PREPARATIONS
The first step in preparing for breeding is to draw up a contract. A contract and breeding agreement should state the names of the couple to be bred, as well as those of their respective sire and dam. It should also include the names of the owners of both bitch and dog, their addresses and phone numbers, the names of the handler and of the witness to the breeding, the dates of the breeding, the stud fee and payment date, or whether a choice of litter puppy is to be taken in lieu of the fee. A complete list of charges should include handling the breeding, the board of the bitch, any charge for trips to the airport for shipping and returning, any vet's fees involved, the number of puppies that constitutes a live litter, whether there will be a return service if the bitch does not whelp or if none of the puppies survive the whelping. The contract should be drawn up in duplicate and signed by both parties.
Next, a vet must give the bitch a complete physical examination and medical evaluation. About two to three months (and no later than one month) before she is due in season, steps should be taken to prepare the bitch for breeding. Checks should be made for both internal and external parasites and if found, should be eliminated.
One month before her cycle, the vet should give the bitch boosters to her immunizations as this will help to protect the whelps from disease. The bitch must also have a test for brucellosis (an almost incurable, infectious disease spread by sexual secretions that causes spontaneous abortions) and be cleared for any specific breed health problems (hip dysplasia, eye defects etc.). These tests should include screening for genetic disease in the systems including orthopedics, eyes, cardiovascular (for heart and lung disease), neurological, skin and temperament. The maiden bitch should be examined for vaginal strictures that might restrict copulation. The stud dog must also have testing for communicable diseases, and have the quality and quantity of its sperm tested. Like the bitch, it must he tested for the genetic diseases.
Most bitches cycle or come into heat twice a year, often in the spring and fall. The Basenji is an exception coming into heat only once a year in the fall. The Toys and smaller breeds
have their first cycle at about eight months of age, while the larger breeds usually start later - even up to fourteen or fifteen months. It is not advisable to breed a young bitch at her first season but better to wait until the second when she will be more physically mature. The lining of the uterus becomes a little thicker with each additional season making it slightly more difficult for the bitch to conceive. Breeding a bitch for the first time when she is healthy and best able to carry her young is preferable to waiting until she is four or five years old.
ANATOMY AND PHYSIOLOGY
The dog's major reproductive organs are external - the testes and the penis. These are connected by ducts inside the abdomen. The two testes are located in the scrotum, a divided pouch of skin that lies between the thighs. The testes are responsible for producing sperm and secreting testosterone, the hormone responsible for male sex characteristics. Nature has arranged them outside the body to keep the sperm cool - it does not tolerate body temperature for long. The penis is enclosed by a sheath of skin (known as the sheath or prepuce), and is composed of soft erectile tissue and a small central bone. At the base of the penis is an area called the bulbous glandis. This quickly swells into a large, hard mound when the penis engorges and becomes rigid. This, together with a constrictive, muscular ridge at the opening of the bitch's vulva, is responsible for the interlocking of the two animals during copulation - known as a "tie."
Except for the mammary glands and the vulva, the bitch's major reproductive organs are internal. They are comprised of a pair of ovaries and fallopian tubes, plus the uterus, cervix and vagina. The two ovaries lie behind the kidneys at about the last rib. The ovaries produce the eggs (or ova) and also the hormones responsible for the female sex characteristics. Each ovary is enclosed by a tiny fallopian tube that connects the ovary to the upper end of a uterine tube. The uterus is bi-horned or Y-shaped above the short, main body, and it is in each "horn" that the embryo will develop. The mouth of the uterus or cervix is tightly closed except when the bitch is in heat or in the act of whelping. The cervix opens into the vagina which ends externally in the vulva. This is made up of erectile tissue which swells and softens during heat or estrus, thus facilitating the act of breeding.
THE FEMALE CYCLE
There are four stages in the bitch's reproductive cycle: proestrus, estrus, diestrus and anestrus. The cycle begins with the proestrus - a time when the vulva begins to swell and the start of a bloody discharge may be seen. This stage can last from as few as three days to as many as eighteen, with the average being about nine days. The bloody discharge comes from the congestion and discharge of the mucous membrane lining of the uterus, the endometrium. As this point the uterus is preparing to accept eggs. At the end of proestrus, the bitch goes into a standing stage that generally lasts about nine days but again may v-,try from three days to three weeks. It is during this period that the bitch will accept the dog and fertilization may take place.
Some bitches continue with a bloody discharge but the majority have a diminished discharge and the color lightens gradually from red to a straw color when the bitch is ready to breed. The vulva continues to swell and also becomes soft. It is now that the bitch will become flirtatious and will stand for the dog to mount - hence the term "standing heat." The bitch will usually flag at this time pulling her tail up and off to the side away from the vulva. She will do this as a response to the mounting action of the dog or even when touched or rubbed at the base of the tail. Ovulation is most likely to occur somewhere between the tenth and fourteenth day of the cycle, and this is when most successful breedings take place. However, these time scales are all averages and may not necessarily be the "normal" time frame for an individual bitch.
The diestrus stage in the cycle is approximately sixty days after the estrus, when the bitch will usually refuse a dog. The anestrus is the period of sexual inactivity which leads up to the proestrus.
All of this activity revolves around the secretion of the female hormones by the ovaries. The level of estrogen, which initiates the proestrus period, generally starts about one month before and gradually rises, peaks, and then falls just below proestrus. At that time, the progesterone (the hormones required for maintaining pregnancy) starts to rise, peaks and stays at a higher level until either labor or a false pregnancy develop. The level of luteinizing hormone (known as LH) suddenly surges when the estrogen level falls and the progesterone level rises, and it is this surge that stimulates the ovaries to release their eggs. Two to three days after the stimulation, the eggs are released and travel through the fallopian tubes to the uterus. They then take another two or three days to mature and become ready for possible fertilization by the millions of sperm that swim around and brush against each ovum after the coupling as taken place. Once a sperm has entered a mature egg and it has its full set of chromosomes, no other sperm can enter that egg. However, there are still plenty of other eggs left which might become fertilized by different sperm.
One or two breedings to the stud does not mean that all fertilization has indeed taken place, so the breeder must not allow the bitch into contact with other males until well into her diestrus when she will definitely reject all dogs. If in the interim she mates by accident with a second dog, none of the offspring will be eligible for registration because there is no way to identify the sire of each whelp. It is possible for a bitch to he fertilized by a umber of dogs during one season. The simplest way to find the right breeding date is to allow dogs to mate at their natural calling time. Another is to analyze slides prepared from the lining of the vagina.
Hormonal action precipitates changes in the appearance and condition of the epithelial cells in the vagina but, to be accurate to any degree, it is essential to have a series of slides that run from the latter part of the proestrus on into estrus. Some vets are able to determine the best breeding time through vaginal inspections. Also, simple blood tests (progesterone assays) determine when a bitch has ovulated by charting the sudden rise in the progesterone level (coinciding with the LH surge) or whether or not she is maintaining a high enough level to sustain pregnancy.