bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidemiological approach to the control of horse strongyles
Authors: HERD R. P. , WILLARDSON K. L. , GABEL A. A.
Published: April 2010

An investigation of the spring rise in strongyle egg output of grazing horses on two commercial horse farms in northern USA in 1981 and 1982 revealed two distinct spring and summer rises in faecal egg counts, with peaks in May and August/September. There was a marked rise in the concentration of infective larvae on pasture two to four weeks after the peaks in egg output, so that grazing horses were at serious risk from June onwards and pasture larval counts on one farm did not fall to low levels until June of the following year. The spring and summer rises in faecal egg counts appeared to be seasonal in nature, to be derived largely from worms developing from previously ingested larvae, rather than from newly ingested larvae, and to be unrelated to the date of foaling. An epidemiological approach to strongyle control based on prophylactic treatments in the spring successfully eliminated the spring rise in egg output but was inadequate to control the summer rise or subsequent escalation of pasture infectivity in September. It was, nevertheless, superior to a conventional treatment programme at eight week intervals, using the same drug, pyrantel pamoate. Prophylactic spring/summer treatments proved to be much more effective. Both pyrantel pamoate at four week intervals and ivermectin at eight week intervals kept faecal egg counts at low levels during spring and summer. As few as two ivermectin treatments (11 May, 6 July) resulted in a sixfold reduction in pasture larval counts on 9 November and 3 January for the treated group (8872, 8416 stage three larvae [L3]/kg) compared to the control group (52,824, 50,984 L3/kg). This strategy had far reaching prophylactic effects in preventing the late season rise in pasture infectivity and ensuring a low level of residual pasture infectivity at the start of the next grazing season.
Prevalence and epidemiology of the major gastrointestinal parasites of horses in Perth, Western Australia
Authors: DUNSMORE J. D. , SUE LINDSAY P. JUE
Published: April 2010

A survey was conducted on the prevalence of the major gastrointestinal parasites in 140 horses necropsied in Perth, Western Australia, during 1979 to 1982. Adult Strongylus vulgaris were found in 22.5 per cent of horses and verminous arteritis in 62.9 per cent. The peak worm prevalence was in November to January (summer). S edentatus had a similar prevalence and seasonality but S equinus was not found in this survey. Draschia megastoma and Habronema muscae were found in 66.2 per cent and 35.3 per cent of horses respectively. Infection is probably acquired in summer when 8 per cent of the Musca domestica in the vicinity of the stables carried third stage spiruroid larvae.

Gasterophilus intestinalis and G nasalis occurred in 36.4 per cent and 22.1 per cent of the horses respectively and 52.1 per cent of horses were infected with one or both species. The peak prevalence of G intestinalis larvae occurred in December with a trough in February‐April; the peak prevalence of G nasalis was in May with a trough in November‐December. Parascaris equorum was found in 9.9 per cent of the horses and in 21.3 per cent of those less than three years old. Anoplocephala perfoliata was found in 4.9 per cent of the horses and most of these were in older horses.
The ‘Turner’ circle absorber: An anaesthetic breathing system for the horse
Authors: BROWNLOW M. A. , TURNER D. M. , HUTCHINS D. R.
Published: April 2010

An inhalation anaesthetic apparatus for the horse is described and the physiological concepts pertaining to its design presented. The internal diameter of all breathing components is 6.2 cm with no change in cross sectional area throughout the circle system. The soda lime capacity is 25 litres (approximately 20 kg). In the horse, which is apparently predisposed to alveolar hypoventilation during inhalation anaesthesia, it is apparent that adequate anaesthetic apparatus design should be directed towards minimising resistance and dead space and providing maximal and efficient carbon dioxide elimination.
Genital injuries from mating in the mare
Authors: BLUE M. G.
Published: April 2010

Minor accidents during natural mating are common occurrences during the breeding of horses. Mares may suffer from a variety of genital injuries including vulval separations, vaginal lacerations and, less commonly, vaginal rupture. Possible sequelae to, and management of, these injuries are described, with additional mention of false entry by the stallion and persistent hymen in maiden mares. Vaginal rupture during natural mating can lead to death of the mare. The implications for litigation involving veterinary surgeons and horse breeders are discussed.
Effects of a submaximal treadmill training programme on histochemical properties, enzyme activities and glycogen utilisation of skeletal muscle in the horse
Authors: HODGSON D. R. , ROSE R. J. , DiMAURO J. , ALLEN J. R.
Published: April 2010

The effects of training on skeletal muscle composition were studied in four Standardbred geldings given a seven week submaximal treadmill training programme. Before the start of training, muscle biopsies were collected from the left middle gluteal muscle for the determination of muscle fibre types, oxidative capacity and capillary numbers using histochemical techniques. The concentrations of citrate synthase, 3‐hydroxyacyl‐CoA dehydrogenase (HAD), lactate dehydrogenase and total muscle glycogen were measured using fluorometric methods. Muscle biopsy samples were repeated after one, three, five and seven weeks of training and the same measurements performed.

