Natural Breeding of Dogs
Natural breeding is classified as physically breeding the bitch with the stud dog via introduction(s), bitch reception, and sire mounting. Timing of natural breeding is different from artificial insemination because with natural breeding, the sperm can live for several days. Therefore, timing does not need to be as exact.
Proestrus is considered the first day that any signs of the heat (estrus) are noted, such as vulvar swelling or vulvar discharge. Record this day on your calendar. Five days after the onset of proestrus (Day 6) introduce the bitch to the stud to see if she will stand for him (be receptive to him). For territorial reasons, always take the bitch to the stud. The stud will be more comfortable and confident and more likely to attempt mounting. The bitch will likely be more submissive in an unfamiliar environment. Present the bitch every other day to the male until she stands. Once she is receptive, allow the dogs to breed every 2-3 days until she will no longer allow the stud to mount her. Record all activity on your calendar. Bitches usually stop standing around Day 16-17. With a healthy, young bitch and fertile male, 86% success rates can be achieved with this technique.
If using progesterone test kits to maximize timing, start testing on Day 5 of proestrus. Test every other day until progesterone reaches 5 ng/ml. Breed the dogs 48-72 hours later. For most test kits, 5ng/ml is indicated by the high end of the color range.
If a Cesarean section (C-section) delivery is a possibility, vaginal cytology can be done daily to help safely time the C-section. Slides can be made at home, after instructions are provided by your veterinarian. Once breeding is complete, bring the slides to the clinic for evaluation. Cesarean sections are usually scheduled for 57 days from the onset of diestrus and diestrus can be determined from the vaginal cytology. This technique provides for maximal survival of pups by timing surgery appropriately. In some instances, progesterone levels may also be measured at the end of the pregnancy to aid in timing of the C-section.
An abdominal ultrasound to confirm the pregnancy can be done at Day 28. Puppy counts are not accurate at this time, however. On Day 52 from the onset of diestrus, the bitch can be radiographed (x-rayed) for a puppy count. The radiograph does not harm the developing puppies but allows for an accurate puppy count. Counting the puppies allows dystocia to be recognized early if there is a delay between puppies at the time of whelping. The radiograph also allows puppy size to be evaluated, to estimate whether the puppies will likely be able to pass through the pelvic canal.
Dystocia is identified as the bitch going for more than 3 hours without producing a pup, straining on the part of the bitch for 1 hour without producing a pup, or development of a black, green, or red vulvar discharge before any pups are produced. This discharge indicates placental detachment. Call your veterinarian if you suspect your bitch is experiencing dystocia.
It is recommended that all breeding dogs be tested annually for brucellosis. Stud dogs that breed frequently should be tested twice yearly. Vaginal cultures on bitches are not necessary unless infertility is suspected.
Management of the Pregnant Bitch
An initial pre-breeding visit involves a complete physical examination of the bitch, with submission of a complete blood count and biochemistry profile, especially in older bitches. If the bitch is showing any signs of heat, vaginal cytology is performed and a progesterone testing plan is established.
An abdominal ultrasound is usually performed about Day 28-30 after the last breeding to diagnose whether the bitch is pregnant. Plain radiography (x-rays) can identify fetal skeletons at Days 43-45 of gestation. Radiographs may be delayed until Day 50-52 of gestation to avoid false-negative results that can occur earlier than Day 50. The bitch should be fasted the morning of the radiographs so a full stomach does not interfere with interpretation of the films.
In obese bitches, weight reduction before breeding improves conception rates and decreases the risks of poor lactation and dystocia. Weight loss is never attempted during pregnancy. During the first 3 weeks of pregnancy, the well-conditioned bitch may experience little weight gain. Consumption of a high-quality, adult food is sufficient for the first 2/3 of the pregnancy. Overfeeding during the first 2/3 of pregnancy is a common tendency. Bitches that become pregnant that are excessively thin should eat a growth or performance diet to correct their low body condition.
