Normal and abnormal response to sperm deposition in female dogs: A review and new hypotheses for endometritis.

In mammalian species there are significant physiological responses of the female reproductive tract to the deposition of sperm. These are particularly notable in species where sperm are deposited directly into the uterus, and function both to facilitate sperm transport to the sperm reservoir, and to eliminate introduced contaminants. In the bitch, sperm are deposited into the vagina and are rapidly transported through the open cervix. Sperm are then distributed around the uterus by uterine contractions such that transportation to the tip of the uterine horns occurs within 1 min of the start of mating. The main sperm reservoir appears to be the distal part of the utero-tubal junction which forms a pre-uterine tube reservoir. Sperm remain attached here by their heads to uterine epithelium and remain viable. In non-capacitating conditions sperm slowly detach from this site and this seems important to replenish the uterine tube reservoir, where sperm may re-attach to the epithelium. Post-ovulatory signals trigger capacitation changes and subsequent hyperactivated motility that is associated with detachment of sperm from both reservoirs; thus facilitating fertilization. After mating, a physiological post-mating uterine inflammatory response occurs, evidenced by an influx of polymorphonuclear neutrophils, increased uterine contractions, an increased uterine artery blood flow and a decrease of the resistance index indicating a short-duration vasodilation. Disturbance of this tightly regulated system has the potential to impact fertility by a failure of elimination of the introduced contaminants (such that a clinically-significant post-breeding endometritis ensues) but also by impairing sperm transport.

Horse owners' knowledge, and opinions on recognising colic in the horse.

BACKGROUND: Colic is the most common emergency problem in the horse. An owner's ability to recognise colic and seek assistance is a critical first step in determining case outcome. OBJECTIVES: The aim of this study was to assess horse owners' knowledge and opinions on recognising colic. STUDY DESIGN: Cross-sectional study. METHODS: An online questionnaire was distributed to horse owners with open and closed questions on their knowledge of normal clinical parameters in the horse, confidence and approach to recognising colic (including assessment through case scenarios), and their demographics. Descriptive and chi squared statistical analyses were performed. RESULTS: There were 1564 participants. Many respondents either did not know or provided incorrect estimates for their horse's normal clinical parameters: only 45% (n = 693/1540) gave correct normal values for heart rate, 45% (n = 694/1541) for respiratory rate and 67% (n = 1028/1534) for rectal temperature. Knowledge of normal values was statistically associated with participants' educational qualifications (P<0.01). Owners said if they suspected their horse had colic they would assess faecal output (76%; n = 1131/1486), gastrointestinal sounds (75%; n = 1113/1486), respiratory rate (65%; n = 967/1486) and heart rate (54%; n = 797/1486). There was a lack of consensus on whether to call a vet for behavioural signs of colic, unless the signs were severe or persistent. The majority of participants (61%) were confident that they could recognise most types of colic. In the case scenarios, 49% were confident deciding that a surgical case had colic, but 9% were confident deciding an impaction case had colic. MAIN LIMITATIONS: Most respondents were UK based; risk of self-selection bias for owners with previous experience of colic. CONCLUSIONS: There was marked variation in horse owners' recognition and responses to colic, and significant gaps in knowledge. This highlights the need for the development of accessible educational resources to support owners' decision-making.

Ultrasonographic-based predictive factors influencing successful return to racing after superficial digital flexor tendon injuries in flat racehorses: A retrospective cohort study in 469 Thoroughbred racehorses in Hong Kong.