No significant changes were found in muscle fibre types or capillary numbers as a result of training, although there was an increase in the oxidative capacity of the Type IIB fibres after seven weeks training. After seven weeks of training there were also increases in the concentrations of citrate synthase and HAD and a decrease in lactate dehydrogenase. Before commencement of training the horses underwent a standardised submaximal exercise test and muscle glycogen concentrations were measured before and immediately after the exercise. This procedure was repeated after one, three, five and seven weeks of training. A progressive decrease in the rate of glycogen utilisation occurred throughout the period of training, which by seven weeks was 36 per cent lower than that before training.
Activities of key enzymes of aerobic and anaerobic metabolism in middle gluteal muscle from trained and untrained horses
Authors: CUTMORE C. M. M. , SNOW D. H. , NEWSHOLME E. A.
Published: April 2010

The effect of physical training on the in vitro activities of key enzymes that provide quantitative information on the maximum capacities of anaerobic and aerobic metabolism has been investigated in the gluteal muscle of the horse. Training had no effect on the activities of 6‐phosphofructokinase or creatine kinase, suggesting that there was no effect on the capacity of anaerobic metabolism in this muscle. However, the activities of hexokinase and citrate synthase were increased, indicating that training increased the capacity of aerobic metabolism. For comparative purposes, muscle fibre composition and enzyme activities were also determined in a group of foals and a group of broodmares.
Comparison of echocardiographic and autopsy measurements of cardiac dimensions in the horse
Authors: O'CALLAGHAN M. W.
Published: April 2010

This study was initiated to determine the accuracy of M‐mode echocardiography in measuring left ventricular dimensions and estimating heart weights in horses. Left ventricular free wall and interventricular septal thickness and left ventricular external and internal diameters were measured and heart weights estimated from the echocardiograms of 47 horses. Autopsy measurements of the same parameters were then recorded. Statistical comparison of the data demonstrated: (1) Systolic measurements of wall thickness more closely resembled the heart in death than the diastolic measurements; (2) good correlations existed between parameters measured echocardiographically and at autopsy, especially wall thicknesses and left ventricular external diameter (maximum r = 0.82); (3) heart weight was readily predicted from echocardiographic wall thickness regressions (maximum R‐squared = 68 per cent). M‐mode echocardiography demonstrated the potential for direct and accurate measurements of cardiac mass and some ventricular dimensions in the horse. The data suggested that intense rigor and exsanguination may render the autopsied heart unsatisfactory for comparative measurements when assessing techniques such as echocardiography.
Incorporation of L‐75Se‐cystine in tissue fragments from the matrix of the hoof and the claw — A tool for studying the pathogenesis of laminitis?
Authors: EKFALCK A. , FUNKQUIST B. , JONES B. , OBEL N.
Published: April 2010

An in vitro method has been designed and used to study the incorporation of 75Se‐cystine into matrix fragments from hooves and claws of healthy horses and cattle. Tissue fragments from the zone of keratinisation were incubated with L‐75Se‐cystine in a tissue culture medium for 4 to 6 h, during which time there was continuous incorporation of the labelled selenocystine. The incorporation was greatly decreased by adding L‐cystine to the incubation mixture. It is concluded that the incorporation of 75Se‐cystine depends on the presence of a specific receptor for cystine in the tissue fragments studied. The possible application of the method to studies of the pathogenesis of laminitis is discussed.
An experimental study of the healing process of equine chondral and osteochondral defects
Authors: KOLD S. E. , HICKMAN J. , MELSEN F.
Published: April 2010

Four full thickness cartilage defects, two linear and two elliptical, and four subchondral cavity defects were created at the point of weightbearing of the medial femoral condyle in four experimental ponies. This study showed that subchondral bone cysts can develop following full thickness (cartilage only) linear cartilage defects at a weightbearing location. Subchondral bone cysts did not develop following the removal of an elliptical piece of cartilage, exposing the subchondral bone. Primary subchondral defects created in communication with the joint cavity did not heal by replacement with bone over a six‐month period. Fibrous and cartilaginous repair occurred which appeared to be unrelated to the size or depth of the subchondral defect. Irrespective of the size of the defects, the surrounding bone showed marked woven bone formation with remodelling of existing and newly formed bone. The resulting osteosclerosis indicated a positive balance and a natural limitation of cavity expansion. The positive balance affected only the surrounding bone and did not lead to re‐establishment of the bone within the cavity during the period studied.
Diagnostic techniques in the investigation of shoulder lameness
Authors: Dyson Sue
Published: April 2010

Methods of investigating horses with suspected shoulder lameness are described and discussed. The gait of shoulder lameness is characterised and compared with that of lower forelimb lameness. If lameness is slight, differentiation may be difficult, but if moderate, upper forelimb lameness usually results in shortening of the cranial phase of the stride and a low limb flight. Clinically, it may not be possible to differentiate between shoulder and elbow lameness without intra‐articular anaesthesia. Practical aspects of intra‐articular anaesthesia of the shoulder joint are reviewed. Synovial fluid must be retrieved to ensure that the needle is intra‐articular. Up to 60 mins may elapse after injection of local anaesthetic before significant improvement occurs. Lameness is often improved rather than eliminated. A technique for standing radiography of the shoulder is described and the limitations of assessing a joint only by lateral projections are highlighted. There may be difficulties in positioning weanling foals and yearlings, resulting in superimposition of the shoulder joint, cervical and thoracic vertebra and ribs. It is concluded that a combination of a thorough clinical examination, faradism, local anaesthesia, synovial fluid analysis and radiography usually enables an accurate diagnosis to be reached.
Paroxysmal atrial fibrillation in racehorses
Authors: HOLMES J. R. , HENIGAN M. , WILLIAMS R. B. , WITHERINGTON D. H.
Published: April 2010

