Canine pyometra

Pyometra, literally meaning pus in the uterus, is a common disease entity of intact bitches. Similar conditions occur, including hydrometra and mucometra [De Bosschere H, Ducatelle R, Vermeirsch H, Van Den Broeck W, Coryn M. Cystic endometrial hyperplasia-pyometra complex in the bitch: should the two entities be disconnected? Theriogenology 2001;55:1509-19]. The exact etiology is unknown; however the repeated and prolonged response to estrogen followed by long intervals of progesterone dominance in the intact bitch leads to hormonally mediated changes in the endometrium. The endometrium changes when impacted by bacterial infiltration; changes in endometrial steroid receptors can result in the clinical syndrome described as pyometra. This paper will describe the signalment, risk factors, prevalence, proposed etiologic events, and both medical and surgical therapies. In addition, the prognosis for successful outcome and effects on future reproduction will also be described.     

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.     

Effect of administration of prostaglandin F2alpha or presence of an estrous teaser bitch on characteristics of the canine ejaculate

Semen was collected from eight dogs after SC administration of 0.1mg/kg PGF2alpha or 0.6 mL 0.9% NaCl solution 15 min prior to collection in the presence or absence of an estrous teaser bitch (switchback design; all dogs given all four treatments in random sequence). There were more spermatozoa (P=0.02) in ejaculates collected after administration of PGF2alpha in the presence of an estrous teaser bitch ((852+/-736)x10(6), mean+/-S.D.) than in ejaculates collected in saline-treated dogs in the absence of a teaser bitch ((371+/-620)x10(6)). However, the number of spermatozoa in the ejaculate of dogs given PGF2alpha in the absence of a teaser bitch and in dogs given saline in the presence of a teaser bitch ((556+/-494 and 600+/-622)x10(6), respectively) were not significantly different from each other or from the other two groups. The percentage of morphologically normal spermatozoa did not vary by treatment (P=0.51). In conclusion, treatment with PGF2alpha and presence of a teaser bitch had an additive effect on the number of spermatozoa. This, coupled with relatively minor side-effects, suggests this is a useful technique to increase number of spermatozoa in a single canine ejaculate.     

Prenatal and lactational transmission of Toxocara canis and Ancylostoma caninum: experimental infection of the bitch before pregnancy

Breeding of five parasite-free and five experimentally infected (6000 Toxocara canis eggs orally and 2500 Ancylostoma caninum larvae subcutaneously) beagle bitches was done so that pairs of bitches (1 uninfected, 1 infected) whelped simultaneously. Pups born to an infected bitch were removed at birth and nursed by the paired uninfected bitch until 4 weeks of age when pups were necropsied to determine the number of parasites they had acquired prenatally from their infected mother. Pups born to the parasite-free bitch were nursed by the infected bitch until necropsied at 4 weeks of age to determine the number of parasites passed via the lactational route. Of 680 ascarids transmitted to pups by either route, 98.5% were transmitted prenatally and 1.5% lactationally. Transmission of 2746 hookworms to 22 pups occurred solely by the lactational route; prenatal transmission of this parasite did not occur in any of the 25 pups born to infected bitches.     

Estimation of gestational age and assessment of canine fetal maturation using radiology and ultrasonography: a review

Since the duration of pregnancy in the bitch is relatively short, it is critical that fetuses are fully mature prior to delivery for them to survive. For breeders to be able to prepare for normal whelpings and align medical care in case of emergency, an estimated due date is necessary. In cases where ovulation timing is lacking and there is a singleton fetus or oversize fetuses, it is necessary to ascertain gestational age prior to setting the date of Cesarean section. In high-risk pregnancies, where there is poor or no ovulation timing, determination of fetal maturation and gestational age will assist in determining if pregnancy has progressed long enough to allow delivery of viable puppies. In cases where bitches are receiving supplemental progesterone for pregnancy maintenance medications must be discontinued at an appropriate time to permit delivery of viable puppies. It also allows for estimation of the likelihood of fetal survival if the pregnancy is terminated due to failing bitch health, with subsequent surgical delivery of the fetuses. Use of breeding dates alone does not provide due dates with adequate accuracy. In cases where there has been inadequate or no breeding management or ovulation timing, estimation of due date can be performed at the time of pregnancy diagnosis, or closer to term. Radiography can be used to confirm pregnancy and facilitate determination of gestational age, beginning 45d after the LH surge. Ultrasonography can be used from 19 to 21d after the LH surge to term to confirm pregnancy and predict gestational age, and from 25 or 26d to term to assess fetal viability and fetal stress.     

