The most useful diagnostic methods in the initial evaluation of horses with colic assess the morphological and functional status of the gastrointestinal tract and cardiovascular status. This evaluation is best achieved using a combination of clinical and laboratory data. Blood lactate concentration (BL) is one of these variables. BL rises mainly due to poor tissue perfusion and anaerobic glycolysis associated with shock, providing an indicator of both the severity of disease and its prognosis. A hand-held lactate meter, Accusport, provides a rapid (60 seconds), inexpensive dry-chemical-based determination of BL. This trial evaluated the Accusport's ability to provide BL data as an adjunct to the initial clinical evaluation of horses with colic. The accuracy of the Accusport was tested by evaluation of its interchangeability with the benchmark enzymatic kit evaluation of BL in a trial using data collected firstly from 10 clinically normal control horses and subsequently from 48 horses presented with signs of colic. The BL values were recorded together with the clinical variables of heart rate (HR), capillary refill time (CRT), haematocrit (Hct), and pain character and severity on the initial assessment of the colic horses. Information regarding choice of therapeutic management (medical or surgical) and eventual case outcome (full recovery or died/euthanased) was recorded. The Accusport was found to be interchangeable with the enzymatic kit for recording BL values in colic horses with BL <10 mmol/ , which is within the BL range associated with survival. The interchangeability of an additional, laboratory-based wet chemical assay for BL, the Stat 7 was simultaneously evaluated for the colic and control horses. The Stat 7 was found to be interchangeable with the enzymatic kit for BL determination of colic horses. No linear associations between BL values with HR, CRT, Hct or pain assessment were observed. No relationship with either selection of therapeutic method or eventual case outcome was observed. All horses with BL >8 mmol/ died or were euthanased

Circulating anti-Müllerian hormone concentration (AMH) is positively correlated to the number of small growing follicles in the mare and may reflect ovarian function. Dynamics of AMH during immunocontraception have not previously been investigated. This study aimed to compare serum AMH in mares following treatment with native porcine zona pellucida (pZP), recombinant pZP3 and pZP4 (reZP) or gonadotrophin releasing hormone (GnRH) vaccines, and saline-treated controls. Stored sera collected during two previous studies examining ovarian activity in mares during zona pellucida (ZP) or GnRH immunocontraception were analysed for serum AMH. Data were compared among treatment groups using mixed-effects linear regression and one-way ANOVA with post hoc testing. Correlations between AMH and previously reported clinical variables were estimated using Spearman's rho. Mares immunized against GnRH showed variable but detectable AMH throughout successive breeding and non-breeding seasons that were not significantly different to unvaccinated control mares. Mares treated with pZP demonstrated marked, reversible suppression of AMH. Mares immunized using reZP showed an intermediate effect. In the ZP study, AMH was positively correlated to serum progesterone concentrations, mean ovarian volumes and antral follicle counts, whereas no correlations between AMH and serum progesterone concentrations, mean ovarian volumes, or the presence of one or more follicles ≥20 mm in diameter were detected in the GnRH study. In conclusion, marked suppression of AMH during pZP immunocontraception, but not during GnRH immunocontraception, suggested enhanced suppression of ovarian follicular development and, or follicular function during pZP immunocontraception. Serum AMH concentrations may provide a novel tool for the assessment of ovarian function during ZP-based immunocontraception.

ContentsTwo experiments were conducted in order to determine the clinical effects of intracervical application of prostaglandin E2 (PGE2) in mares. In Experiment 1, PGE2 or placebo tablets were introduced into the cervical canal of &oestrous mares. PGE2 induced SiBtllficant cervical softening and oedema within 30-90 min after application. Uterine tone increased significantly within a few min after PGE2 treatment and remained elevated for 60-90 min. PGE2 treatment had no effect on plasma progesterone concentrations. In Experiment 2, 19 mares were each subjected to one of 3 treatments: Group A (n=5) received 10 IU oxytocin intravenously on the first day after day 325 of gestation when clinical criteria of "readiness for birth" had been satisfied. Gestational age was 328-349 days. Mares in Group B (n=6) and Group C (n=S) were treated on the first convenient day after day 325 of gestation, but before their cervices had started to &late. Group B mares received 4 intracervical applications of PGE2 at 30 min intervals. Group C mares 'were given 10 IU oxytocin intravenously, 30 min after the second PGE2 application. Mares of Groups B and C were treated between days 327 and 338 of gestation. PGE2 treatment alone failed to consistently induce parturition and mares foaled between 14 h and 8 days after treatment. Complete cervical dilation was, however, induced in all PGE2 treated mares and was maintained until parturition. Group C mares (PGE2 followed by oxytocin) foaled 16-1 15 min after oxytocin treatment which was not different from Group A. Premature placental separation occurred in 1 of 5 mares in Group A and in 3 of 8 mares in Group C. All 5 foals in Group A were healthy and survived. Two of 6 and 3 of 8 foals in Groups B and C, respectively, developed neonatal dlsease and died between 1 and 26 days after birth. Although PGE2 induced rapid and complete cervical dilatation in near-term pregnant mares, it failed to induce parturition and when used in combination with oxytocin, foal health and survival were poor. It is concluded that PGE2 will be of little value as an adjunct to routine equine partus induction, because foal survival will be poor if inductions are performed at a stage when the mare's cervix is not adequately relaxed for induction of parturition using oxytocin alone. U.S