Evidence for anti-inflammatory effects of firocoxib administered to mares with experimentally induced placentitis.

PROBLEM: Minimal evidence exists supporting therapeutic selections for equine placentitis. The goal of this study was to characterize the anti-inflammatory effects of firocoxib when administered to mares with placentitis. METHODS: Mares (gestation D270-300) were assigned to: INFECT (n = 6; placentitis, no treatment), FIRO (n = 6; placentitis, firocoxib, 0.1 mg/kg, PO, daily), and NORM (n = 6; no infection/treatment). Allantoic fluid (8 hours, 24 hours, birth) and amniotic fluid (birth) were collected from mares after infection. Concentrations of IL-1ß, IL-6, TNF-α, IL-10, PGF2α , and PGE2 in fluids were measured by ELISA. mRNA expression of IL-1ß, IL-6, TNF-α, IL-8, IL-10, matrix metalloproteinases (MMPs) -1, 3, and 9 in fetal membranes/fetuses was quantified using real-time PCR. RESULTS: Allantoic TNF-α concentrations were lowest in FIRO at 8 hours and 24 hours post-infection; IL-6 concentrations were lower in FIRO than NORM at 8 hours, lower in FIRO than INFECT at 24 hours post-inoculation, and lower in NORM than FIRO or INFECT at birth. Marginal mean allantoic IL-ß and IL-10 concentrations were lower in FIRO and NORM than INFECT. Amniotic fluid cytokines were lowest in NORM with all measurements in that group being below the limit of detection. Allantoic PGF2α concentrations were lower in FIRO and INFECT than NORM at 8 hours post-inoculation, and lower in FIRO than INFECT or NORM at 24 hours post-inoculation. Allantoic PGE2 concentrations were lower in FIRO than INFECT. Amniotic PGF2α and PGE2 concentrations were lower in NORM than INFECT. In fetal membranes, group differences with respect to IL-1ß, IL-6, IL-8, and MMP1 were dependent on tissue type. CONCLUSIONS: Data suggest a suppressive effect of firocoxib administration on cytokine and prostaglandin production in mares with placentitis.

Plasma metabolomic profiling of healthy pregnant mares and mares with experimentally induced placentitis.

BACKGROUND: Metabolomics may represent an avenue for diagnosis of equine ascending placentitis. OBJECTIVES: To characterise the plasma metabolomic profile in healthy mares and mares with induced ascending placentitis, with the goal of identifying metabolites with potential clinical value for early diagnosis of placentitis. STUDY DESIGN: Controlled in vivo experiment. METHODS: Placentitis was induced in 10 late-term pregnant pony mares via Streptococcal equi subsp. zooepidemicus inoculation in five mares between days 285 and 290 of gestation, while five mares served as healthy controls. Repeated ultrasound examinations and jugular venipuncture were performed to obtain combined thickness of the uterus and placenta (CTUP) and plasma for NMR spectroscopy. Mares with increased CTUP were diagnosed with placentitis and treated in accordance with published therapeutic recommendations. NMR metabolomic analysis was performed to identify and quantify plasma metabolites at each time point. Concentrations were compared using ANOVA with repeated-measures and PLS-DA analysis. RESULTS: Four hours post-inoculation, a significant increase was detected in the metabolites alanine, phenylalanine, histidine, pyruvate, citrate, glucose, creatine, glycolate, lactate and 3-hydroxyisobutyrate that returned to baseline by 12 hours. On day 4, a significant reduction in the metabolites alanine, phenylalanine, histidine, tyrosine, pyruvate, citrate, glycolate, lactate and dimethylsulfone was seen in infected mares compared with controls. MAIN LIMITATIONS: There were small numbers of mares within groups. In addition, this work compares healthy animals with animals treated with multimodal therapeutics following diagnosis of placentitis without an untreated cohort. CONCLUSIONS: Two phases of metabolite changes were noted after experimental infection: An immediate rise in metabolite concentration involved in energy, nitrogen, hydrogen and oxygen metabolism within 4 hours after inoculation that was followed by a decrease in metabolite concentrations involved in energy and nitrogen metabolism at 4 days, coinciding with ultrasonographic diagnosis of placentitis.

Metabolomic Profile of Allantoic and Amniotic Fluid in Late-term Gestational Mares Characterized by 1H-nuclear Magnetic Resonance Spectroscopy.

The amniotic and allantoic fluid compartments in the mare serve essential roles throughout pregnancy and parturition. Although the global metabolomic profile of amniotic fluid in women has been extensively characterized, current data for equine fetal fluids are limited. Therefore, the goal of this study was to characterize the global metabolomic profile of equine allantoic and amniotic fluid through nuclear magnetic resonance spectroscopy. Fetal fluids were collected between 270 and 295 days of gestation from 12 pregnancies through ultrasound-guided transabdominal puncture. A total of 24 samples (n = 10 allantoic fluid; n = 9 amniotic fluid; n = 5 admixed fluid) were analyzed by one-dimensional proton (1H) and two-dimensional (1H-13 C) nuclear magnetic resonance spectroscopy. Metabolites were integrated and compared between fluid types using a Kruskal-Wallis test at P < .05 significance. A total of 28 distinct metabolites were found in allantoic and admixed fluid, whereas 23 metabolites were identified in amniotic fluid. Allantoic fluid contained significant elevations (P < .05) in the metabolites betaine, creatine, creatinine, citrate, histidine, nitrophenol, tryptophan, π-methylhistidine, and unknown metabolite #1 compared with amniotic fluid, whereas amniotic fluid contained statistically increased concentrations of the metabolite lactate compared with allantoic fluid (P = .003).