The paper describes five cases of atrial fibrillation detected after racing. In four of them, the arrhythmia disappeared spontaneously within 24 h and they were regarded as paroxysmal in type. In the fifth case, which won its race, the arrhythmia persisted for at least 45 h after racing. It was therefore regarded as an example of persistent atrial fibrillation. It was then treated with quinidine sulphate which restored sinus rhythm. It would seem that paroxysmal atrial fibrillation may be a cause of sudden decrease in racing performance.
Surgical arthrodesis for the treatment of osteoarthrosis of the proximal intertarsal, distal intertarsal and tarsometatarsal joints in 30 horses: A comparison of four different techniques
Authors: WYN‐JONES G. , MAY S. A.
Published: April 2010

Over a period of seven years, 30 horses were treated by surgical arthrodesis for lameness resulting from osteoarthrosis of the proximal intertarsal, distal intertarsal and tarsometatarsal joints (bone and occult spavin). Twenty‐five horses were affected in one hock only and five were affected bilaterally. Four different techniques for achieving arthrodesis were used. Fourteen out of 18 horses (78 per cent) with involvement of the distal intertarsal and tarsometatarsal joints only and six out of 11 horses (55 per cent) in which the proximal intertarsal joint was also involved became sound following surgery. The status of one other horse, with involvement of the proximal intertarsal joint, is not known.
Glucose tolerance and insulin sensitivity in ponies and Standardbred horses
Authors: JEFFCOTT L. B. , FIELD J. R. , McLEAN J. G. , O'DEA KERIN
Published: April 2010

The existence of an innate insulin insensitivity in ponies was investigated and compared with the situation in larger breeds of horse. Ponies that were fat or had previously suffered laminitis were found to be far more intolerant to oral glucose loading (1 g/kg bodyweight [bwt]) than normal ponies or Standardbreds. These ponies also exhibited a far greater response in plasma insulin levels after glucose loading. Insulin response tests (0.4 iu/kg bwt insulin intravenously) showed only a minimal and very protracted response in both the fat and laminitic groups. The relevance of these findings in regulation of carbohydrate and lipid metabolism, and their role in the pathogenesis of hyperlipaemia, are discussed.
Albumin and immunoglobulins G, A and M in aqueous humour from clinically normal equine eyes
Authors: MATTHEWS A. G. , POULTER TESSA
Published: April 2010

The leveb of albumin, immunoglobulin G (including IgG [T]), IgA and IgM in the serum and aqueous humour of 47 horses and ponies with no ophthalmic abnormalities were determined by single radial immunodiffusion. There was a linear relationship between serum and aqueous albumin levels. No relationship of serum and aqueous IgG levels was observed. IgA was detected in only one aqueous sample. IgM was not detected in aqueous humour from any eye in this study. The factors which may influence albumin and immunoglobulin levels in normal aqueous humour are discussed.
Desmitis of the fetlock annular ligament in the horse
Authors: VERSCHOOTEN F. , PICAVET T‐M.
Published: April 2010

Desmitis of the fetlock annular ligament was diagnosed in 30 horses during a period of eight years. Most of the horses had been lame for a prolonged period and had chronically distended digital flexor tendon sheaths. Air tendograms demonstrated thickened palmar or plantar annular ligaments. In 25 horses the ligament was cut longitudinally; of these, 16 horses returned to full work without any difficulty and one became sound after a second operation. Follow up time varied from three months to seven‐and‐a‐half years. None of the five untreated horses returned to work.
Ground reaction force patterns of Dutch Warmblood horses at normal walk
Authors: MERKENS H. W. , SCHAMHARDT H. C. , HARTMAN W. , KERSJES A. W.
Published: April 2010

The ground reaction force patterns from 20 clinically sound Dutch Warmblood horses (Group A) were recorded at the normal walk. The data from four to 10 stance phases of each limb were computer averaged after normalisation to the animal's body mass and to the stance time. This analysis method allowed comparison of data from left and right fore‐ and hind‐limbs within and between horses. The left‐to‐right symmetry in the reaction force peaks of contralateral limbs of one horse exceeded 90 per cent. The time in the stance phase at which the peaks occur were even more symmetrically distributed. A characteristic force‐force diagram was constructed by plotting the longitudinal horizontal and the vertical ground reaction forces against each other; in this way the symmetry of loading of contralateral fore‐ and hindlimbs could be interpreted easily. Force plate tracings were obtained from eight horses (Group B) in three succesive years. The similarity of the tracings from a sound, well‐trained horse over that period was better than the differences between horses of the same breed.
Effects of amitraz, several opiate derivatives and anticholinergic agents on intestinal transit in ponies
Authors: ROBERTS M. C. , ARGENZIO A.
Published: April 2010

