Evaluation of the vaginal and urinary microbiota of healthy cycling bitches.

BACKGROUND: While the urogenital microbiota has recently been characterized in healthy male and female dogs, the influence of sex hormones on the urogenital microbiome of bitches is still unknown. A deeper understanding of the cyclic changes in urinary and vaginal microbiota would allow us to compare the bacterial populations in healthy dogs and assess the impact of the microbiome on various urogenital diseases. Therefore, the aim of this study was to characterize and compare the urogenital microbiota during different phases of the estrous cycle in healthy female dogs. DNA extraction, 16 S rDNA library preparation, sequencing and informatic analysis were performed to determine the vaginal and urinary microbiota in 10 healthy beagle dogs at each phase of the estrous cycle. RESULTS: There were no significant differences in alpha and beta diversity of the urinary microbiota across the different cycle phases. Similarly, alpha diversity, richness and evenness of vaginal bacterial populations were not significantly different across the cycle phases. However, there were significant differences in vaginal beta diversity between the different cycle phases, except for between anestrus and diestrus. CONCLUSION: This study strongly suggests that estrogen influences the abundance of the vaginal microbiota in healthy female dogs, but does not appear to affect the urinary microbiome. Furthermore, our data facilitate a deeper understanding of the native urinary and vaginal microbiota in healthy female dogs.

Validation of Calcein Violet as a New Marker of Semen Membrane Integrity in Domestic Animals.

Many fluorochromes routinely used in semen quality analysis emit in the green and red channels, limiting their possible combination for multiple parameter analysis. The use of fluorophores emitting in different light channels broadens the possibilities of combination to expand the range of simultaneously evaluated criteria. This is of great interest in cases of small ejaculated volumes, such as those naturally occurring in roosters, small dog breeds and drones (Apis mellifera). The purpose of this experiment is to establish Calcein Violet (CaV), a blue fluorochrome, as a marker of viability and acrosomal integrity in domestic animals in order to free the red and green channels. SYBR®14/Propidium Iodide (PI) was used as reference dye, heat-treated samples as negative controls, serial staining combination for validation and epifluorescence microscopy for observation. Dead spermatozoa marked in red with PI showed no blue fluorescence either from the head or the tail. Live spermatozoa showed a decreasing blue emission from head to tail when single stained with CaV. Unreacted acrosomes showed intense blue fluorescence irrespective of plasma membrane integrity. This needs to be further confirmed for species with small and difficult to observe heads. Establishment of CaV as a marker of membrane integrity by fluorescence microscopy is a decisive first step towards further technical development and use with flow cytometry.

Evolution of 17-ß-estradiol, estrone and estrone-sulfate concentrations in late pregnancy of different breeds of mares using Liquid Chromatography and Mass Spectrometry.

This study describes 17-ß-estradiol (E2), estrone (E1) and estrone-sulfate (E1S) concentrations between 4 and 11 months in healthy equine pregnancies of two different breeds using Liquid Chromatography coupled to Mass-Spectrometry (LC-MS). In 2 stud-farms including 15 Spanish PureBred (SPB) and 11 Showjumping (SJ) types mares, combined thickness of the uterus and the placenta (CTUP) was measured and blood was sampled monthly between 4 and 11 months of gestation. Concentrations of E2, E1 and E1S were assayed with LC-MS in mares with normal CTUP. Effects of breed, day of pregnancy and mare's parity and age on estrogens concentrations were investigated. Peak of E2 was observed at 5 months (median: 46.4 pg/mL; maximum: 201.5 pg/mL). A strong correlation was observed between E1 and E1S (p < 0.0001, r = 0.85). Peak of E1 (median: 571.0 pg/mL; maximum: 1641.9 pg/mL) and E1S (median: 573.6 ng/mL; maximum: 997.6 ng/mL) concentrations was observed at the 5th month and then E1S decreased quicker than E1 until the end of pregnancy. Higher E2 and E1 concentrations were observed in SJ than in SPB mares between the 6th and the 8th months. No difference between breeds was observed for E1S monthly evolution. Estrogen peak values were all observed at 5 months. Unlike recent LC-MS studies, E1S values observed here were in the same range than those previously established using immuno-assays. After the 6th month, E1S decreased quicker than E1. Effect of breed only observed on non-sulfonated estrogens should be further confirmed. These findings confirm that sulfonation activity of the allantochorion may be limited after the 6th month.

Imaging Findings in Dogs and Cats With Presumptive Sclerosing Encapsulating Peritonitis.

This retrospective case series describes imaging findings in seven dogs and two cats with a presumptive diagnosis of sclerosing encapsulating peritonitis (SEP) between 2014 and 2021. Peritoneal effusion was present in all animal patients. Sonographically, echogenic fluid with or without echogenic intraperitoneal septations, gathered or corrugated bowel loops, and abdominal lymphadenomegaly were suggesting an inflammatory process and the presence of adhesions. Gathering of the bowel with abdominal distension and/or signs of intestinal obstruction were major findings on radiographs. Abdominal fat stranding was an additional finding in animals undergoing a CT examination. Previous surgery, pregnancy, and the presence of a perforating foreign body were potential predisposing causes in 4/9 animals. Peritonitis was septic in 4/9 animals. As SEP is a rare condition but life threatening, this detailed description of imaging findings in a short case series can be useful for a presumptive diagnosis and surgical planning.