BACKGROUND: Superficial digital flexor tendon (SDFT) injury is an important health and welfare concern in racehorses. It is generally diagnosed with ultrasonography, but predictive ultrasonographic features have not been reported. OBJECTIVES: To determine ultrasonographic features of forelimb SDFT injury at initial presentation in Thoroughbred racehorses that could predict a successful return to racing (completing ≥5 races). STUDY DESIGN: Retrospective cohort study. METHODS: Digitised ultrasonographic images of 469 horses with forelimb SDFT injuries from the Hong Kong Jockey Club (2003-2014) were evaluated, using a previously validated ultrasonographic scoring system. Six ultrasonographic parameters were evaluated (type and extent of the injury, location, echogenicity, cross-sectional area and longitudinal fibre pattern of the maximal injury zone [MIZ]), as well as horse signalment, retirement date and number of races before and after injury. Data were analysed by generalised linear regression with significance at P<0.05. RESULTS: Cases were divided into two groups: 1) For cases of SDFT tendonitis with core lesions, cross-sectional area at the MIZ was the most significant factor determining a successful return to racing (P = 0.03). If the lesion was <50% of the total cross-sectional area, horses had 29-35% probability of successfully racing again, but if it was ≥50% this decreased to 11-16%. 2) For cases of SDFT tendonitis without a core lesion, longitudinal fibre pattern at the MIZ best predicted a successful return to racing (P = 0.002); if the affected longitudinal fibre pattern was <75% of the total, horses had 49-99% probability of successfully return to racing, but if it was ≥75% this decreased to 14%. MAIN LIMITATIONS: Prognostic information may not be applicable to other breeds/disciplines. CONCLUSIONS: This is the first study to describe ultrasonographic features of forelimb SDFT injuries at initial presentation that were predictive of successful return to racing. The outcomes will assist with early, evidence-based decisions on prognosis in Thoroughbred racehorses.

The use of nutritional supplements in dressage and eventing horses.

The aim of the study was to determine which types of nutritional supplements were used in dressage and eventing horses, and the reasons that owners used supplements. An online questionnaire was distributed through British Eventing and Dressage websites, to collect data on demographics of owners and their horses, supplements used and their opinion on health and performance problems. Data were evaluated using descriptive analysis, Sign and Fisher's exact tests for quantitative data, and categorisation of qualitative data. In total, 599 responses met the inclusion criteria (441 dressage and 158 eventing horse owners). Participants had 26.4 (3-60) (mean (range)) years of riding experience, owned 1.2 (0-10) horses and used 2 (0-12) supplements in their highest performing horse. The main health and performance issues identified for dressage were 'energy/behaviour', 'lameness' and 'back and muscle problems'. The main issues for eventing were 'stamina and fitness levels',' lameness' and 'energy/behaviour'. The main reasons for using supplements in their highest performing horse were 'joints and mobility', and 'behaviour' for dressage, and 'electrolytes', and 'joints and mobility' for eventing. Lameness and behavioural problems were significant concerns within both disciplines. There was incongruence between owners' opinions of problems within their discipline and their reasons for using supplements.

Veterinary practitioners' selection of diagnostic tests for the primary evaluation of colic in the horse.

The aim of this study was to survey veterinary practitioners' selection of diagnostic tests for horses with clinical signs of abdominal pain. A questionnaire was distributed to veterinary surgeons involved in the primary evaluation of horses with abdominal pain, including the respondent's demographics, selection of diagnostic tests and factors affecting decision-making. Data analysis included descriptive analysis, categorisation of free text and simple univariable correlations to explore the relationships between independent variables and the relative self-estimated frequency that diagnostic tests were performed. A total of 228 responses were analysed. Participants worked in mixed practice (55.7 per cent), first opinion equine (22.8 per cent), first and second opinion equine (17.9 per cent) and referral practice (3.1 per cent). The majority (48.2 per cent, 105/218) were very confident managing a colic case (confidence level 4/5). The most frequently used diagnostic tests were 'response to analgesia' (87.2±24.0 per cent cases), rectal examination (75.9±21.2 per cent) and nasogastric intubation (43.8±27.6 per cent). Approach varied between practitioners, and for all diagnostic tests with frequency of use ranging from 0 to 100 per cent of cases. 'Risk to personal safety' was the most common reason for not using rectal examination. Practitioner's opinion of their confidence level in managing a colic case was associated with how frequently they used different diagnostic tests. There was marked variation in practitioners' approaches, highlighting the need for further evidence to support decision-making.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

