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Biomedical subjects

S W Ricketts

Publications and source records attributed to S W Ricketts.

At least 37 records · Page 2Linked to original sources
PubMed1987

Concentrations of uterine luminal prostaglandins in mares with acute and persistent endometritis.

Intrauterine infusion of 1 per cent oyster glycogen solution was used to induce acute endometritis in four genitally normal mares. Numbers of viable neutrophils recovered in uterine washings had increased by 1 h after infusion and remained elevated for at least 72 h. There was a significant correlation between numbers of viable neutrophils and total protein concentrations and between prostaglandin (PG)F and PGE2 concentrations in washings. There was also a significant relationship between concentrations of 15-keto-13, 14-dihydro PGF2 alpha in plasma and PGF in washings. Intrauterine concentrations of PGF were influenced by cycle stage and in turn the induced acute endometritis interfered with normal ovarian function. Mares with persistent endometritis had significantly higher concentrations of PGF and total protein and percentage of neutrophils and mononuclear cells in washings than normal mares. White blood cells from mares were capable of producing PGF and PGE2 in vitro.

Acute Disease↗
PubMed1987

Role of anaerobic bacteria in equine endometritis.

This study, performed over 3 breeding seasons, surveyed anaerobic and aerobic bacterial isolates from 362 clitoral and endometrial swabs and uterine washes from 263 Thoroughbred maiden, foaling, foal heat and barren mares, and from 113 urethral, urethral fossa, preputial and pre-ejaculatory fluid swabs from 29 Thoroughbred stallions. The significance of isolates was determined by their association with acute endometritis, as determined by concurrent endometrial smear results and by consideration of age and reproductive status before and after the survey. The results suggest that the horse uterus may harbour obligate anaerobes as surface commensals. These organisms normally inhabit the external genital surfaces of mares and stallions and are periodically introduced into the uterus at coitus or in association with genital pathology, e.g. pneumovagina or vagino/cervical injury. They may act as opportunist pathogens when there is epithelial damage, e.g. during the post-partum involutionary period. Synergism with aerobic bacteria may result in mixed infection and active endometritis. In the mare, the predominant uterine anaerobic species is Bacteroides fragilis. This species is predominantly penicillin- and aminoglycoside-resistant, a feature which is pertinent when intrauterine antimicrobial therapy for endometritis is considered. Detailed anaerobic diagnoses are unavoidably time consuming and as mixed infections are common, nitrofurantoin or metronidazole should be included in antibiotic mixtures. Failure to do this may account for some cases of aerobe-negative persistent endometritis.

Animals↗
PubMed1986

Changes in serum muscle enzyme levels associated with training schedules and stage of the oestrous cycle in Thoroughbred racehorses.

Blood samples were collected twice weekly over a nine month period from 24 Thoroughbred racehorses in training at Newmarket to study the effects of daily training schedules and stage of oestrous cycle on serum enzyme levels and clinical signs of equine exertional myopathy. The sampling period extended from November to July and was performed between 16:00 h and 18:00 h so as to be at least 6 h after exercise. Serum creatine kinase, aspartate aminotransferase and plasma progestogen concentrations were measured. All horses were subjected to a similar traditional training programme. The study demonstrated marked fluctuations in serum muscle enzyme concentrations which were more pronounced in two-year-old fillies than three-year-old fillies and colts. There was no correlation, however, with the stage of oestrous cycle. It was concluded that some degree of muscle cell damage, which results in a variable increase in serum creatine kinase levels, occurs in all horses following light exercise after a rest day. Traditional flat race training may not be ideal in this respect and it is suggested that, for horses with an observed tendency towards exertional myopathy, more consistent and longer periods of less strenuous exercise may be advantageous.

Animals↗
PubMed1984

Thirteen cases of botulism in horses fed big bale silage.

An outbreak of pharyngeal and limb paresis involving four horses and nine ponies in the south east of England is described. Nine of the animals died or were destroyed on humane grounds. The clinical features suggested a diagnosis of botulism and mouse innoculation tests confirmed the presence of type B toxin in the serum of one case. All animals were fed big bale silage. It is describe how, in plastic wrapped silage manufacture, conditions of fermentation may be inadequate to prevent the growth of Clostridium botulism. Examination of a sample of silage fed to the affected horses suggested that this was probably the source of the toxin.

Animal Feed↗
PubMed1983

Haematological response to racing and training exercise in Thoroughbred horses, with particular reference to the leucocyte response.

The haematological response to racing and to fast and slow training exercise was investigated in studies involving two populations of horses which differed widely in geographical location, climatic factors and management (Newmarket and Hong Kong). The well documented elevations in erythrocyte parameters were demonstrated and changing responses in leucocyte parameters, resulting in variations in the neutrophil to lymphocyte (N/L) ratio were described. It was shown that the immediate response to the anticipation or stress of exercise was a decrease in N/L ratio in association with an increase in lymphocyte numbers. The magnitude of the lymphocyte increases was similar in the two populations of horses producing a reversal of the N/L ratio (lymphocytes predominating) in the British but not the Hong Kong horses, owing to the higher resting ratio of the latter population. At 3 and 4 h after exercise, an increase in N/L ratio occurred in association with an increase in neutrophils and decrease in lymphocytes. All parameters had returned to resting level by 6 h following exercise. Those and the many other factors associated with alterations in equine N/L ratios are discussed in terms of the need for care when interpreting the results of haematological examinations.

Animals↗
PubMed1982

Results of concurrent bacteriological and cytological examinations of the endometrium of mares in routine stud farm practice 1978-1981.

The results of 4024 concurrent endometrial swab and smear tests taken from maiden, barren and post-parturient mares during early oestrus, before coitus demonstrated the practical value of these tests in routine stud farm practice. The use of cytological examinations provided a more direct diagnostic test for acute endometritis and this increased the accuracy of interpretation of the bacteriological findings.

Animals↗
PubMed1982

Use of ultrasound echography for early diagnosis of single and twin pregnancy in the mare.

In 1981 a trial was conducted on 6 Newmarket Thoroughbred stud farms into the use of real-time ultrasound echography (scanning) as an aid to the early diagnosis of pregnancy in the mare. The procedure was found to be practicable and interpretation of the findings was relatively straightforward. Pregnancy was positively diagnosed from as early as 14 days after ovulation and a number of twin pregnancies were recognized, some in which the conceptuses were situated in separate horns of the uterus but an almost equal number in which the conceptuses were together in the same horn. It was concluded that the technique of scanning will become an established part of stud-farm practice because it enables early identification of non-pregnancy and also of twin pregnancy before the critical stage of endometrial cup formation.

Animals↗