Around Week 3 of gestation many bitches experience appetite loss that may persist for several days to a week. Mild gastrointestinal (GI) upset and nausea may also occur. Appetite typically returns to normal about Week 4.
Energy requirements increase, as well as the need for more proteins and carbohydrates, during the last half of pregnancy. Percentage of calories from dietary protein should be 29-32%, from carbohydrates should be 40%, and from fat should be 18%. Gradually increase the amount fed for pregnancy and/or lactation. A rapid diet change may lead to GI upset. The amount of food needed during the last 1/3 of gestation increases in proportion to litter size and growth of the fetuses. Gradually increase the volume fed by 25-30% over the last 4 weeks prior to the whelping date. Feeding multiple small meals is sometimes better, especially if the litter size is large. Many, but not all bitches stop eating 24-48 hours before delivery. During lactation the bitch’s energy requirements are increased by 250%.
Administration of supplemental vitamins and minerals to bitches is discouraged. Few supplements are a pure source of a given nutrient. Calcium supplementation is actually contraindicated. Cottage cheese is not recommended. Increased calcium requirements are usually met by increased food consumption of a well-balanced diet. Excessive calcium intake above that provided by a high quality diet can suppress parathyroid hormone production and increase the chances for hypocalcemia (eclampsia).
Excess Vitamin A has been associated with congenital defects in the offspring, including cleft palate. Folate deficiencies have been associated with fetal defects in humans. Most premium diets provide adequate folate, but supplementation of B vitamins is not considered harmful. Dogs produce enough Vitamin C from their diet and do not require supplementation. Excess Vitamin D intake can affect calcium metabolism of the bitch and is not recommended.
Supplementation of omega-3 fatty acids maximizes cerebral and retinal development in the fetus and may even help produce larger litters with fewer stillbirths. The ideal ratio is 5:1 omega-6 to omega-3. The veterinary product, 3V Caps, provides this ratio. Most bitches should receive a fatty acid supplement.
In bitches that do not eat voluntarily, dietary supplementation is needed. In severe cases, termination of pregnancy may be needed to avoid life-threatening hypoglycemia (low blood sugar) or pregnancy toxemia. Bitches that do not receive enough carbohydrates are also more prone to pregnancy toxemia. Pregnancy toxemia causes a significant increase in stillborn puppies and neonatal death within the first 3 days of life.
Regular exercise is important during pregnancy to maintain good body condition. Brisk, short walks and short episodes of swimming are the safest forms of exercise. In late gestation, bitches with large litters require shorter walks. Advanced obedience and agility work are not recommended during pregnancy. Significant mental or physical stress should also be avoided.
Routine vaccinations should be completed before breeding. The puppy’s immune system is dependent upon high levels of antibodies passed to them in the bitch’s colostrum (the mild produced soon after birth). The amount of antibodies in colostrum is dependent upon the mother’s immune status. Administration of modified live vaccines is not recommended during pregnancy.
Infection of developing fetuses by Toxocara canis (round worm) and Ancylostoma species (hook worms) during the last trimester can be treated by administration of oral fenbendazole 50 mg/kg daily from Day 40 of gestation through Day 14 after whelping.
External parasites are best controlled by environmental management and approved topical formulas, such as Revolution or Frontline. Use of organophosphates and pyrethroids should be avoided. Heartworms do cross the placenta and pregnant bitches should be maintained on preventive agents, such as Interceptor, Sentinel, Revolution or Heartgard.
Although uncommon, some bitches do not produce progesterone levels high enough to maintain pregnancy. The progesterone level must not drop below 2 ng/ml. If the bitch has a history of losing a pregnancy or prior infertility, the progesterone level may be checked daily if it is discovered to be less than 5 ng/ml. Low progesterone levels can be treated with daily injections of progesterone in oil (2-3 mg/kg) intramuscularly (IM) or maintained with daily, oral ally-trenbolone (Regumate) at 0.88 mg/kg. Progesterone supplementation is discontinued within 72 hours of the timed whelping date.
