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.

Development and validation of a new standardised data collection tool to aid in the diagnosis of canine skin allergies

Canine atopic dermatitis (cAD) is a common hereditary clinical syndrome in domestic dogs with no definitive diagnostic tests, which causes marked morbidity and has a high economic impact internationally. We created a novel questionnaire for Labrador (LR) and Golden retriever (GR) owners to evaluate canine skin health with respect to clinical signs of cAD. 4,111 dogs had fully completed questionnaires (2,803 LR; 1,308 GR). 'Cases' (793) had a reported veterinary diagnosis of cAD, and 'controls' (1652) had no current or past clinical signs of cAD and were aged >3 years. Remaining dogs (1666) were initially categorised as 'Other'. Simulated annealing was used comparing 'Cases' and 'Others' to select a novel set of features able to classify a known case. Two feature sets are proposed, one for use on first evaluation and one for dogs with a history of skin problems. A sum for each list when applied to the whole population (including controls) was able to classify 'Cases' with a sensitivity of 89% to 94% and specificity of 71% to 69%, respectively, and identify potentially undiagnosed cases. Our findings demonstrate for the first time that owner questionnaire data can be reliably used to aid in the diagnostic process of cAD.

Incidence and impact of dog attacks on guide dogs in the UK: an update

Data on dog attacks on Guide Dogs' stock were reviewed to investigate the characteristics of the attacks. An average of 11.2 attacks occurred each month. Nearly all of the attacks occurred in public areas, 68.4 per cent of victim dogs were qualified guide dogs and 55.5 per cent of victim dogs were working in harness when they were attacked. Guide Dogs' stock were injured in 43.2 per cent of attacks and veterinary costs for attacks were estimated at £34,514.30. Over 40 per cent of qualified guide dogs' working ability was affected and >20 per cent of qualified guide dogs required some time off from working after a dog attack. Twenty dogs were permanently withdrawn from the Guide Dogs' programme as a result of dog attacks, 13 of which were qualified and working with guide dog owners at the time of the withdrawal; this resulted in a financial cost of >£600,000 to the charity. More importantly perhaps, temporary and permanent withdrawals have a significant impact upon the mobility and independence of guide dog owners and in many cases significantly impacted their emotional well-being.

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.

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.

Fertility and whelping complications in bitches following correction of vaginal abnormalities

The fertility and whelping complications of normal bitches and of bitches that had had surgery to correct a vaginal abnormality of varying severities were compared retrospectively. Reproductive performance and whelping statistics were compared between 37 bitches that had been diagnosed with a vaginal abnormality and 37 age- and breed-matched bitches with no history of vaginal abnormalities. There were no significant differences in reproductive performance between the affected and control bitches. When analysed by the severity of the abnormality, pregnancy rates were significantly lower for the group of bitches with the most severe abnormalities compared with the group of bitches that had mild vaginal abnormalities. Furthermore, the bitches that had severe abnormalities were significantly more likely to require a caesarean section than those with mild abnormalities.

Incidence and impact of dog attacks on guide dogs in the UK

In a retrospective survey, researchers identified 100 incidents of attacks on guide dogs by other dogs. These were reviewed in order to determine the number, severity and impact on the handler and dog, and the characteristics of the aggressors and victims. During the study period there were more than three attacks reported each month, with 61 per cent of the attacks being upon dogs that were in harness and working with an owner or trainer. The majority of the dogs that were attacked were male (62 per cent), and the breeds that were over-represented (relative to their prevalence in the general guide dog population) were the labrador and the golden retriever x flat-coated retriever crossbreed. Most of the attacks occurred in public places between 09.00 and 15.00 and the majority (61 per cent) of the attacking dogs were off the lead at the time of the attack. Thirty-eight per cent of the attacking dogs were of bull breeds, which were over-represented among attackers compared with the proportion of this breed type in the general dog population. Veterinary attention was sought after 41 per cent of the attacks, and in 19 per cent of instances there was injury to the handler or to a member of the public. The attacks were reported to have affected the working performance and behaviour of the victim dog in 45 per cent of the instances, and two dogs had to be subsequently withdrawn from working as guide dogs.