Fatal experimental transplacental Babesia gibsoni infections in dogs

A Babesia gibsoni infected bitch was mated with an uninfected dog in order to determine whether this parasite could be vertically transmitted. The bitch delivered a litter of four live and one stillborn pup. The four pups died from congenital babesiosis between 14 and 39 days post-birth. Babesia gibsoni DNA was detected in tissue from all five pups. These results show that vertical transmission occurred by the uterine route and not via the transmammary route. This is the first confirmed report of transplacental Babesia infection in any animal species.     

Dietary supplement Standard Reference Materials

A new category of Standard Reference Materials (SRMs) based on dietary supplements is under development by the National Institute of Standards and Technology (NIST), with certified values for organic constituents and selected trace elements. These materials are provided primarily for use in method development and as control materials. The SRMs will assist manufacturers of dietary supplements in characterizing raw materials for potency, authenticity, and contamination or adulteration. In addition, the SRMs will assist in assessment of consistency and quality in finished products. The goal of this ongoing effort is to provide tools to the dietary supplement industry and measurement communities that will lead to improved quality of dietary supplements, and ultimately reduce public health risks that could potentially be associated with these products.     

Fertile estrus induced in bitches by bromocryptine, a dopamine agonist: a clinical trial

The dopamine agonist bromocryptine, probably through amplifying gonadotroph (mainly FSH) secretion, was found to be suitable for provoking fertile estrus during the anestrous phase in bitches without functional cycles and/or ovarian activity. We studied estrus induction in 48 bitches after treatment with semisynthetic ergot alkaloid bromocryptine. For habituation a fractional dose of 0.3 mg/bitch was administered for three days followed by larger doses within the range of 0.6 to 2.5 mg/bitch by selecting dose rates on the basis of individual responsiveness and body weight. The long-term daily bromocryptine dose did not exceed 0.6 mg/bitch and 2.5 mg/bitch in small and large sized bitches, respectively. Gradual habituation and individual dose rates have almost completely eliminated the unwanted side effect of emesis. The period between treatment and onset of estrus varied but the average was 19 days. After the onset of estrus bromocryptine administration was usually continued for another 3 to 6 days. Occurrences of estrus, ovulation and pregnancy were monitored by cytological evaluation of vaginal epithelium, rapid ELISA for plasma progesterone and ultrasonography, respectively. Samples for progesterone were taken on Days 7, 9, 12 and 15 and sonograms of ovarian follicles and of fetuses were taken on Days 0, 22 and 35. The bitches involved in the study either regular or irregular cycles. Bromocryptine treatment induced estrus in all of the bitches including 40 of 48 (83%) with ovulation within a regular estrus and 6 of 48 (12.5%) that showed estrus but did not ovulate. Mating or artificial insemination of bitches in their fertile periods twice at two day intervals resulted in an 83% pregnancy rate (40 cases) and 39 (97.5%) of them gave birth to puppies. However, the average litter size was small with 4.8 +/- 1.6 pups.     

First report of vaginal prolapse in a bitch treated with oestrogen

Vaginal prolapse is the protrusion of edematous vaginal tissue into and through the opening of the vulva occurring during the pro-oestrus and oestrus stages of the sexual cycle. True vaginal prolapse may occur near parturition, as the concentration of serum progesterone declines and the concentration of serum oestrogen increases. In a bitch, true vaginal prolapse is a very rare condition. This case report describes an 18-month-old crossbreed bitch, weighing 40 kg presented with type III vaginal prolapse. The patient had developed vaginal prolapse after receiving oestrogen in order to oestrus induction. Subsequent to unsuccessful attempts for repositioning, ovariohysterectomy (OHE), circumferential excision of the prolapsed tissue and finally vulvoplasty were performed. There was no evidence of recurrence of the prolapse during 30 days after surgery. This case report describes type III vaginal prolapse as an unusual side effect of oestrus induction hormonal therapy in the bitch.     

Electrical resistance of vaginal secretion in the bitch

Five multiparous and four nulliparous bitches had the electrical resistance of vaginal secretions measured by an ohmmeter. The bitches were examined daily, starting on the first day of vulval bleeding and continuing until the first day when exfoliated vaginal epithelial cells became predominantly noncornified. In contrast to cattle, sheep, and swine, the electrical resistance of the vaginal secretions in the bitch increases during pro-oestrus and continues to be high while the bitch is showing oestrous behaviour and a high percentage of eosinophilic superficial cells in the vaginal smear. Ovulation, as determined by a rise of serum progesterone above 5 ng/ml, occurs within the period of elevated resistance. Optimal conditions for conceptions coincide with the last 3 d of elevated resistance.     

The value of canine semen evaluation for practitioners

Compared to human medicine, little is known in canine medicine regarding specific findings on semen evaluation and their correlation with fertility. Suggestions to optimize quality of semen evaluation in veterinary practice include creating standardized protocols for evaluation of all semen parameters and updating those protocols as needed; creating some form of quality control for the clinic laboratory; educating owners about our inability to predict with 100% accuracy whether dogs with poor semen quality never could impregnate a bitch or whether dogs with excellent semen quality always could impregnate a bitch; and generating protocols for further diagnostic work-up for those dogs with abnormal semen quality.     

Transport of Radiopaque Fluid into the Uterus After Vaginal Deposition in the Oestrous Bitch

A limited number of studies have been published concerning intrauterine infusions in the bitch, presumably because it is difficult to pass a catheter into the canine cervix. Cobb (1959) designed an apparatus for hysterosalpingography with which he reported fairly easy catheterization of the cervical canal in the anaesthetized bitch. Recent advances made in the field of deepfreezing of dog semen have emphasized the need for a simple method for intrauterine infusion in the unanaesthetized bitch. The first successful insemination with frozen dog semen was reported in 1969 by Seager. The semen was frozen in pellets and deposited vaginally. Over a six-year period 61 (39.1 %) out of 156 bitches inseminated with this method became pregnant (Seager et al. 1975). Andersen (1972), however, when inseminating dog semen frozen in French straws, reported no success after vaginal deposition of the thawed semen. Based on experience with insemination in Blue foxes Andersen (1975) developed a special catheter which he could introduce through the cervix to deposit the semen into the corpus uteri without anaesthetizing the bitches. With this method 19 (73.1 %) out of 26 bitches became pregnant (Andersen 1977, personal communication). This method of passing the catheter through the cervix requires training and the method is impractical in nervous or obese bitches in which palpation of the abdomen is difficult or impossible. In order to fully use the advantages offered to the dog breeders by deep-freezing of dog semen, it is necessary to develop a simple method of inseminating the bitch that can be employed by practising veterinarians without previous special training. The present investigation was undertaken as an introduction to further studies of the problems related to the use of frozen dog semen.     

Proposed rule: current good manufacturing practice in manufacturing, packing, or holding dietary ingredients and dietary supplements

The Dietary Supplement Health and Education Act (DSHEA) was enacted in October 1994 to promote the health of Americans by ensuring easier access to safe dietary supplements. Many supplements such as vitamins, minerals, herbs and amino acids have been reported to be helpful in chronic conditions (i.e., heart disease, cancer and osteoporosis). Under DSHEA, dietary supplements can be marketed without prior FDA approval; the burden is on this agency to show that a marketed dietary supplement is unsafe. However, DSHEA retained the FDA's authority to issue regulations that require the manufacture of dietary supplements be in compliance with current good manufacturing practice (cGMP) standards, which are needed to ensure their quality. Several quality-related concerns of marketed dietary supplements that came to light since the passage of DSHEA prompted the FDA in 2003 to propose rules for cGMP for the manufacture, packaging and holding (storage) of dietary supplements. This review will present the highlights of these proposed rules, focusing on the legislative history of DSHEA, rationale for proposing cGMPs along with a general discussion of the specific requirements. Given the voluminous nature of the specific details, the reader is directed to the pertinent FDA publications for details. In this analysis, selected scientific and legal issues are also discussed to promote a better understanding and implications of these rules.     

Robertsonian translocation (8;14) in an infertile bitch (Canis familiaris)

A new case of a Robertsonian translocation diagnosed in an infertile bitch of West Highland White Terrier breed is reported. Cytogenetic analyses were performed with the use of Giemsa staining, Q-, C- and Ag-I banding techniques and FISH with canine whole X chromosome paint. The karyotype of this bitch was described as 77,XX der (8;14)(q10;q10).     

Gnathostoma binucleatum: Pathological and parasitological aspects in experimentally infected dogs

Lesions and antibody kinetics produced by inoculation of Gnathostoma binucleatum larvae into dogs are described, as well as the morphology of the recovered parasites. In four out of five infected bitches parasite phases were found in the stomach. Only one bitch eliminated eggs and adult parasite phases in feces. In this bitch, the prepatency period lasted 22 weeks and the patency period 14 weeks. Necropsy results showed a copiously vascularized 8-cm diameter fibrous nodule lodged in the greater curvature of the stomach. Two bitches that eliminated no eggs showed 1- to 2-cm diameter nodules on the gastric wall, with five juvenile phases in each. One bitch that eliminated no eggs and exhibited no gastric nodules showed juvenile parasites on the gastric wall. Results confirm dogs as definitive hosts of this parasite. New data on the pathological and parasitological aspects of canine gnathostomosis are presented.     

Challenges in small animal parturition--timing elective and emergency cesarian sections

Given the societal emphasis placed on the deliberate breeding of purebred animals, the practitioner today is faced with issues relative to successful parturition in these animals. Today, the serious hobby breeder expects to use planned breeding management to result in a high conception and pregnancy rate and survival rates of offspring that may exceed published parameters. These clients may elect to schedule cesarean section to maximize puppy survival and assure that they have access to quality veterinary care. Using a combination of hormone assays, temperature changes in the dam and carefully timed and documented breeding management, a cesarean section can be planned. Emergency cesarean sections will still be required for the bitch that experiences dystocia or a medical condition that warrants intervention. Timed cesarean section results in a favorable medical outcome for the dam and litter and a better financial outcome for the owner.     

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.     

Immunohistochemical localization of VEGF and its receptors in the corpus luteum of the bitch during diestrus and anestrus

The corpus luteum (CL) is a temporary endocrine gland, whose life span depends on the interaction of luteotrophic and luteolytic factors. Since development and maintenance of CL is based on angiogenesis, angiogenic growth factors may play a role in CL-function of the bitch, as described for other species. The aim of this study was to detect the presence of the vascular endothelial growth factor (VEGF) system in the bitch CL throughout diestrus and early anestrus. For that purpose, blood samples from 24 bitches were collected and analyzed for progesterone to determine ovulation time and the animals were subjected to ovariosalpingohysterectomy 10, 20, 30, 40, 50, 60 or 70 days after ovulation. The corpora lutea were fixed in formalin and embedded in Paraplast resin. Five micrometers sections were submitted to standard immunohistochemistry protocol using three primary antibodies (SC-315, SC-316 and VG76e) for detection of kinase domain region (KDR), fms-like tyrosine kinase 1 (Flt-1) and VEGF, respectively. The VEGF system expression could be detected in all diestrus stages in endothelial as well as luteal cells (responsible for blood vessel formation and progesterone production, respectively), indicating time dependent changes: immunostaining tended to increase from Day 10 to 50 and to decrease until Day 70 post-ovulation. In the CL of the bitch, structure related cells, like pericytes and stroma cells, expressed it in determined time points of diestrus with little intensity variation. We concluded that VEGF might have a modulatory effect in the CL of the dog acting as paracrine and autocrine factor through its receptors, Flt-1 and KDR.     

X trisomy in an infertile bitch: cytogenetic, anatomic, and histologic studies

Three copies of the X chromosome were identified in a 5-year-old mixed breed infertile bitch. One year after the cytogenetic examination, the bitch died due to gastritis hemorrhagica, an inflammation of the mucus coat of the stomach. Dental studies showed congenital lack of some premolar and molar teeth. Ovaries were of normal shape and size. Also, histologic sections of the ovaries revealed their normal structure, with two corpora lutea and primary follicles. Phenotypic effects of X trisomy are discussed.     

Fertility control in the bitch by active immunization with porcine zonae pellucidae: use of different adjuvants and patterns of estradiol and progesterone levels in estrous cycles

To determine the changes in patterns of 17 beta-estradiol and progesterone levels underlying abnormal cycles in bitches immunized with solubilized crude porcine zonae pellucidae (cPZP), to attempt to circumvent these problems by immunizing with a purified zona fraction (pPZP), and to test the effectiveness of different adjuvants, bitches were immunized with cPZP or pPZP 2-6 times with no adjuvant, Freund's adjuvant, alum adjuvant, or the adjuvant CP-20,961. The bitch immunized without adjuvant had a low titer with a normal cycle and fertility. Immunization with cPZP and adjuvant produced moderate to high titers of antizona antibodies and infertility. Bitches with high titers experienced abnormal estrous cycles. Estradiol rose during proestrus, but instead of falling sharply in early estrus as in controls, it remained elevated. Progesterone did not rise. The moderate-titered bitches had normal cycles and steroid patterns. Bitches immunized with pPZP had moderate titers. Cycles were normal after 3 injections, but after 6 injections one bitch had an abnormal cycle. One pPZP-immunized bitch remained fertile but the others were infertile. Alum was the mildest adjuvant, causing no injection site lesions, but the highest titers occurred with Freund's and CP-20,961 adjuvants. All three adjuvants induced titers sufficient to inhibit fertility. Infertility in bitches immunized with PZP may be due to prevention of zona penetration, because their antisera inhibited zona penetration of oocytes by spermatozoa in vitro. However, alterations in ovarian function preventing ovulation and luteinization could be involved in high-titered bitches.