Amitraz, atropine, glycopyrrolate and morphine (but not its derivatives, meperidine [pethidine], oxymorphone and butorphanol) produced similar effects on clinically observed intestinal functions and significantly prolonged intestinal transit, as assessed with polyethylene glycol (peg). However, their mechanisms of action, particularly on intestinal transport (fluid movement), may differ widely. Loperamide appeared to exert a preferential action on intestinal transport rather than motility, as there was no significant delay inpegtransit. The action of amitraz in perturbing smooth muscle coordination and enhancing absorption involved, at least partially, an α2adrenergic component susceptible to yohimbine. Naloxone, an opiate antagonist, did not influence amitraz responses but induced the return of intestinal sounds and defecation after a refractory period in morphine‐dosed ponies. The results suggest potential clinical applications in horses for loperamide in diarrhoea therapy, for α2adrenergic antagonists in obstruction and ileus and, possibly, of amitraz‐like agents in reducing fluid losses in diarrhoea.
D‐xylose absorption in the growing foal
Authors: MERRITT TINA , MALLONÉE P. G. , MERRITT A. M.
Published: April 2010

Seven healthy foals (five ponies and two horses) were maintained on grass pasture with their dams. All foals had normal faeces at the time of testing. An oral xylose absorption test was performed on each foal at one, two and three months of age. Following an 8 h fast, 0.5 g/kg D‐xylose as a 10 per cent solution was given via a nasogastric tube. Control and 30 min interval plasma samples were collected for 3 h and the plasma was analysed for xylose using the phloroglucinol microassay technique. Maximum xylose concentration levels were reached between 30 and 60 mins for each of the foals. The mean (±sem) peak xylose concentration at one, two and three months of age was 3.14±0.29, 2.19±0.30 and 1.25±0.22 mmol/litre respectively, which were all significantly different from each other. Xylose absorption capacity decreased, therefore, with age, becoming similar to the adult horse by three months of age. The oral xylose absorption test can be used to evaluate small intestinal absorptive capacity in the foal provided that the results are compared with foals of the same age group.
Treatment of guttural pouch mycosis
Authors: CHURCH SALLY , WYN‐JONES G. , PARKS A. H. , RITCHIE H. E.
Published: April 2010

Seventeen cases of guttural pouch mycosis (including two bilaterally affected cases) were diagnosed in a three year period. The presenting signs were, in order of frequency, epistaxis at rest, nasal catarrh, pharyngeal paralysis, ipsilateral laryngeal hemiplegia, swelling of the submandibular/parotid region, extension of the head and neck and dyspnoea. Ligation of the origin of the internal carotid and occipital arteries was attempted in 10 of the cases exhibiting epistaxis. Bilateral ligation was performed on one animal with an untoward sequelae. Where surgery was successfully completed further haemorrhage was prevented in eight out of nine affected pouches (89 per cent). Medical treatment involving local administration of various antifungal preparations via a specially designed catheter and/or the oral administration of benzimidazole drugs was successful in eliminating the mycotic plaque in most cases. Cases which presented with pharyngeal paralysis were all fatal.
Detomidine: A new sedative for horses
Authors: CLARKE KATHY W. , TAYLOR POLLY M.
Published: April 2010

Detomidine, given intravenously at doses of 5 to 30 (mean 13) μ/kg bodyweight (bwt), provided adequate sedation for a variety of clinical procedures in 93 per cent of administrations, and improved the ease of handling in the remaining animals. Side effects of ataxia and bradycardia were minimal at the lower dose rates. Higher doses were required for intramuscular use. In experimental trials 10 and 20 μg/kg bwt resulted in deep sedation and also significant hypertension and bradycardia of over 15 mins duration. Current literature on the use of detomidine in horses is reviewed.
Study of arterial blood pressure in newborn foals using an electronic sphygmomanometer
Authors: FRANCO R. M. , OUSEY JENNY C. , CASH R. S. G. , ROSSDALE P. D. , SILVER MARIAN
Published: April 2010

An electronic sphygmomanometer which functions on oscillometric principles, was used to measure arterial blood pressure in foals. Its accuracy was assessed by comparison with results obtained by direct measurement in anaesthetised pony foals, aged 34 to 64 days. Correlations between data obtained by the two methods were highly significant but the sphygmomanometric readings were consistently lower than those obtained by direct measurement. An equation was derived from the pooled values for mean, systolic and diastolic pressure measurements. This was used as a correction factor when the oscillometric method was employed in the field on Thoroughbred foals, during the first three days post partum, and on pony foals during the first day only. There were no significant differences between systolic, diastolic and mean values in Thoroughbreds on Days 1, 2 or 3 after birth. Measurements recorded on the first day after foaling were significantly lower (P<0.025) in ponies than in Thoroughbreds. Blood pressure measurements in Thoroughbreds and ponies were substantially higher than those reported previously using the ultrasonic Doppler technique.
Early development of gait asymmetries in trotting Standardbred colts
Authors: DREVEMO S. , FREDRICSON I. , HJERTÉN G. , McMIKEN D.
Published: April 2010

Ten trotting Standardbred colts were recorded by high‐speed cinematography at the ages of eight, 12 and 18 months. The horses were trotting on a treadmill operating at 4.0 m/secs. Five horses were subjected to a programme of intensified training from eight months of age, whereas the others were not trained and acted as controls. The films were analysed on a semi‐automatic film‐reading equipment and a number of variables used to demonstrate the gait symmetry were calculated and scaled by computer. Certain differences between left and right diagonal and contralateral pair of limbs, respectively, were noted, suggesting that laterality in horses may be inherited. The most pronounced systematic differences were found in 18‐month old horses in the trained group. The results show the importance of careful gait examination and comprehensive coordination training at an early age.
Synthesis and absorption of cysteine from the hindgut of the horse
Authors: McMENIMAN N. P. , ELLIOTT R. , GROENENDYK S. , DOWSETT K. F.
Published: April 2010