Follicular dynamics, ovulation and conception rates in bitches

Real-time ultrasound imaging was used in a clinical study to estimate the number of follicles of different sizes, ovulation and conception rates, and to study follicle dynamics following oestrus-induction of bitches. Follicles were identified during late anoestrus (between 100 and 60 days prior to the pre-ovulatory LH surge) and there appeared to be a shift in the population from small follicles (1-3 mm in diameter) to large follicles (>4 mm diameter) approximately 2 days prior to the LH surge. Corpora lutea could be reliably identified although the majority were cavitated. High ovulation rates (97-100%) and pregnant rates (86-100%) were detected, and although the conception rate was approximately 70% it varied between 8 and 92%. Within the narrow range of the clinical population studied there were trends relating age to reproduction performance. Oestrus induction with a gonadotrophin regime appeared to result in large numbers of small follicles that did not ovulate, whilst when using cabergoline the number of small and large follicels and the number of copora lutea were similar to those of control cycles.

Treatment of spontaneous pyometra in 22 bitches with a combination of cabergoline and cloprostenol

Twenty-two bitches with ultrasonographically diagnosed spontaneous pyometra were treated with a combination of 5 microg/kg cabergoline per day and 5 mug/kg cloprostenol every third day, and potentiated sulphonamide twice a day. Bitches with either open-cervix or closed-cervix pyometra showed a rapid clinical improvement, associated with a reduction in plasma progesterone concentration, increased vulval discharge and a reduction in the diameter of the uterus. The haematological profiles of 21 of the bitches returned to normal within six days of treatment, and their biochemical profiles returned to normal within nine days; 19 of the bitches were managed successfully by a 10-day period of treatment. Two bitches required a further three days of treatment, and in one bitch with a partial uterine torsion the treatment was not successful. Adverse effects of the treatment were limited to the 60 minutes immediately after the administration of prostaglandin, and included retching, vomiting, mild abdominal straining, diarrhoea and panting. The incidence of adverse effects was reduced after each successive dose of prostaglandin. Eleven of the 21 successfully treated bitches were mated at the next oestrus, and seven became pregnant; their litters were smaller than the published breed averages. In four of the bitches the pyometra recurred after the next oestrus.

Effects of coitus and the artificial insemination of different volumes of fresh semen on uterine contractions in mares

Uterine contractions may play an important role in the transportation of spermatozoa towards the site of fertilisation in the oviduct of mares. M-mode ultrasound was used to measure the number, amplitude and duration of uterine contractions in each uterine horn and the uterine body of oestrous mares for four minutes before and four minutes after either coitus, or the artificial insemination of either 80.0 ml of fresh semen or 10.0 ml of fresh semen. The direction of the uterine contractions in each uterine horn and the uterine body was measured before and after coitus. Coitus and the insemination of 80.0 ml semen significantly increased the total number, mean amplitude and mean duration of contractions in all parts of the uterus. The insemination of 10.0 ml of semen did not affect the total number or the mean duration of contractions in the uterine horns. Their mean amplitude was increased, but largely owing to the results from one mare; it also did not affect the contractions in the uterine body. There was no significant difference between the percentage of contractions moving in a cervicotubal or tubocervical direction after coitus in any part of the uterus examined.

Ultrasonographic characteristics of early pregnancy failure in bitches

Resorption of conceptuses was identified in 6 of 20 bitches examined daily from 15 to 35 d after the estimated pre-ovulatory LH surge. One or more conceptuses were resorbed in each bitch but there was continuation of the remaining pregnancy to term. This paper details the ultrasonographic embryological features of normal and resorbing conceptuses. Impending resorption may be predicted by detecting a delay in the time of development of a specific embryological feature or measuring a slow growth rate. Interestingly, there were greater number of conceptuses initially identified in bitches that subsequently resorbed than in those which did not.

Relationship between the fertile period and sperm transport in the bitch

Following ejaculation into the vagina, dog sperm remain functionally competent for many days, acquire the ability to fertilize, and are delivered to an appropriate site within the uterine tube synchronously with the appearance of fertile oocytes. The mechanisms involved in regulating this system are complex, and allow for sperm storage within the female reproductive tract. The aim of this paper is to review current knowledge of the transportation of sperm and their biology within the reproductive tract of the bitch.