Administration of any medication during pregnancy should be avoided unless absolutely necessary. Check with your veterinarian before administering any products, supplements or medications to the bitch.
Ovulation Timing in Dogs
Ovulation timing is important when artificial insemination (AI) techniques are used because shipped, frozen, or chilled semen have decreased survival times. Survival time is only a few days for cooled semen and as low as 12 hours for frozen semen, in contrast to fresh semen that can live for 5-11 days. Several techniques are employed to maximize conception rates and litter size when insemination techniques are used.
Day 1 of proestrus is considered the first day that any signs of heat (estrus) are noted, such as vulvar swelling or vulvar discharge. Record this day on your calendar. Five days after the onset of proestrus (Day 6), progesterone testing is started. Progesterone testing requires sending a blood sample to a referral laboratory for evaluation. The bedside progesterone tests are not accurate enough to use reliably for artificial insemination. Progesterone samples are submitted every other day until ovulation occurs, which is usually at a progesterone level of 5 ng/ml. Depending upon the laboratory results are available within a few to 24 hours. Once ovulation has occurred, insemination is planned for 3 days later. This delay allows time for shipment of frozen or chilled semen. If a second breeding is planned, it is done 48 hours after the first breeding. A progesterone sample is taken at the time of breeding to ensure levels are between 15-25 ng/ml. This range maximizes litter size and conception rates.
Vaginal cytology is combined with progesterone testing to determine when diestrus has occurred. Slides can be made at home, after instructions are provided by your veterinarian. Once breeding is complete, bring the slides to the clinic for evaluation. Cesarean sections are usually scheduled for 57 days from the onset of diestrus or 62-64 days from the time progesterone reaches 5 ng/ml. Diestrus can be determined from the vaginal cytology. This technique provides for maximal survival of pups by timing surgery appropriately.
Vaginoscopy (examination with a viewing scope) can be used to evaluate changes within the vaginal vault that occur with proestrus and estrus. Vaginoscopy is typically recommended when transcervical AI is planned.
Artificial insemination can be achieved by several techniques. A common technique is instillation of semen into the vaginal vault using a pipette. The pipette is advanced to the level of the cervix and the semen is deposited there. The bitch’s hindquarters are elevated for 15 minutes after the insemination. This technique works best with fresh semen because fresh semen lives 5-6 days. This longevity gives the semen time to cross the cervix and enter the uterus. This technique is not recommended for chilled or frozen semen.
For chilled or frozen semen transcervical or surgical insemination is recommended because these techniques deposit the semen directly into the uterus. Chilled and frozen semen do not live as long, so intrauterine deposition maximizes conception rates. Surgical insemination is best for bitches with previous infertility problems, because the uterus can be visualized and any intrauterine cysts manually broken during surgery. Surgical insemination is done under general anesthesia and requires an abdominal incision with sutures. Surgical insemination is only done once during the estrous cycle.
Transcervical insemination (TCI) offers several advantages over surgical insemination. TCI can be done without sedation in most bitches, especially if the owner is present. The procedure takes 10-15 minutes. Insemination can be done multiple times within an estrous cycle, usually 48 hours apart. The technique involves the use of a rigid viewing scope to visualize the cervix. The scope enters the vaginal vault similar to placement of the pipette for vaginal insemination. The cervix is identified through the scope and a catheter is passed through the cervix into the uterus where the semen is then deposited. Conception rates in healthy females with viable sperm reach 86% with these techniques.
Litter survival rates are higher with properly timed Cesarean sections (C-sections). C-sections are often done 57 days after the onset of diestrus. An abdominal radiograph (x-ray) is done at Day 52 for a puppy count. An abdominal ultrasound to confirm the pregnancy can be done at Day 28.