The extent to which cysteine synthesised by microbes within the hindgut of the horse is incorporated into plasma cysteine was estimated by an isotopic technique in two horses fed four different diets. The results showed that between 1 per cent and 6 per cent of the plasma cysteine was of microbial origin. It is argued that the maximum contribution of microbial cysteine, and presumably other amino acids of microbial origin, to the plasma pool is 12 per cent of the net supply. These data support the hypothesis that microbial amino acid synthesis within the hindgut of the horse does not significantly affect its amino acid status.
Absorption of neomycin from the equine uterus: Effect of stage of oestrous cycle and volume of vehicle
Authors: BOYD ELIZABETH H. , ALLEN W. EDWARD
Published: April 2010

Plasma concentrations of neomycin were measured following intrauterine infusion of 3.3 mg/kg bodyweight neomycin sulphate. Mares in oestrus absorbed approximately 6 per cent of neomycin infused whereas mares in a luteal phase absorbed 56 per cent. The volume of infusate also affected absorption as increased volume resulted in decreased absorption. The decreased absorption both during oestrus and when large volumes were used was probably due to reflux of antibiotic through the cervix.
Factors influencing morbidity and outcome of equine ocular squamous cell carcinoma
Authors: SCHWINK KAY
Published: April 2010

A retrospective review of 41 cases of equine ocular squamous cell carcinoma with follow up information for 33 horses is presented. An apparent prevalence in heavy horse breeds was identified. Age and sex distribution were similar to those previously reported. High recurrence (42.4 per cent) and low metastasis (6 per cent) rates were seen. Initial tumour location, primary treatment used, or patient case history had no apparent influence on final outcome. The willingness of owners to pursue with continuous treatment correlated with a high degree of success.
Presence of salicylic acid in Standardbred horse urine and plasma after various feed and drug administrations
Authors: BEAUMIER P. M. , FENWICK J. D. , STEVENSON A. J. , WEBER M. P. , YOUNG L. M.
Published: April 2010

Plasma and urinary levels of salicylic acid were examined in Standardbred mares after administration of various feeds, containing different compositions of hay. In addition, horses were administered acetylsalicylic acid orally and methyl salicylate topically. Elevated salicylic acid levels were observed in horse urine and plasma in animals fed lucerne hay. The plasma and urinary elimination of salicylic acid exhibited a diurnal pattern which was related to the type of feed and the feeding schedule. Within 24 h after oral administration of acetylsalicylic acid, plasma and urine salicylic acid levels were consistent with residual levels observed after feeding lucerne hay. Elimination of salicylic acid was rapid and complete, with a half‐life between 5 and 7 h. Topical administration of methyl salicylate (8.4 g) produced elevated urinary salicylic acid levels for 6 h. A smaller dose of methyl salicylate (3.4 g) did not elevate plasma or urine salicylic acid levels above those observed following administration of lucerne hay.
Contrast radiography in the investigation of sinus tracts and abscess cavities in the horse
Authors: MAY S. A. , WYN‐JONES G.
Published: April 2010

Contrast radiography is a valuable technique in the investigation of infected foci in the horse. Its simplest form, a metal probe, will demonstrate the direction and, in the case of a short tract, the extent of the lesion. However, liquid contrast agents often give more information by following the course of long, tortuous sinus tracts, accurately delineating the boundaries of lesions and identifying the presence of foreign bodies.
Elective inversion of the distal ileal stump into the caecum of the horse
Authors: VASEY J. R. , JULIAN R. J.
Published: April 2010

The distal 30 to 40 cm of the ileum cannot be exteriorised through a midline laparotomy incision because of its close anatomical association with the base of the caecum. A method was developed to deal with those cases where this segment of small intestine was involved in an avascular, necrotic process and therefore required resection. The technique involves inverting the distal stump of ileum into the lumen of the caecum and then performing a routine ileocaecal or jejuno‐caecal anastomosis. This avoids the risk of peritonitis if a Parker‐Kerr oversew of the necrotic ileal stump should dehisce. The technique was performed on five clinically normal horses and on four horses in which the terminal 30 to 40 cm of the ileum was necrotic. The postoperative clinical findings and autopsy results of these horses are discussed.
Allergic dermatitis (sweet itch) of Icelandic horses in Sweden: An epidemiological study
Authors: BROSTRÖM H. , LARSSON Å. , TROEDSSON M.
Published: April 2010

A survey of allergic dermatitis (sweet itch) in Sweden contained information on 441 Icelandic horses. Results of a questionnaire indicated that approximately 15 per cent of the country's Icelandic horses suffered from the disease. The prevalence of allergic dermatitis was significantly higher among horses imported from Iceland (26.2 per cent) compared to that of Swedish‐born animals (6.7 per cent). In addition, horses born in Iceland were significantly more severely affected than horses born in Sweden. The risk of allergic dermatitis in Sweden appeared to be more than six times higher for horses exported from Iceland to Sweden relative to that of horses originally born in Sweden. The prevalence of disease for horses of seven years or older was 30 per cent for Icelandic‐born individuals as compared to 7.3 per cent for horses born in Sweden. Similarly, the risk of allergic dermatitis in Sweden for horses of seven years or older appeared to be nearly 10 times higher for horses imported from Iceland relative to that of horses born in Sweden. Allergic dermatitis usually appeared during the third grazing season for imported horses and during the fourth season for horses born in Sweden. Furthermore, the course of the disease tended to become worse with time. Analysis of the prevalence of allergic dermatitis relative to gender revealed no significant differences. Certain geographical variations in the prevalence of the disease was also found.
Growth and calcium metabolism in horses fed varying levels of protein
Authors: SCHRYVER H. F. , MEAKIM D. W. , LOWE J. E. , WILLIAMS J. , SODERHOLM L. V. , HINTZ H. F.
Published: April 2010