REASONS FOR PERFORMING STUDY: Colic is the most common equine emergency problem, and one of the main causes of equid deaths. The horse owners' ability to recognise colic is a critical first step in determining case outcome. OBJECTIVES: To assess equine owners' knowledge and recognition of colic. STUDY DESIGN: Online questionnaire of horse owners. METHODS: An online survey was designed to evaluate owners' approach to colic in the horse. The survey included questions on owner demographics, their recognition of colic (including owner's opinions of their ability to recognise colic, their approach, and their recognition of colic using case vignettes), and their knowledge of normal ranges for clinical parameters. Descriptive and chi squared statistical analysis was performed. RESULTS: The survey was completed by 1061 UK respondents. Six per cent of owners thought they could recognise all types of colic, 61% said they could recognise most cases and 30% said they could recognise some but not all cases. Owners said they would assess faecal output (73% of respondents), gastrointestinal sounds (69%), respiratory rate (62%) and heart rate (50%) in horses with suspected colic. One fifth (22%) of owners would call a vet immediately without assessing any parameters. Many respondents either did not know, or provided incorrect estimates of normal values for clinical parameters: 30.4% were 'unsure' of the normal heart rate and 35.5% gave heart rate values which were outside reference ranges; only 24.5% gave appropriate values for normal respiratory rates and only 31% gave normal temperature values. There was no statistical significance between participants' age, educational qualifications, or their experience with horses and their knowledge of normal clinical parameters. CONCLUSIONS: Owners varied in their approach and ability to recognise colic, and many had significant gaps in their knowledge of normal parameters. Educational materials and/or training to assist owners could help address these issues. Ethical animal research: The study did not involve animal research. The study was reviewed and approved by the Ethics Committee, School of Veterinary Medicine and Science, University of Nottingham. The questionnaire was conducted in accordance with the 1998 Data Protection Act, and the British Educational Research Association's Revised Ethical Guidelines for Educational Research (2004). SOURCE OF FUNDING: Adelle Bowden's studentship is funded by the School of Veterinary Medicine and Science, University of Nottingham. Competing interests: None declared.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

REASONS FOR PERFORMING STUDY: Colic is a common reason for owners to seek veterinary treatment for their working equids in Morocco. There is no information available regarding cultural, religious or educational barriers to obtaining treatment or about the typical workload of these animals which may predispose them to colic. OBJECTIVES: To characterise the typical workload and feeding regimens of working equids in Morocco; to characterise the ability of owners to recognise the clinical signs and causes of colic; and to identify specific barriers to the veterinary treatment of colic. STUDY DESIGN: Questionnaire-based survey. METHODS: A standardised, structured questionnaire was administered, with the assistance of an Arabic speaking interpreter, to the owners of working equids presenting their animals to 2 centres run by SPANA (The Society for the Protection of Animals Abroad). Participation was voluntary and informed consent was obtained prior to the interview. RESULTS: All of the 102 participants that completed questionnaire were male. Ninety-eight owners used their animals for pulling carts, with 12% of animals working 7 days per week. 14% of animals were offered water by their owner once per day and 2% every other day. 25% of animals were loose and allowed free to feed unsupervised when not working. 29% of owners were not able to name any cause of colic and 25% did not recognise any clinical signs; only 12% associated colic with gastrointestinal pain. 83% of owners would not seek veterinary treatment due to financial constraints if free treatment at SPANA centres were not available. CONCLUSIONS: Colic remains a common problem amongst working equids in Morocco. Improved knowledge of management factors associated with colic and how to recognise abdominal pain may reduce the incidence of colic and improve prognosis. The findings presented can be used to inform and develop owner education programmes. Ethical animal research: The study was reviewed and approved by the Ethics Committee, School of Veterinary Medicine and Science, University of Nottingham. Informed consent for participation in the study was obtained from all owners and was delivered in the native language. No details identifying the owner were recorded. SOURCE OF FUNDING: None. Competing interests: None declared.

Water intake, faecal output and intestinal motility in horses moved from pasture to a stabled management regime with controlled exercise.

REASONS FOR PERFORMING STUDY: A change in management from pasture to stabling is a risk factor for equine colic. OBJECTIVES: To investigate the effect of a management change from pasture with no controlled exercise to stabling with light exercise on aspects of gastrointestinal function related to large colon impaction. The hypothesis was that drinking water intake, faecal output, faecal water content and large intestinal motility would be altered by a transition from a pastured to a stabled regime. STUDY DESIGN: Within-subject management intervention trial involving changes in feeding and exercise using noninvasive techniques. METHODS: Seven normal horses were evaluated in a within-subjects study design. Horses were monitored while at pasture 24 h/day, and for 14 days following a transition to a stabling regime with light controlled exercise. Drinking water intake, faecal output and faecal dry matter were measured. Motility of the caecum, sternal flexure and left colon (contractions/min) were measured twice daily by transcutaneous ultrasound. Mean values were pooled for the pastured regime and used as a reference for comparison with stabled data (Days 1-14 post stabling) for multilevel statistical analysis. RESULTS: Drinking water intake was significantly increased (mean ± s.d. pasture 2.4 ± 1.8 vs. stabled 6.4 ± 0.6 l/100 kg bwt/day), total faecal output was significantly decreased (pasture 4.62 ± 1.69 vs. stabled 1.81 ± 0.5 kg/100 kg bwt/day) and faecal dry matter content was significantly increased (pasture 18.7 ± 2.28 vs. stabled 27.2 ± 1.93% DM/day) on all days post stabling compared with measurements taken at pasture (P<0.05). Motility was significantly decreased in all regions of the large colon collectively on Day 2 post stabling (-0.76 contractions/min), and in the left colon only on Day 4 (-0.62 contractions/min; P<0.05). CONCLUSIONS: There were significant changes in large intestinal motility patterns and parameters relating to gastrointestinal water balance during a transition from pasture to stabled management, particularly during the first 5 days.

Incidence, causes and outcomes of lameness cases in a working military horse population: a field study.

REASONS FOR PERFORMING STUDY: Lameness is a common problem in the horse. Despite this, information on the incidence of lameness in horses in the UK is restricted to studies of lameness in performance horses, racehorses or referral hospital populations. OBJECTIVES: To determine the overall incidence and common causes of lameness in a working horse population and incidence, duration and outcome of conditions observed. STUDY DESIGN: Prospective questionnaire study. METHODS: Questionnaires were used to record lameness episodes in 294 horses in an equine military establishment. Information recorded included age, years of service, type of work, causal lesion, time taken to return to work and outcome. Lameness problems could be reported by any staff involved in the horses' care and were diagnosed by a veterinary surgeon or qualified farrier. Trends between lame and nonlame populations were compared using Chi-square analysis. Lameness diagnoses were grouped and analysed by disease category. RESULTS: Completed questionnaires for 273 horses were analysed. The mean monthly incidence of lameness was 2.1%, equivalent to an annual rate of 25.4 cases per 100 horses per annum, with a mean of 1.2 lameness episodes per horse in the lame population. Horse age and duration of service were not significantly different between lame and nonlame populations. The most common diagnoses were cellulitis (18.6%), skin wounds (16.3%) and foot/shoeing problems (11.6%) and 88% of cases had returned to previous levels of work by the conclusion of the study. CONCLUSIONS: This initial field study showed that lameness is a common occurrence in this working military horse population and the majority of cases make a full return to work. The most common causes of lameness identified in this study and outcomes of these conditions differ from existing literature. POTENTIAL RELEVANCE: This study highlights the need for further studies of lameness in the wider horse population.

Uterine fluid from bitches with mating-induced endometritis reduces the attachment of spermatozoa to the uterine epithelium.

Persistence of free fluid in the uterine lumen of bitches with endometrial hyperplasia appears to be diagnostic for mating-induced endometritis and is associated with reduced chances of pregnancy. This study investigated the possibility that reduced fertility might be associated with an effect of uterine fluid on sperm. Uterine lavage fluid was collected pre- and post-insemination from normal bitches without ultrasonographically-detectable luminal fluid (n=4), and previously non-pregnant bitches with endometrial hyperplasia and luminal fluid (n=4). Concentrations of polymorphonuclear neutrophils (PMNs) were measured and the effect of the fluid on the attachment of spermatozoa to the uterine epithelium was studied using medium (M) 199 as a control. To elucidate whether any effect was accounted for by the presence of PMNs, attachment was also measured in M199 with PMNs added at the concentration found in lavage fluid. Pre-insemination lavage fluid from both groups contained low concentrations of PMNs which increased post-insemination; the increase was larger for bitches with uterine fluid. Compared with M199 controls, lavage fluid reduced the attachment of spermatozoa; fluid from bitches with endometrial hyperplasia and uterine fluid had a greater effect than normal bitches, and post-insemination fluid had a greater effect than pre-insemination fluid. Spermatozoal attachment was reduced by a similar magnitude for M199 with added PMNs, although post-insemination fluid from bitches with endometrial hyperplasia reduced attachment more than M199 with added PMNs. Poor fertility in bitches with uterine luminal fluid might be partially associated with impaired attachment of spermatozoa to uterine epithelium, mediated principally, but not solely, by PMN influx into the uterine lumen.

Uterine artery blood flow characteristics assessed during oestrus and the early luteal phase of pregnant and non-pregnant bitches.

The aim of this study was to measure uterine artery blood velocity daily using Doppler ultrasonography in 10 young and 10 older clinically normal bitches throughout oestrus. Typical arterial waveforms identified in young bitches were characterised by a systolic peak and subsequent flow throughout diastole, whereas in older bitches, flow was sometimes absent in diastole. For 3 days immediately prior to ovulation, at the time of declining plasma oestrogen and increasing progesterone concentrations, resistance index (RI) increased, principally associated with decreased diastolic velocity; in some bitches there was absent late diastolic flow during this time. In older bitches, the waveform appearance was more variable, with absent late and early diastolic flow observed in some cases. Mean RI was higher throughout oestrus for older bitches compared with young bitches, although both groups had a similar 3-day duration increase before ovulation. Nine of the young bitches and five of the older bitches became pregnant; litter size was smaller for the older bitches. Non-pregnant bitches: (1) were significantly older; (2) had fewer waveforms with continuous diastolic flow 2 days before ovulation; (3) had lower end diastolic velocity, higher RI and fewer waveforms with continuous diastolic flow 2 days after ovulation, and (4) had lower plasma progesterone concentrations 5 days after ovulation. These are the first detailed observations of uterine artery blood velocity and waveform appearance throughout oestrus in bitches, and this is the first description of a link between impaired diastolic flow and reduced fertility. Assessment of uterine artery velocity could be useful to promote understanding of physiological mechanisms and could also become an important tool to assess potential infertility.

Prevalence and effect of uterine luminal free fluid on pregnancy and litter size in bitches.

Free fluid within the uterine lumen has been identified ultrasonographically as a transient finding in normal bitches in the period immediately after mating, and delayed clearance of the fluid has been documented in bitches with endometrial hyperplasia. This study used B-mode ultrasonography to investigate the prevalence of free fluid in the uterine lumen in normal bitches (n = 53) and bitches with endometrial hyperplasia (n = 10) on Days -7, 0, +5, and +14 in relation to estimated ovulation. For normal bitches without endometrial hyperplasia, 47 (86.6%) bitches become pregnant, whereas for bitches with endometrial hyperplasia, 3 (30%) become pregnant. In both the groups, the presence of uterine fluid on Days -7 and 0 was not associated with the probability of a bitch becoming pregnant, whereas the presence of uterine fluid on either Day +5 or +14 was significantly associated with a reduced likelihood of pregnancy. In pregnant bitches, uterine luminal fluid present on Day 0 was associated with a smaller litter size. This is the first study to establish the prevalence and effect of uterine luminal free fluid in bitches. We postulate that as the uterine luminal free fluid may be detected in normal bitches before mating and has no effect on the pregnancy rate or litter size in either group, this fluid is "physiological." However, it seems that the later in estrus the uterine fluid is present, the more likely it is to have an adverse effect on fertility. In some cases, this is manifest as a reduced litter size, while, importantly, the presence of fluid 5 to 14 days after ovulation is strongly associated with an absence of pregnancy, both in bitches with and without endometrial hyperplasia. We propose that ultrasonographic detection of uterine luminal free fluid after mating may be a useful prognostic indicator for pregnancy outcome, which may allow the targeting of treatments specifically to a population of animals that presumably develop mating-induced endometritis.

Epithelial surface changes and spermatozoa storage in the reproductive tract of the bitch.

Spermatozoa are known to bind to the epithelial cells lining the uterine tube in various species, but information in canids is conflicting and sparse. The first aim of this study was to measure the epithelial surface outline (ESO) of different regions of the canine uterine tube in the four stages of the oestrous cycle as an indicator of a changing potential reservoir for spermatozoa. The second aim was to identify the site of sperm storage in the bitch after natural mating. Reproductive tracts were collected from bitches undergoing routine ovariohysterectomy. Histological analysis showed that, when corrected for uterine tube size, the ESO of pro-oestrus (P<0.005) and oestrus (P<0.05) tubes were larger than anoestrus, but not metoestrus, tubes. The second study examined reproductive tracts from 12 Beagle bitches at 6, 12, 24 and 48h after mating. Light and electron microscopy revealed large numbers of spermatozoa in the proximal regions of the uterus and particularly the distal utero-tubal junction (UTJ), with few present in the proximal UTJ or uterine tubes. Spermatozoa were bound by their heads to microvilli on the epithelial surface of the uterine lumen and to ciliated cells in the distal UTJ. This is the first report to measure and document differences in potential epithelial attachment sites of the uterine tubes at different stages of the oestrous cycle and to provide compelling evidence that the main spermatozoal storage site in the reproductive tract of the bitch is the distal UTJ.

The bitch uterine response to semen deposition and its modification by male accessory gland secretions.

Little is known about the response of the bitch's reproductive tract to semen deposition. In this study, an influx of polymorphonuclear neutrophils (PMNs) into the uterus was detected after artificial insemination, but there was normal fertility. Doppler ultrasonography showed that insemination induced an increase in uterine artery blood velocity and a decrease in the resistance index of short duration, indicating vasodilation. Semen that was extended in fluid from the sperm rich fraction of the ejaculate (seminal plasma, SP), or third fraction of the ejaculate (prostatic fluid, PF), produced a similar magnitude of effect but of longer duration. It was hypothesised that vasodilation following insemination was largely induced by SP and PF which, together with PMN influx, was part of a normal uterine response. Physiological concentrations of PMNs in vitro reduced the ability of spermatozoa to attach to uterine epithelium, most likely as a result of spermatozoa becoming attached to PMNs. However, both SP and PF increased attachment of spermatozoa to the uterine epithelium by reducing sperm attachment to PMNs, and potentially by an additional mechanism that did not involve inhibition of sperm binding to PMNs. These are the first canine studies to document an apparent physiological response by the uterus to semen, associated with uterine artery vasodilation and PMN influx. Moreover, these investigations are the first to demonstrate that canine SF and PF are part of the mechanism for increasing uterine perfusion and that both fluids have a modulatory effect on PMN-induced inhibition of spermatozoal attachment to uterine epithelium, most likely mediated by reduced sperm attachment to PMNs.

Delayed uterine fluid clearance and reduced uterine perfusion in bitches with endometrial hyperplasia and clinical management with postmating antibiotic.

In many species a transient uterine inflammatory response follows mating and is proposed to remove excess spermatozoa, bacteria, and other contaminants from the uterus. Similar events have been documented in the bitch involving increased uterine contractions, polymorphonuclear neutrophil influx and uterine artery vasodilation. Some healthy bitches with endometrial hyperplasia have increased numbers of uterine luminal polymorphonuclear neutrophils after mating and reduced fertility; it is purported that this represents a presumed postmating endometritis. This study used B-mode and Doppler ultrasonography at the time of mating to measure uterine contractions, clearance of ejaculated fluid, and uterine artery velocity in normal bitches and those with endometrial hyperplasia. Mating resulted in an increase in the number of uterine contractions, although fewer mating-induced contractions were noted in bitches with endometrial hyperplasia. Interestingly, uterine fluid cleared significantly more slowly after mating from the bitches with endometrial hyperplasia than the normal bitches (P = 0.01). In a further study, Doppler ultrasonography showed that in normal bitches there was a significant increase in uterine artery blood velocity (P = 0.04) and a decrease in the resistance index after mating (P = 0.04), indicating vasodilation. In bitches with endometrial hyperplasia the baseline resistance index was significantly higher than normal bitches (P = 0.05), and furthermore, although there was a significant decrease in resistance index after mating, in the bitches with endometrial hyperplasia this was of a smaller magnitude that in normal bitches. These findings indicate lower baseline uterine perfusion, and a blunted vasodilation response to mating in bitches with endometrial hyperplasia. Short-duration postmating administration of systemic antibiotic increased pregnancy rates in bitches with endometrial hyperplasia (P < 0.01). Litter sizes in bitches with endometrial hyperplasia were lower than those of normal bitches both before and after treatment with postmating antibiotic (P = 0.04 and < 0.01, respectively). Mating-induced endometritis in bitches with endometrial hyperplasia appears to affect fertility by reducing the uterine vasodilatory response to mating and delaying clearance of uterine fluid as a result of decreased uterine contractions but the effect can be ameliorated in part by the postmating administration of antibiotic.

Perturbed sperm-epithelial interaction in bitches with mating-induced endometritis.

In several species there is a transient uterine inflammatory response after mating that is purported to clear excess and dead spermatozoa, bacteria and other contaminants from the uterus. In particular individuals this inflammatory response is substantial, resulting in an acute mating-induced endometritis, causing infertility. In this study, the influx of polymorphonuclear neutrophils (PMNs) into the uterine lumen of bitches was investigated after artificial insemination with fresh semen. In normal bitches, an influx of PMNs was detected, followed by high pregnancy rates and normal litter size, and may be a physiological inflammatory response. In bitches with endometrial hyperplasia, there was a larger influx of PMNs and pregnancy rates and litter size were reduced, although the effect was partly ameliorated by the post-mating administration of antibiotics. It is postulated that in bitches with endometrial hyperplasia, post-mating endometritis develops with the potential to affect reproduction adversely. In vitro studies demonstrated a reduced ability of spermatozoa to attach to the uterine epithelium of bitches with endometrial hyperplasia. Moreover, PMNs in the co-culture system inhibited spermatozoal attachment to normal and hyperplastic uterine epithelium, especially hyperplastic epithelium. It was concluded that decreased spermatozoal attachment to uterine epithelium mediates a reduction in fertility of bitches with endometrial hyperplasia. This is the first study to detail an apparent physiological uterine inflammatory response to spermatozoa and its perturbation in bitches with endometrial disease, and the first to recognise the clinical significance and potential aetiology of mating-induced endometritis.

Stimulation of mating-induced uterine contractions in the bitch and their modification and enhancement of fertility by prostatic fluid.