If natural whelping is planned, the radiograph allows evaluation of the size of the puppies to estimate whether they will be able to pass through the pelvic canal. The radiograph is not harmful to the developing pups. Dystocia is identified as the bitch going for more than 3 hours without producing a pup, straining on the part of the bitch for 1 hour without producing a pup, or development of a black, green, or red vulvar discharge before any pups are produced. This discharge indicates placental detachment. Call your veterinarian if you suspect your bitch is experiencing dystocia.
Preparing for your dog's labor and puppy care can be both exciting and fun; still, awareness of potential problems is of paramount importance. It is a good idea to keep track of your dog's breeding date so as to know when to expect what.
After about 35 days of pregnancy, the mother's caloric requirements will begin to increase. In general, she should require about twice as much food as usual whereas, when she begins nursing, she will need three times as much food. The best nutritional plan is to buy a dog food approved for growth (i.e. puppy food) and feed according to the package; such diets are balanced and require no supplementation, plus they typically have the extra calories needed by the pregnant or nursing mother. Exercise of the pregnant bitch need not be restricted until after the first 4 to 6 weeks of pregnancy. Do not supplement calcium as this can cause metabolic imbalances; also, excess vitamins may be harmful to the puppies.
Sometime around the 45th day, your dog should be examined by a veterinarian. At this time, the skeletons of the unborn pups will have mineralized and are thus visible on a radiograph. Your dog's abdomen should be x-rayed so that you know how many pups to expect. Ultrasound may be used to confirm pregnancy much earlier (after 25 days, the embryonic heart may be seen beating) but it is more difficult to count the number of pups using this method. A general pregnancy blood test can be performed around day 35 just to confirm whether or not she is pregnant but neither this nor ultrasound will tell you how many puppies to expect; only radiographs can do that.
A comfortable area should be set aside for whelping and raising the puppies. The bitch should feel at home here and should be able to come and go as she likes while the puppies must remain confined.
It is important that the mother dog be isolated from all other dogs for 3 weeks prior to labor through 3 weeks after delivery to prevent herpes infection. Herpes is spread by sniffing and licking between two dogs. Adult dogs rarely have any symptoms but the newborn or unborn puppies generally die.
A dog’s gestation period is considered to be 63 days though this is not written in stone and a normal range might be 58 to 68 days.
When your dog's due date is approaching, you should begin monitoring her rectal temperature. When her temperature drops below 100° F (normal canine temperature is 101-102° F), labor may be expected within 24 hours.
The First Stage of Labor
During this stage, uterine contractions begin. The bitch will appear restless and may pace, dig, shiver, pant, or even vomit. This is all normal and all an owner can do is see that she has water available should she want it. This stage of labor is long, lasting 6 to 12 hours and culminates with full dilation of the cervix in preparation to expel a puppy.
The Second and Third Stages of Labor
The second stage is the hard labor stage in which the puppy is expelled. The third stage refers to the expulsion of the placenta and afterbirth. Each pup may not be followed by afterbirth; the mother may pass two pups and then two placentas. This is normal.
Puppies are born covered in membranes that must be cleaned away or the pup will suffocate. The mother will bite and lick the membranes away. Allow her a minute or two after birth to do this; if she does not do it, then you must clean the pup for her. Simply remove the slippery covering and rub the puppy with a clean towel. The umbilical cord may be tied in a knot about one inch from the pup and cut with scissors on the far side of the knot. Be careful not to pull on the umbilical cord as this can injure the puppy. The mother may want to eat the placenta but this is probably not a good idea as vomiting it up later is common; it is best to clean away the placenta yourself.
Expect one pup every 45 to 60 minutes with 10 to 30 minutes of hard straining. It is normal for bitches to take a rest partway through delivery, and she may not strain at all for up to 4 hours between pups. If she is seen straining hard for over one hour or if she takes longer than a 4 hour break, a veterinarian should be consulted.
Expect some puppies (probably half of them) to be born tail first. This is not abnormal for dogs.
CALL YOUR VETERINARIAN IF: