Associations between memory performance and Bifidobacterium pseudolongum abundance in the canine gut microbiome.

Memory has been identified as the least heritable cognitive trait in canines, suggesting a significant influence of non-genetic factors. We observed a trend that overall memory scores (OMS) improve with age in a cohort of 27 young dogs, but considerable plasticity exists. Employing linear discriminant analysis of gut microbiome data from dogs exhibiting low and high OMS, a single bacterial species, Bifidobacterium pseudolongum, was identified and confirmed to be correlated with elevated OMS. Subsequent analysis using a random forest regression model revealed that sex, litter, and breed identity had minimal predictive importance. Age had some predictive value but failed to achieve statistical significance in this dataset. In sharp contrast, the abundance of 17 bacterial taxa in the microbiome showed a stronger predictive capacity for memory performance. Our findings provide insights into microbiome underpinnings of mammalian cognitive functions and suggest avenues for developing psychobiotics to enhance canine memory and learning.

Breeding Program Management.

Managing a colony of high-quality, purpose-bred dogs requires strategic organization and planning. Because current demand for working dogs exceeds the supply available, production success should be maximized. Quality should always be emphasized over quantity, especially for the selection of breeding stock. Puppy development plans should take into account the 4 unique phases of puppy development. Many factors influencing breeding decisions are discussed in this article, based on lessons learned from the Canine Performance Sciences program at Auburn University, a medium-sized production colony in its twentieth year that has produced 140 litters of the highest-quality purpose-bred working dogs.

Production and Reproductive Management.

Programs breeding high-quality dogs are now able to use newer technologies in order to maximize use of genetic material and improve the efficiency of the production program. Missed estrus cycles and failure to conceive are costly in canine production programs, and parameters should be established to help minimize these failures. This article outlines lessons learned over the last 20 years in a medium-sized production program and also reviews other current production programs. Common pitfalls are discussed, including the implications of each, as well as management strategies to help avoid pitfalls.

Equine endometrial development during late fetal and postnatal periods.

Equine uterine development, including endometrial histogenesis, begins prenatally and is completed postnatally. Little is known about this process in the horse. Uterine tissue was acquired from 38 foals, ranging in developmental age from gestational day (GD) 300 to postnatal day (PND) 180, for assessment of endometrial histogenesis. Patterns of endometrial cell proliferation were evaluated by multispectral imaging of uterine tissue sections stained immunofluorescently for Ki-67. Labeling index (LI, % labeled cells) for Ki-67 was calculated for each endometrial cell compartment (luminal epithelium, glandular epithelium, stroma). Histologically, nascent endometrial glands were present in all pre- and postnatal uterine tissues. Overall, Ki-67 LI increased (P < 0.0001) from the pre-to postnatal periods, and was higher (P < 0.0001) in epithelium as compared to stroma. Postnatally, endometrial Ki-67 LI increased (P < 0.0001) from week 1 to week 24. Our findings confirm that, in contrast to neonatal patterns of uterine development described for domestic ungulates, equine endometrial histogenesis begins prenatally, marked by the appearance of uterine glands as early as GD 300. Epithelial proliferation associated with maturation of the equine endometrium is pronounced by postnatal week 24.

Small Animal Neonatal Health.

Although most veterinarians have been caring for neonates successfully for several years, it is often good to review our methods and aim to incorporate new practices that will increase survivability, especially of the weaker neonates. These tips are easy to incorporate and do not require radical change by the doctors or staff. Armed with some key pearls of neonatal knowledge and basic clinical skills, one can successfully prevent and treat the most common clinical presentations of neonatal puppies and kittens.

Breeding Soundness Examination of the Bitch.

A breeding soundness examination is a vital part of any breeding program. These examinations are not performed as frequently in the bitch as they are in the male dog. They allow clinicians to identify any problems at an early stage in a bitch's breeding career and to screen for any genetic abnormalities. A thorough physical examination and accurate history guide the choice of which diagnostics tests are most useful. Ultrasound, culture, cytology, and biopsies (surgical and nonsurgical techniques) are discussed. Knowing which stage of the cycle to perform these diagnostics yields the most information and increases the chance of a successful outcome.

Evaluation of chlorhexidine hydrochloride treatment on endometrial health of normal mares.

Chlorhexidine gluconate solution is a potent antimicrobial and therefore could be used effectively for treatment of endometritis, but historically this substance has been implicated as irritating to mucous membranes, including the endometrium of the mare. The use of chlorhexidine hydrochloride suspension (Nolvasan Suspension, Zoetis, Florham Park, NJ, USA) was evaluated in the uterus of normal mares to determine if adverse effects on endometrial health were noted. Twelve healthy, adult light breed mares were included in this study. Procedures were approved by the Auburn University Institutional Animal Care and Use Committee. All mares were determined to be reproductively normal by evaluation of endometrial histopathology, cytology, and bacterial culture. Mares were randomly assigned to treatment or control groups (n = 6 per group). Each mare was treated during estrus with an intrauterine infusion of 1 g (28 mLs per tube; 35.7 mg/mL) of chlorhexidine hydrochloride suspension (treatment group) or an equal volume of lactated ringer's solution (control group) once daily for 3 consecutive days. Biopsy and cytology samples were taken 3, 7, and 14 days after completion of treatment. Cytology and biopsy samples were read by a board-certified pathologist (L.N.) blinded to treatments, and biopsy samples were graded using a standardized Kenney-Doig score. There was no difference with respect to biopsy grade, degree of endometrial fibrosis, or presence of cytologic inflammation comparing control and treatment groups (P = 0.55, 0.7, and 0.06, respectively), neither when accounting for sampling day. The suspension was visible within the uterine lumen when mares were examined with transrectal ultrasonography for up to 4 days after treatment. Treatment with chlorhexidine hydrochloride in this formulation and at this concentration does not appear to have a deleterious effect on short term endometrial health in mares.

Distribution and regulation of gonadotropin-releasing hormone, kisspeptin, RF-amide related peptide-3, and dynorphin in the bovine hypothalamus.

Recent work has led to the hypothesis that kisspeptin/neurokinin B/dynorphin (KNDy) neurons in the arcuate nucleus (ARC) play a key role in gonadotropin-releasing hormone (GnRH) pulse generation and gonadal steroid feedback, with kisspeptin driving GnRH release and neurokinin B and dynorphin acting as pulse start and stop signals, respectively. A separate cell group, expressing RFamide-related peptide-3 (RFRP-3) has been shown to be a primary inhibitor of GnRH release. Very little is known regarding these cell groups in the bovine. In this study, we examined the relative immunoreactivity of kisspeptin, dynorphin, and RFRP-3 and their possible connectivity to GnRH neurons in the hypothalami of periestrus and diestrus bovine. While GnRH and RFRP-3 immunoreactivity were unchanged, kisspeptin and dynorphin immunoreactivity levels varied in relation to plasma progesterone concentrations and estrous status. Animals with higher plasma progesterone concentrations in diestrus had lower kisspeptin and increased dynorphin immunoreactivity in the ARC. The percentage of GnRH cells with kisspeptin or RFRP-3 fibers in close apposition did not differ between estrous stages. However, the proportions of GnRH cells with kisspeptin or RFRP-3 contacts (∼49.8% and ∼31.3%, respectively) suggest direct communication between kisspeptin and RFRP-3 cells to GnRH cells in the bovine. The data produced in this work support roles for kisspeptin and dynorphin, within the KNDy neural network, in controlling GnRH release over the ovarian cycle and conveying progesterone-negative feedback onto GnRH neurons in the bovine.

Infection of an equine placenta with a novel mycobacterial species leading to abortion.

A 25-year-old pregnant American Quarter Horse mare presented with a 1-week history of progressively worsening vaginal discharge. Transrectal ultrasound revealed increased thickness of the combined uterus and placenta with evidence of chorioallantoic edema but no placental separation. A thickened amnion was visible on transabdominal ultrasound. Abortion occurred 2 days after presentation despite medical treatment. At necropsy, the chorioallantois had variable but diffuse thickening with focally extensive browning of the chorionic surface in the right horn and adjacent body. There were fluid-filled sacculations on the allantoic surface of the umbilical cord, allantoamnion, and chorioallantois associated with diffuse perivascular fluid microscopically. A nonbranching acid-fast bacterium identified as belonging to the genus Mycobacterium Runyon group IV was isolated from the chorioallantois and uterine fluid. Ziehl-Neelsen stain confirmed the presence of intracellular acid-fast bacilli in trophoblasts of the gravid horn and the cervical star area. The current case is unique in that the mycobacteria did not initiate a significant granulomatous inflammatory response in the chorion unless villar necrosis occurred. Sequence analysis of the 16S ribosomal RNA gene and the rpoß gene, encoding the ß subunit of RNA polymerase, indicated that the strain of mycobacteria isolated in this case belonged to a novel species of rapidly growing mycobacteria and not to an established species. Mycobacteria are an uncommon and sporadic cause of placentitis and abortion, but should be suspected in cases of chronic placentitis that are not restricted to the cervical star area.

Clinical approaches to infertility in the bitch.

When presented with the apparently infertile bitch, the practitioner must sort through a myriad of facts, historical events, and diagnostic tests to uncover the etiology of the problem. Many bitches that present for infertility are reproductively normal and are able to conceive with appropriate intervention and breeding management. An algorithmic approach is helpful in cases of infertility, where simple questions lead to the next appropriate step. Most bitches can be categorized as either cyclic or acyclic, and then further classified based on historical data and diagnostic testing. Each female has a unique set of circumstances that can affect her reproductive potential. By utilizing all available information and a logical approach, the clinician can narrow the list of differentials and reach a diagnosis more quickly.

Interaction of estrogen and progesterone on kisspeptin-10-stimulated luteinizing hormone and growth hormone in ovariectomized cows.

BACKGROUND/AIMS: Growth hormone (GH) is necessary for optimal reproductive efficiency and its secretion is influenced by sex steroids. This study was designed to determine whether kisspeptin-10 (Kp10) could stimulate GH and if gonadal steroids enhance the GH response to Kp10 in cows. METHODS AND RESULTS: Intravenous injection of Kp10 at 100 or 200 pmol/kg body weight with or without treatment with estradiol cypionate and/or progesterone increased luteinizing hormone (p < 0.01) plasma concentrations. Plasma concentrations of GH were increased following Kp10 in cows treated with estradiol cypionate and/or progesterone (p < 0.05) but not in cows treated with Kp10 without gonadal steroids. CONCLUSIONS: These data suggest that reproductive steroids enhance the sensitivity of the somatotropic axis to physiologically relevant doses of Kp10, and support the possibility that Kp10 is an integrator of luteinizing hormone and GH release.