The effect of level of protein intake on growth and calcium metabolism was studied in 24 foals. Starting at four months old, the foals were fed one of three diets containing all nutrients, with the exception of protein, at levels recommended by the United States National Research Council Subcommittee on Horse Nutrition for a 12 month period. The protein levels in the three diets were 9 per cent (low protein) 14 per cent (NRC recommended level) and 20 per cent (high protein). The foals fed the low protein diet were changed to the high protein diet after 140 days when they were nine months old. There were no significant differences in the rates of growth in weight, height, cannon circumference or in hoof growth and feed utilisation of the horses fed the 14 or the 20 per cent protein diets. However, growth, feed intake and feed utilisation by the foals fed the low (9 per cent) protein diet were significantly depressed. The average daily gains for the first 140 days for the 9, 14 and 20 per cent protein treatment groups were 64, 631 and 687 g in weight, 0.57, 0.83 and 0.87 mm in height and 0.04, 0.13 and 0.14 m in forecannon circumference, respectively. The average daily feed intakes for the 140 day period for the three groups were 2.7, 4.4 and 4.7 kg, respectively. After the change to the high protein diet the foals that had been fed the low protein diet maintained a higher rate of gain in bodyweight, height and cannon circumference, and utilised feed more efficiently than the other two groups throughout the second 140 days of the experiment. At the end of the second 140 days there were no longer differences in weight, height or cannon circumference among the treatment groups. Calcium and phosphorus balance studies were carried out using three foals from each treatment group when they were six months old and repeated with the same horses when they were 12 months old. Urinary calcium excretion averaged 23 to 30 per cent of calcium intake and calcium absorption averaged 52 to 77 per cent of intake. Neither was affected by the protein content of the diet. Bone turnover, as measured with 47Ca, was depressed in the foals fed the low protein diet. A concentration of dietary protein of 20 per cent which is significantly greater than the NRC recommended level of 14 per cent is neither helpful nor harmful to growing horses.
Unilateral distension of the tarsal sheath in the horse: A report of 11 cases
Authors: DIK K. J. , MERKENS H. W.
Published: April 2010

Eleven horses with unilateral distension of the sheath are reported with emphasis on the use of plain and contrast radiography in diagnosis. Six had associated bony abnormalities of the sustentaculum tali, and two of these showed destructive or mixed destructive and proliferative lesions resulting from osteomyelitis. One horse had a fracture of the sustentaculum. In three horses proliferative changes were found. Bony changes were best demonstrated on a dorsomedial‐plantarolateral oblique view. Contrast radiography of the tarsal sheath was performed In five cases without, and two horses with, associated bony lesions. In five cases ballooning with or without folding of the proximal aspect of the sheath was demonstrated. Additional band‐like filling defects (two cases), triangular filling defect (one case), nodular intra‐tendovaginal masses (two cases), or an extra‐tendovaginal mass (one case) were noticed. The remaining two horses showed a semicircular collar shape dilation of the proximal aspect of (he sheath. Contrast radiography appeared to be a helpful tool for the examination of tarsal sheath lesions. Two horses with associated bony changes were destroyed immediately after diagnosis, one failed to recover following surgical intervention and in three horses the outcome was unsatisfactory after conservative treatment. Three horses without associated bony lesions recovered completely after conservative treatment. One was operated on subsequently; the results are promising but the outcome of this case is not yet known. One was sold shortly after diagnosis and lost to follow up.
Observations and management of fractures of the proximal phalanx in young Thoroughbreds
Authors: ELLIS D. R. , SIMPSON D. J. , GREENWOOD R. E. S. , CROWHURST J. S.
Published: April 2010

A retrospective study of 119 cases of fracture of the proximal phalanx is described. The short incomplete sagittal fracture (split pastern) was most common and carried a good prognosis for a return to racing following conservative treatment. Longer incomplete fractures also had a good prognosis but complete fractures, either through the lateral cortex of the proximal phalanx or through the bone into the proximal interphalangeal joint, required internal fixation. Careful assessment of these and comminuted fractures was essential before surgery was undertaken. Most comminuted fractures were treated with a view to the animal retiring to stud rather than racing again. Humane destruction was considered to be justifiable for such fractures in colts or geldings of no stud value or if the fracture was severely comminuted.
Use of an elisa in the differential diagnosis of cauda equina neuritis and other equine neuropathies
Authors: FORDYCE P. S. , EDINGTON N. , BRIDGES G. C. , WRIGHT JANE A. , EDWARDS G. B.
Published: April 2010

In 27 potential neuropathies an enzyme‐linked immunosorbant assay, using P2 preparations from either bovine or equine myelin, detected all cases of cauda equina neuritis in which there was caudal involvement. The test was of limited value in differentiating neuropathies involving only cranial or other peripheral nerves.
Funding equine research: Experiences at the University of Saskatchewan
Authors: POLLEY L.
Published: April 2010

