If it only told you how to keep them separated!

Canine Estrous Cycle or Heat Cycle
Normal Gestation (Pregnancy) In Dogs
Gestation is the period when the young are developing in the mother’s uterus. In dogs, gestation normally lasts 9 weeks (63 days). However, puppies may be delivered between 58 and 68 days.

Diagnosis of Pregnancy: There are no practical blood or urine tests available to confirm pregnancy in the dog. The earliest possible time of diagnosis may be 26-35 days after breeding, when the doctor may be able to detect pregnancy (85% accuracy) by feeling the abdomen. Diagnosis by x-rays is usually possible after 45 days (95% accuracy for determining the number of puppies).

Physical Changes: During the first five weeks of pregnancy, there are few noticeable changes. After the fifth week, you may notice weight gain, especially with large litters. If only one or two pups are present, the mother may gain little weight until shortly before birth. Abdominal enlargement is generally obvious in the last three weeks. The mammary glands may begin to enlarge 35 days into the pregnancy, but usually development is not obvious until 45 days. Milk may be present as early as seven to nine days before delivery, but usually it is not produced until one to two days before delivery.

Behavioral Changes: During pregnancy, the female dog may show a change in behavior, especially in the last few weeks. As the uterus enlarges with the developing puppies, your dog may become restless, seek seclusion and in the last few days, soil the house. She may shred papers, blankets or bedding in an attempt at “nest building” in the last weeks. During the last two weeks, your dog may become irritable and should avoid contact with small children.

Nutrition: Good nutrition is essential for healthy puppies and mothers. During the first four weeks, nutritional needs change little, but feeding small amounts of high protein supplements, such as eggs, lean muscle meats (not pork) or liver is a good practice. During the last five weeks, your dog’s nutritional needs nearly double. Feed increased amounts of food in several small meals each day. Fresh water should always be available, since fluid needs are greatly increased. Feeding puppy food through the end of lactation (nursing) is always a good practice.

Exercise: Moderate exercise is the proper approach. Neither forced rest nor strenuous exercise is a good idea. Short periods of gentle play and short walks are good.

Canine Puberty
Information taken from: LSU School of Veterinary Medicine

Normal puberty can occur at 6-24 months.
Larger dogs tend to reach puberty at an older age than smaller dogs.
First estrus tends to be irregular.
Do not base fertility on what happens during the first heat.
Split heats are common during the first estrus.
The bitch bleeds, stops bleeding and then returns to heat around 6 weeks later. Fertility is normal for these heats, however.
Do not breed on first heat. Breeding on the first heat may increase the risk of dystocia (an abnormal or difficult birth or labour).
Delayed puberty is rare in the bitch.
Nutritionally delayed puberty has a poor prognosis for future fertility.
Induction of the first estrus can sometimes be hastened by housing the bitch with a kennelmate that is in proestrus (the first stage of heat cycle. The heat cycle lasts from 18 to 21 days.)


The Canine Estrous Cycle: Staging Using Vaginal Cytological Examination by Valerie R. Beimborn, DVM; Heather L. Tarpley, DVM; Perry J. Bain, DVM, PhD; and Kenneth S. Latimer, DVM, PhD / Class of 2003, Ross University, School of Veterinary Medicine, St. Kitts, West Indies (Beimborn) and Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602-7388 (Tarpley, Bain, Latimer)

Introduction: Vaginal cytology is a simple technique that can be used by practitioners to help characterize stages of the reproductive cycle of the bitch or to evaluate certain diseases of the genital tract. Vaginal cytology usually is used in conjunction with the physical examination, clinical history, vaginoscopy, and hormonal assays to determine the stage of the reproductive cycle. This is especially important if artificial insemination is to be performed. Other uses of vaginal cytology and ancillary testing include determination of the whelping date, diagnosis of inflammation of the vagina, and identification of some types of neoplasia involving the vaginal vault and urethral orifice.

Estrous Cycle: The estrous cycle of the bitch contains four distinct stages that can be followed cytologically (Table 1). These stages include proestrus, estrus, diestrus, and anestrus. For some simplification and indication of which structures predominate throughout the cycle, these four stages may be grouped into the follicular phase (proestrus and estrus) or the luteal phase (diestrus and anestrus). The bitch frequently has been classified as monocyclic or having a reproductive cycle that lacks frequent, recurring periods of heat and has a long period of anestrus regardless of pregnancy status.

Proestrus: Proestrus typically lasts about 9 days. This is the reproductive phase that immediately precedes estrus. Estradiol concentration increases as ovarian follicules mature and the uterus enlarges. The vaginal epithelium proliferates accompanied by diapedesis of erythrocytes from uterine capillaries. Thus, erythrocytes account for most of the cells observed on vaginal smears at this reproductive stage. Grossly, vulvar edema, hyperemia, and a serosanguineous discharge occur.7,8

Estrus: Typically, estrus lasts for about 9 days. Estrus is characterized by the period of acceptance of the male by the bitch. The female will seek out males and stand for them prior to copulation. This stage of the reproductive cycle is difficult to determine cytologically because distinguish features are only present microscopically at the beginning and the end of estrus. During estrus, glandular secretions increase, the vaginal epithelium becomes hyperemic, and ovulation occurs. This stage of the reproductive cycle is influenced mainly by estrogens. The interval between successive estrus cycles is typically seven months.

Diestrus: This is the period where corpora lutea (CL) are present. The CL are fully functional and secrete increased large quantities of progesterone. During this phase of the reproductive cycle, the bitch refuses to accept the sexual advances of the dog. Physiologically, the uterine glands undergo hypertrophy and hyperplasia. The cervix constricts and vaginal secretions become tenacious. The length of diestrus is variable; however, regression of CL requires approximately 70-80 days.

Anestrus: Anestrus is a prolonged period of sexual rest where the reproductive system is quiescent. Secretions are minimal and very tenacious or absent. The cervix is tightly constricted and the vaginal mucosa is pale.

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