Allan Gunn

Assessment of uterine luminal pH in mares and the effect of dilute vinegar lavage on uterine luminal pH and endometrial health

Uterine luminal pH has been demonstrated to be a valid indicator of uterine health in species such as cattle and sheep. However, research regarding uterine luminal pH in equines is lacking. The objectives of this study were to assess uterine luminal pH in mares during the estrous cycle, and evaluate the effect of dilute vinegar lavage on both uterine luminal pH and endometrial health. The study was conducted using a randomized block design in which eight mares (four Thoroughbred and four Standardbred) were aged matched then randomly assigned to two groups. Endometrial biopsies were taken from each mare prior to trial commencement. The treatment group (n = 4; 1 Thoroughbred, 3 Standardbreds) received a uterine lavage of one liter dilute vinegar (20 mL of vinegar in 1 L saline) every second day during each estrus period throughout the trial. Control group mares did not receive a uterine lavage. Uterine luminal pH measurements were recorded in all mares in both groups for a period of up to 10 min immediately prior to lavage (0 h), one hour and 24 h post lavage (same time points in control group mares as if they had been treated). Diestrus uterine luminal pH measurements were recorded once between days 6-10 post-ovulation. Endometrial biopsies were repeated from all mares at trial completion. Mean uterine luminal pH ranged from pH 5.3 to 7.6 and was significantly lower during diestrus compared to estrus (P < 0.001). Regression analysis indicated that this variation in pH was best explained by estrous cycle day, with uterine luminal pH increasing by a mean of 0.03 units each day (P < 0.001) from 6 to 10 days post-ovulation through to ovulation. Uterine lavage with dilute vinegar did not significantly affect uterine luminal pH (P > 0.05). A scoring system to quantify the abundance of cell types in the endometrial biopsies showed that mares in the treatment group had a significant decrease in polymorphonuclear cell abundance between pre- and post-trial biopsies (P = 0.03). Mares in the treatment group also had a significant decrease in lymphocyte, plasma cell and eosinophil cell abundance (P = 0.05). Although dilute vinegar lavage was not associated with a significant change in uterine luminal pH, it was associated with a significant improvement in endometrial biopsy scores. Because the control group did not receive a uterine lavage, further research is required to determine if this significant improvement results from the addition of dilute vinegar, or the uterine lavage itself.

Oesophageal lumen pH in yearling horses and effects of management and administration of omeprazole.

BACKGROUND In human subjects, arytenoid chondritis can be caused by chemical trauma of mucosa attributable to gastro-oesophageal reflux. Although a similar process may be involved in the aetiopathogenesis of arytenoid chondritis in horses, the oesophageal lumen pH in this species is poorly understood. OBJECTIVES To determine if gastro-oesophageal reflux occurs in horses by characterising oesophageal lumen pH. STUDY DESIGN Blinded, randomised, placebo-controlled, crossover, experimental study. METHODS Luminal oesophageal pH in six yearling horses was recorded over four 24 h periods using an ambulatory pH recorder attached to a catheter with two electrodes (proximal and distal) inserted into the oesophagus. Recordings of pH were made during three management protocols. Initially, horses grazed in a paddock (Protocol A). Horses were then moved to stables to simulate sale preparation of Thoroughbred yearlings, and were given either omeprazole (Protocol B) or placebo paste (Protocol C) orally once per day. Protocol A was repeated for each horse (after a 13 day washout period) between Protocols B and C. Summary statistics described pH range and frequency of pH changes. Associations with predictor variables were investigated using linear mixed-effects models. Data are presented as the mean ± s.d. RESULTS Oesophageal lumen pH ranged from 4.90 to 9.70 (7.36 ± 0.27 and 7.18 ± 0.24 for the proximal and distal electrodes, respectively) and varied frequently (1.2 ± 0.9 changes/min and 0.8 ± 0.8 changes/min for the proximal and distal electrodes, respectively). Oesophageal lumen pH was associated with time since concentrate feeding, activity and time of day, but not with treatment of omeprazole. MAIN LIMITATIONS A small number of horses were used and measurement periods were limited. CONCLUSIONS Gastro-oesophageal reflux occurs in clinically normal yearling horses. Although omeprazole had no detectable effect, oesophageal lumen pH recorded during this study did not fall within the therapeutic range of omeprazole.

Chlamydiaceae: an update on nomenclature

THE Chlamydia genus belongs to the family Chlamydiaceae, in the order Chlamydiales, class Chlamydiia and the phylum Chlamydiae in the animal kingdom (Horn 2011). The genus Chlamydia and its species have undergone a number of significant name changes in recent years. Chlamydiales are an ancient phylogenetically isolated group of organisms that have undergone a reductive evolution, characterised by irreversible gene loss. Many Chlamydiales co-exist asymptomatically within specific hosts (Nunes and Gomes 2014), while a few are significant pathogens of humans and animals. The Chlamydiales have a complex biphasic life cycle that relies on a eukaryotic host cell for survival. The life cycle consists of metabolically inactive and infectious elementary bodies (EBs), and metabolically active vegetative reticulate bodies that undergo binary fission before reverting to EBs, which are expelled by the host cell (Bachmann and others 2014). The term ‘chlamydia’ may refer to …

Spontaneous lactogenesis and galactopoeisis in a virgin dairy heifer with evidence of a granulosa theca cell tumour

A 15-month-old, unmated heifer was presented at a routine reproductive herd health visit on 02 April 2012 near Honiton, Devon, UK with a distended udder that was leaking milk-like fluid from the teats. She had not been detected in oestrus, inseminated, or been in the presence of a bull. Clinical examination confirmed the heifer exhibited no signs of parturition, pregnancy, or of having been pregnant. There were no vulval or perineal signs consistent with recent parturition, or structural abnormalities of the external genitalia. Rectal palpation and ultrasonography of the reproductive tract revealed a uterus consistent with not having been gravid (approximately 2.5 cm maximum diameter), a large right ovary (approximately 6 cm in diameter) with heterogeneous ultrasonographic echogenicity including the presence of a few small (less than 5 mm) cyst-like structures. The left ovary was small (less than 2 cm diameter) and relatively uniformly echogenic, with no follicular or luteal activity detectable.