insemination varies depending on the size of the female. • For bitches less than 10 pounds (5 kg) 1.5 to 3 mls of semen are required per insemination. • For bitches 10 to 50 pounds (5 to 25 kg), 3 to 5 mls of semen is necessary. • For bitches over 50 pounds (25 kg), 5 to 8 mls of semen is necessary.
a. Transcervical Insemination (TCI) This is a non-surgical, non-invasive insemination technique whereby a catheter is passed through the cervix into the uterus using a specialised rigid endoscope. The semen is then flushed through the cervix and deposited directly into the uterus. This procedure can be visualised by both the veterinarian performing the procedure and the owner of the bitch because the endoscope has a camera fitted onto it which projects an image onto a television mounted on the wall (see Fig 3). This internationally recognised technique was developed by Dr Marion Wilson right here in New Zealand. It has been used for breeding dogs very successfully for over 15 years. It has the advantages of being anaesthetic and sedation free, non-surgical and relatively stress free in most bitches. It also has the distinct advantage in comparison to surgical AI in that more than one insemination can be carried out during the bitch’s heat.
b. Surgical Intra-uterine Insemination This technique involves a general anaesthetic and surgery. A small incision is made into the abdomen and the uterus identified and exteriorized. The semen is then injected directly into the uterine horns. This technique has the advantage of not requiring any specialized equipment but due to the invasive nature of this technique it can only be carried out once during the bitch’s heat which makes timing of insemination very important.
The body of the uterus is isolated and the horns are inspected.
The semen sample is gently infused toward each uterine horn.
The incision in the uterus is sutured closed. Usually only one suture is required.
The skin is closed with subcutaneous sutures. Sometimes there is almost no bleeding at all.
In traditional breeding programs, with natural service, the bitch is bred at least three times on the 9th, 11th and 13th day after the vulva begins to swell and blood tinged discharge is seen. On average, bitches tend to ovulate on the 12th day after the onset of vulvar swelling. The goal of breeding is to inseminate the bitch four days before ovulation and then every two days until the final insemination at two days after ovulation. Insemination two days after ovulation results in the maximum litter size.
There are many different types of catheters that can be used for vaginal AI. At this point a bulb at the end of the catheter is inflated to mimic the swelling of the dog’s bulbus glandis during mating. This not only prevents back flow of semen but stretches the vaginal wall resulting in oxytocin release and stimulation of vaginal and uterine smooth muscle contractions which facilitates transport of the sperm into the uterus. After the bulb is inflated, fresh semen is slowly injected down the catheter into the far end of the vagina. This is then followed by warm canine semen extender which functions to help flush the semen into the uterus in the same way prostatic fluid does during natural mating. This is a technique that can be used in all bitches, is non-invasive, requires less skill and equipment than the intra-uterine AI techniques and therefore is also economical. It is often used in maiden bitches and studs that fail to “tie” or mate, which can be due to a number of reasons.