Little is known about the response of the bitch's reproductive tract to mating or of the role of male accessory gland secretions in the female. In this clinical study, the component stimuli causing mating-induced uterine contractions were investigated in 64 bitches. Basal uterine contractions were present during oestrus and a significant increase in the frequency of contractions was observed during natural mating. Neither teasing with a male nor stimulation of the vagina or cervix by vaginal or transcervical insemination (TCI) caused an increase in the frequency of uterine contractions. Increased contractions were however present after both vaginal and transcervical insemination when the vestibule was distended, and dorsal wall of the vaginal was manually stimulated. Interestingly, this increase in uterine contractions was partially ameliorated when prostatic fluid was used as a flushing component following transcervical insemination. Two further studies performed with 72 bitches of which 18 were each inseminated transcervically with fresh or frozen semen flushed into the uterus with either saline or prostatic fluid demonstrated that prostatic fluid significantly increased the pregnancy rate and litter size of both groups. There are important mechanisms regulating the transport and elimination of sperm from the bitch's reproductive tract. Whilst physical aspects of coitus are undoubtedly involved in initiating uterine contractions, prostatic fluid appears to have an important role in modulating uterine contractions and fertility.

Enhancing clinical learning in the workplace: a qualitative study.

Workplace learning (WPL) is seen as an essential component of clinical veterinary education by the veterinary profession. This study sought to understand this type of learning experience more deeply. This was done utilising observations of students on intramural rotations (IMR) and interviews with students and clinical staff. WPL was seen as an opportunity for students to apply knowledge and develop clinical and professional skills in what is generally regarded as a safe, authentic environment. Clinical staff had clear ideas of what they expected from students in terms of interest, engagement, professionalism, and active participation, where this was appropriate. In contrast, students often did not know what to expect and sometimes felt under-prepared when entering the workplace, particularly in a new species area. With the support of staff acting as mentors, students learned to identify gaps in their knowledge and skills, which could then be addressed during specific IMR work placements. Findings such as these illustrate both the complexities of WPL and the diversity of different workplace settings encountered by the students.

Investigation of the effect of pasture and stable management on large intestinal motility in the horse, measured using transcutaneous ultrasonography.

REASON FOR PERFORMING STUDY: Management regimes have been identified as risk factors for equine intestinal motility disorders. However, it is not known how management factors affect gastrointestinal motility. HYPOTHESIS: Large intestinal motility was similar in horses on a stabled and a pastured management regime. OBJECTIVE: To investigate the effect of 2 different management regimes on large intestinal motility assessed with ultrasonography. METHODS: A within-subjects crossover design was used to compare large intestinal motility between a stabled and a pastured regime in 16 working horses. Group A was managed under a standardised stabled regime throughout the study. Group B was maintained at pasture for the first monitoring phase and then transferred to the stabled regime for the second monitoring phase. Motility of the caecum, sternal flexure and aboral left ventral colon (contractions/min) was measured twice daily for 2 consecutive days using transcutaneous ultrasonography. Mean values for each management regime were pooled for analysis using multilevel statistical modelling. RESULTS: Significant variables identified by the model included: time of day, region of intestine, management regime, and combination of region of intestine and management regime. Motility assessed by ultrasound was significantly lower in stabled horses compared to pasture-kept horses. Intestinal motility for caecum was 1.7 ± 0.3 contractions/min (pastured = 2.0, stabled = 1.4), sternal flexure was 1.6 ± 0.2 contractions/min (mean (pastured = 1.7, stabled = 1.5), and left ventral colon was 0.8 ± 0.3 contractions/min (pastured = 1.0, stabled = 0.7). CONCLUSIONS: The null hypothesis was disproven. Large intestinal motility assessed by ultrasound was significantly reduced in stabled horses compared to pastured horses. This effect was most marked in the aboral left ventral colon. POTENTIAL RELEVANCE: This study has demonstrated a possible mechanism for the increased risk of large intestinal impactions in stabled horses.