The Western College of Veterinary Medicine (WCVM) at the University of Saskatchewan has, over the past 10 years, developed a cooperative venture with the horse industry in western Canada for financial support of graduate training and research programmes related to the horse. This has been organised through the WCVM Equine Health Research Fund. This paper describes the establishment and development of the fund. It is hoped that the information may be of benefit to others wishing to initiate or enhance similar programmes.
Exercise‐induced pulmonary haemorrhage: Exercise‐induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. I. Clinical profile of horses
Authors: O'CALLAGHAN M. W. , PASCOE J. R. , TYLER W. S. , MASON D. K.
Published: April 2010

Detailed physical and clinical examinations were performed on 26 Thoroughbred racehorses which were used subsequently in a series of studies to investigate the contribution of the pulmonary and bronchial arterial circulations to the pathophysiology of exercise‐induced pulmonary haemorrhage (EIPH). Twenty‐five of the horses had been retired from race training in Hong Kong during the 1984‐85 season, all but four raced that season; one horse had been retired the previous season. The average number of races for the group that season was 4.1 ± 2 with an average distance of 1502 ± 216 metres, mean racing speed 15.5 ± 0.5 metres/sec. Time from last race to necropsy was 177 ± 155 days, range 12 to 572 days. All but one horse had a known history of either EIPH or epistaxis. Time from last recorded incident of expistaxis (17 horses) to necropsy was 156 ± 141 days, range 12 to 513 days, with a longer interval since last recorded endoscopic observation of EIPH. Focal abnormal lung sounds were detected in the dorsocaudal lungfields on auscultation during rebreathing in three horses and six had tracheobronchial cytology consistent with previous episodes of pulmonary haemorrhage (haemosiderophages). No other characteristics which might have allowed separation of this group of horses from other Thoroughbred horses recently in race training were identified.
Exercise‐induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. IV. Changes in the bronchial circulation demonstrated by C. T. Scanning and microradiography
Authors: O'CALLAGHAN M. W. , PASCOE J. R. , TYLER W. S. , MASON D. K.
Published: April 2010

The purpose of this study was to use radiographic contrast techniques and special imaging methods to identify and highlight bronchial arterial involvement in lung lesions associated with exercise‐induced pulmonary haemorrhage (EIPH) in horses. The lungs from four horses with histories of EIPH were prepared for computerised tomographic scanning and microradiography by perfusing the broncho‐oesophageal artery with a mixture of red latex and either barium or iodine contrast materials while the pulmonary supply received only blue latex. Computerised tomographic scan slices of the prepared inflated lungs were obtained from the caudal tip of the lung to the hilus. Microradiography of selected lung slices was also performed on a Faxitron. Diffuse areas of increased density, with preferential bronchial arterial supply noted on the computerised tomographic scans were confirmed by microradiography. Dense focal and diffuse plexuses of markedly hypertrophied and highly branched bronchial arterial networks were identified, centred around certain small airways. The vascular supply to these plexuses was recruited predominantly from neighbouring bronchial vessels, and in some cases, from the enlarged vasa vasorum of pulmonary arteries sending anastomoses to the affected areas. The authors conclude that bronchial vascular lesions in EIPH cases are the likely origin of haemorrhage; that small airway disease is the probable initiating stimulus for bronchial vascular proliferation in these lesions; and that the morphology and nature of the neovascular tissue in these lesions provides the conditions leading to haemorrhage in the lungs of horses with EIPH.
Oral administration of ascorbic acid to horses
Authors: SNOW D. H. , GASH S. P. , CORNELIUS J.
Published: April 2010

The effects of oral administration of high doses of ascorbic acid on plasma concentrations were investigated in both experimental Thoroughbred horses and those within racing stables. A single oral dose (20 g) did not result in any increase in plasma concentrations. However, daily administration of either 4.5 g or 20 g doses resulted in significant increases in plasma concentrations. Monthly variations in plasma ascorbate concentrations were found in both supplemented (20 g daily) and unsupplemented stables. It is concluded that oral supplementation with ascorbic acid is a satisfactory route to increase plasma and tissue concentrations.
Equine paranasal sinus cysts: A report of 15 cases
Authors: LANE J. G. , LONGSTAFFE J. A. , GIBBS CHRISTINE
Published: April 2010

The clinical and radiographic features of 15 cases of paranasal sinus cysts are described. Breed, sex and side frequency were unremarkable but two distinct categories of age incidence emerged. Onset of signs had occurred before one year of age in three cases, while all but two of the remaining 12 animals were older than nine years. The most common clinical signs were nasal airway obstruction, facial swelling and nasal discharge, often occurring in combination. Radiographic changes were recorded in all horses. Sinus opacification was a consistent finding and in several cases the bone surrounding the sinus had increased in thickness. Increase in intra‐maxillary sinus pressure was demonstrated by septal displacement on ventro‐dorsal radiographs in almost half the cases. Less common signs included expansion, free fluid accumulation within the affected sinus, dental distortion and displacement and mineralisation. Two horses were destroyed without treatment but in 13 animals surgical exploration was performed. Two of these were destroyed, one at the time of surgery and one five days postoperatively. In the remaining 11 cases, all accessible parts of the cyst were removed through a facial flap and drainage to the nasal meati was established. All these horses recovered satisfactorily and were followed up for periods between three months and six years without evidence of recurrence. Thirteen cysts arose in the caudal maxillary sinus and one each in the frontal and rostral maxillary compartments. Histopathological examination of portions of the cyst walls suggests that, like ethmoidal haematomas, they may originate from episodes of haemorrhage beneath the upper respiratory tract mucosa.
Exploratory celiotomy for suspected urinary tract disruption in neonatal foals: A review of 18 cases
Authors: ADAMS RAGAN , KOTERBA ANNE. M. , CUDD T. C. , BAKER W. A.
Published: April 2010

