Canine embryonic and fetal development: a review.

The progression from a fertilized oocyte to a newborn puppy is a remarkable phenomenon that occurs in a period of approximately two months. Embryonic development encompasses the period of time at which three germ layers differentiate: ectoderm, mesoderm, and endoderm. Organ systems are formed from these germ layers, with most of the reproductive tract being derived from mesoderm. Organogenesis is complete prior to the fetal stage in canine embryos, but sexual differentiation occurs during the fetal stage. Sexual differentiation is a well-coordinated progression of events that is directed initially by the genotype of the developing embryo and fetus. Developing fetuses are inherently female and will develop as such in the absence of a Y chromosome. Male fetuses develop as the Y chromosome causes regression of the female duct system and development of the male duct system. Testicular descent in the canine begins in the fetal stage, but is not completed until after birth.

Clinical presentation of canine pyometra and mucometra: a review.

Cystic endometrial hyperplasia (CEH) in the bitch can result in either pyometra, hematometra, or hydrometra, and many facets of these uterine diseases can make them difficult to differentiate. The conditions differ in their systemic effects, since pyometra, particularly closed-cervix pyometra, can be a life-threatening condition that must be recognized, managed, and treated expeditiously. Mucometra is an accumulation of sterile intraluminal mucoid fluid, hematometra is an accumulation of sterile, bloody fluid, and hydrometra is an accumulation of sterile, watery fluid; none of which have any significant systemic outward clinical signs. This paper will describe the definitions, signalment, historical findings, incidence, clinical signs, physical exam findings, and diagnostic findings in canine pyometra and mucometra, and hematometra and hydrometra.

Medical management of canine and feline dystocia.

When dystocia is diagnosed in the bitch or queen, two forms of treatment exist: medical or surgical therapy. Medical management of dystocia has the advantage of aiding completion of the parturition process without surgery or anesthesia. However, since not all cases of dystocia can be managed medically, educated and careful decision making is required prior to instituting medical management in cases of dystocia. Improper medical treatment, especially when surgical management is clinically indicated, can result in compromise and even death of the dam and fetuses. This paper focuses on the decision making necessary prior to instituting medical management for cases of dystocia in both bitches and queens, and describes available therapeutics.

Bacterial and protozoal causes of pregnancy loss in the bitch and queen.

Several bacterial species have been implicated in canine and feline pregnancy loss. Brucella canis is one of the more important bacterial infectious agents that cause pregnancy loss in the bitch. Brucella has been documented in the queen but in general infectious abortion from bacteria and protozoal agents is uncommon in the species. Protozoal causes of pregnancy loss in the bitch and queen are less common than in other species. Etiology, clinical signs, diagnosis and treatment of bacterial and protozoal causes of pregnancy loss in the bitch and queen are reviewed. Veterinary practitioners should be aware that many of these organisms have zoonotic potential.

Single, transcervical insemination using frozen-thawed semen in the Greyhound: a case series study.

Transcervical insemination (TCI) has generated recent interest as an assisted reproductive technique in the dog. A case series study was performed to determine if TCI using frozen-thawed semen was a viable technique to offer in a general veterinary practice setting. Over a period exceeding 28 months, 137 Greyhound bitches were presented for assisted breeding. A single, timed insemination using a rigid cystoscope to aid in transcervical deposition of a frozen-thawed semen dose was given within 72 h after the behaviorally estrual bitch had a > 4 ng/mL serum progesterone concentration and estrus-categorized vaginal cytology. Litter size, pregnancy and whelping rate were collected; their association to semen center and stud dog were quantified. Of the 137 bitches, 117 were bred for one cycle and 20 were bred for two or more cycles, giving a total of 161 single, timed inseminations. Pregnancy rate was 89.4%, with 141 (87.5%) whelping. Litter size was 6.9+/-2.7 (mean+/-S.D.) pups. Semen center (P=0.84) and stud (P=0.79) had no effect on pregnancy. These results were quite favorable when compared to prior TCI studies, and are possibly due to the use of a single breed (i.e., Greyhound) with good fertility. This study supported the application of TCI, in Greyhounds, as a successful and viable service to offer in private practice. Additionally, these results have value in their use for benchmarking future breed-specific and TCI research. Serendipitously, the apparent fecundity results obtained in this observational study suggests a possible greater appreciation be given to breed composition and choice in assisted reproductive technique studies.