Antimicrobial Activity of Ceftiofur and Penicillin With Gentamicin Against Escherichia coli and Streptococcus equi Subspecies zooepidemicus in an Ex Vivo Model of Equine Postpartum Uterine Disease.

The use of antimicrobials for the management of equine uterine disease is commonplace, with antibiotic selection generally based on empirical evidence or in vitro sensitivity results. However, the potential disconnect between these laboratory results and clinical efficacy in the mare raises concern for antibiotic failure and subsequent development of resistant organisms. In this work, we attempt to bridge this gap by using an ex vivo model of the equine postpartum uterus to quantitatively evaluate the antimicrobial activity of two commonly used antibiotic treatments in the mare (ceftiofur and penicillin with gentamicin). The activity of both of these treatments was evaluated in two different fluid environments (standard bacterial culture broth and equine postpartum uterine fluid) against clinical isolates of E. coli and S. zooepidemicus. Although treatment with ceftiofur was effective at reducing growth of S. zooepidemicus in equine postpartum uterine fluid, it did not reduce bacterial growth of E. coli. Treatment with procaine penicillin G with gentamicin achieved at least bacteriostatic activity against E. coli in both fluid types, and bactericidal activity against S. zooepidemicus in both fluid types. The intrauterine infusion of procaine penicillin G with gentamicin in cases of postpartum uterine disease caused by E. coli or S. zooepidemicus is supported by the results of this work.

Pharmacokinetics of Intrarectal Altrenogest in Horses.

Hospitalized pregnant mares being held nil per os (PO) because of medical or surgical events present a dilemma for pregnancy maintenance therapy, which commonly includes oral altrenogest. Rectal administration of medications is a recognized route for achieving systemic concentrations, but there are no data on the pharmacokinetics of rectal altrenogest administration in horses. The purpose of this study was to determine the pharmacokinetics of altrenogest following PO or per rectum (PR) administration in mares. Using a randomized two-way crossover study design, six horses received altrenogest (0.088 mg/kg; PO or PR q 24 hours for 5 days), with a 7-day washout period, and the concentrations of altrenogest were determined by an ultrahigh performance liquid chromatography with tandem mass spectrometry. Plasma concentrations persisted above presumed therapeutic concentrations for a mean of 36 hours (range 24-72 hours) and 5.5 hours (range 3-8 hours) for PO and PR administration, respectively. The calculated half-life (T ½) of PO administration (7.01 ± 3.13 hours) was correspondingly increased when compared to PR administration (2.82 ± 1.07 hours). Relative bioavailability of altrenogest following PR administration was only 5.47%. Altrenogest is rapidly absorbed following PR administration in the horse and reaches therapeutic concentrations, making this a viable method of treatment in NPO mares. The decreased bioavailability and shorter detection time suggest 0.088 mg/kg PR q 4-8 hours would be necessary to maintain therapeutic concentrations over a 24-hour period.

Sperm quality during extra-gonadal sperm reserve depletion in stallions.

To estimate when, during stallions' extra-gonadal reserves (EGR) depletion period, sperm quality would reach its highest quality, six light breed sexually rested stallions were collected daily for 7 days to deplete EGR. On collection days 1, 3, 5, and 7, sperm output, total (TM) and progressive (PM) motility, morphology, and plasma membrane (PLM) integrity were evaluated. Sperm output decreased as EGR depletion advanced, stabilizing on days 5-7. Sperm motility (TM and PM) and morphology were not different during EGR depletion. Plasma membrane integrity improved from day 1 to 3; however, no further improvement observed on days 5 and 7. Sperm of sexually rested stallions reach the highest quality on day 3 of the EGR depletion period.

Characteristics of Dogs with Biofilm-Forming Escherichia Coli Urinary Tract Infections.

BACKGROUND: Bacterial urinary tract infections (UTIs) are common in companion animals. Increasing awareness of biofilm-forming bacteria raises concern regarding the appropriate diagnosis, treatment, and prognosis of UTIs associated with these organisms. HYPOTHESIS/OBJECTIVES: To (1) describe the population of dogs with UTIs associated with biofilm-forming Escherichia coli and (2) determine whether or not clinical differences exist between dogs with biofilm-forming E. coli UTIs and dogs with nonbiofilm-forming E. coli UTIs. We hypothesized that there would be no difference in the population characteristics, but that biofilm-formation would be more prevalent in dogs with chronic, complicated, and asymptomatic UTIs. ANIMALS: Seventy-six client-owned dogs with E. coli UTIs, divided into 2 groups based on the biofilm-forming capability of stored bacterial isolates as assessed by the crystal violet assay. METHODS: Retrospective cross-sectional study. Medical records of the affected dogs were reviewed and their population and infection characteristics were compared. RESULTS: Most (52.6%) E. coli isolates were capable of forming biofilms. Biofilm-forming E. coli had a lower likelihood (P < .001) of multidrug resistance than did nonbiofilm-forming E. coli. No statistically significant differences were identified between the population or infection characteristics of the 2 groups of dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Escherichia coli isolated from canine urinary tracts are frequently capable of forming biofilms. Because no reliable clinical features allowed exclusion of biofilm formation, the potential for biofilm formation should be considered whenever E. coli UTI is diagnosed. The association of antibiotic resistance and biofilm potential may affect treatment of UTIs, but additional investigation is warranted.