The medical records of 18 neonatal foals, in which exploratory celiotomies were performed for suspected urinary tract lesions, were reviewed. Despite clinical signs and laboratory values indicative of disruption of the urinary tract, three foals did not have a site of urinary tract leakage at surgery. Eight foals had ruptured bladders and seven foals had urachal lesions. Ultrasonography was used as a pre‐operative diagnostic procedure in eight foals to evaluate the presence of free peritoneal fluid and urinary tract integrity. Nine foals were alive six months after discharge. Seven of the nine non‐surviving foals died or were destroyed because of fungal or bacterial infections.
Development of a scoring system for the early diagnosis of equine neonatal sepsis
Authors: BREWER BARBARA D. , KOTERBA ANNE M.
Published: April 2010

A sepsis scoring system was developed and tested prospectively in a blind study of 190 neonatal foals admitted to the University of Florida Veterinary Medical Teaching Hospital's neonatal intensive care unit. The system used 14 readily available historical, clinical or laboratory variables and weighted each item to arrive at a sepsis score. The score was found to have a sensitivity of 93 per cent, a specificity of 86 per cent, positive accuracy rate of 89 per cent and negative accuracy rate of 92 per cent. The sepsis score was far more sensitive and specific for infection, even in very early cases, and had fewer false positive and false negative values than did any parameter taken individually.
Use of stapling instruments to aid in the removal of ovarian tumours in mares
Authors: DORAN R. , ALLEN D. , GORDON B.
Published: April 2010

Ovarian granulosa theca cell tumours were removed surgically in 10 mares. Stapling instruments were used to facilitate haemostasis of the ovarian pedicle in five out of 10 cases and as a sole method of haemostasis in the remaining five cases. Postoperative haemorrhage from the ovarian pedicle was suspected in only one case. All cases survived long term follow‐up from six months to four years. Results from this series of cases indicate that stapling instruments provide a rapid, easy and efficient means of ligating ovarian pedicles when performing ovariectomy in the mare.
Enzyme histochemistry on muscle biopsies as an aid in the diagnosis of diseases of the equine neuromuscular system: A study of six cases
Authors: van den HOVEN R. , MEIJER A. E. F. H. , BREUKINK H. J. , WENSING Th.
Published: April 2010

Muscle biopsies from six horses with clinical histories of muscle atrophy, muscle tremors, myopathic symptoms, unsteadiness of pelvic limbs and progressive ataxia were examined. Muscle biopsies were studied with enzyme histochemical techniques to evaluate the diagnostic values of these methods in cases suspected of suffering from neuromuscular disorders. Hypertrophy, atrophy, fibre splitting, waxy degeneration, phagocytosis and necrosis were seen in haematoxylin eosin stained sections of the different cases. Fibre type predominance and fibre type grouping were seen in the calcium ion stimulated myosine ATP‐ase (Ca‐ATP‐ase) stained sections of some cases. ‘Moth‐eaten fibres’ were demonstrated in three cases by staining with NADH: nitro blue tetrazolium oxidoreductase (NADH‐TR), succinale dehydrogenase (SDH), NADH dependent malate dehydrogenase, cytochrome c oxidase and by lactate dehydrogenase. The catabolic enzymes, acid phosphatase (ACP) and 5′‐nucleotidase were active in cases with fibre phagocytosis. The oxidative part of the pentose phosphate pathway in myopathic tissue seemed to be important in three cases, demonstrated by the increased activity of glucose‐6‐phosphate dehydrogenase (GPDH) and 6‐phosphogluconate dehydrogenase (PGDH). The important feature of diseased horse muscle was that the pathohistochemical changes were exactly the same as in diseased skeletal muscles of humans. The application of tissue saving enzyme histochemical techniques can be recommended in the study of muscle tissue from horses suffering from suspected neuromuscular disorders.
Quantification of skin displacement near the carpal, tarsal and fetlock joints of the walking horse
Authors: VAN WEEREN P. R. , VAN DEN BOGERT A. J. , BARNEVELD A.
Published: April 2010

A technique enabling simultaneous visualisation of skin and underlying bony structures in the walking horse was used to quantify skin displacements on the lateral surface of carpal, tarsal and fetlock joints. The technique employed implanted light‐emitting‐diodes (LEDs) for marking the bone, and self adhesive spot labels for marking the overlying skin. Photographic recordings were made. Skin displacement was measured in six Dutch Warmblood horses. Mean total displacements and mean displacement per degree of change of joint angle were calculated. Displacements at the level of the fetlock joints appeared to be generally small (≤ 2 mm), but displacements up to 2 cm were measured in the distal tibia. Displacements of this magnitude are of importance for the interpretation of results obtained by modern gait analysis techniques.