Effect of teasing, mechanical stimulaton and the intrauterine infusion of saline on uterine contractions in mares

Uterine motility may have significance for the transportation of spermatozoa and the elimination of the ejaculate and inflammatory products after mares have been covered. The effect of some of the component stimuli of coitus on uterine contractions was investigated by using M-mode ultrasound. The number, amplitude and duration of the uterine contractions of each uterine horn and of the uterine body were measured in oestrous mares for four minutes before and four minutes after teasing by a stallion, mechanical stimulation of the vagina and cervix, the intrauterine infusion of 80 ml of sterile saline, the intrauterine infusion of 10 ml of sterile saline, the intrauterine infusion of 150 ml of sterile saline, and the transcervical passage of a uterine catheter. Teasing by a stallion did not affect the total number, mean amplitude or mean duration of the uterine contractions. Mechanical stimulation of the vagina and cervix increased the total number of uterine contractions, but did not affect the amplitude or duration of the contractions. The intrauterine infusion of 80 ml of sterile saline resulted in an increase in the total number of contractions and a significant increase in the mean amplitude and the mean duration of the contractions in the uterine horns but not the uterine body. The intrauterine infusion of 10 ml of sterile saline caused a significant decrease in the number of uterine contractions in the uterine horns, but had no effect on the contractions of the uterine body. The infusion of 150 ml of sterile saline reduced the number of contractions in the uterine horns but not the uterine body, and did not affect the mean amplitude and mean duration of the contractions. The transcervical insertion of a catheter reduced the number of contractions in the uterine horns, but did not affect the amplitude or duration of the uterine contractions.

Influence of Griseofulvin treatment on semen quality in the dog

Griseofulvin is used to treat dermatomycosis in many species and causes oligospermia in supra-pharmacological doses. The aim of the present study was to evaluate the effect of Griseofulvin administered at therapeutic doses upon semen quality in dogs. Four dogs were treated with Griseofulvin (25 mg/kg per day) for 30 days. Semen collections and analyses were performed before, during and for 100 days after treatment for the Griseofulvin group and 10 untreated control dogs. Semen analyses included mean percentage of forward progressively motile sperm, total sperm output, normal live sperm and normal dead sperm. There was no significant difference between control and treated dogs for each of the semen quality parameters. Therapeutic dosage of Griseofulvin had no deleterious effect upon semen quality in dogs, although this does not preclude potential embryotoxic and teratogenic effects.

Cardiovascular effects of romifidine in the standing horse

The cardiovascular effects of romifidine, an alpha-2 adrenoreceptor agonist, were investigated in six horses using two doses (80 and 120 microg kg(-1)) in a cross-over study design. Cardiac index and mixed venous oxygenation were significantly decreased at 15 and 30 minutes after both doses of romifidine. Systemic vascular resistance was significantly increased with romifidine (120 microg kg(-1)). Arterial blood pressure increased initially and then gradually decreased; the doses of decrease was significant at 90 and 120 minutes with romifidine 80 and 120 microg kg(-1). There were minimal differences between the two doses of romifidine, and both should be used with care especially in horses with cardiovascular compromise, or when used in combination with other cardiovascular depressant drugs.

The effects of endometrial scarification on uterine steroid receptors, bacterial flora and histological structure in the bitch

Following laparotomy, the endometrium of six nulliparous Beagle bitches was scarified at the base of one uterine horn during early metoestrus, when the peripheral plasma P(4) concentration was >10 ng/ml; intrauterine swabs were taken at the same time for bacteriological culture. Twenty-one days later, a bilateral ovariohysterectomy was performed and segments of the scarified and non-scarified parts of the tubular genital tract removed; at the same time, swabs were taken from the uterine lumen. Tissue samples were collected and examined for histopathological structure, and the presence of nuclear oestrogen (ER) and progesterone (PR) receptors using an immunocytochemical method. The immunoreactivity was scored semiquantitatively, incorporating both the intensity and distribution of specific staining of the receptors using a simplified histoscore (H-score). All uterine swabs were sterile, and in three of the six bitches there were noticeable changes with distension of the uterine lumen with secretions and debris and distension of the endometrial gland ducts of the scarified uterine segment. There were no statistically significant differences in the H-scores of ER or PR between scarified and non-scarified segments, except for PR H-scores in the glandular epithelium where the values for the scarified were significantly higher than for the non-scarified endometrium (mean+/-S.E.M. is 129.9+/-22.8 versus 59.5+/-12.6; P<0.05). Thus, trauma can modify the structure of the endometrium and the characteristics of the PR. Whether changes in PR expression are involved in the pathogenesis of CEH/pyometra in the bitch could not be ascertained from this study.