bluuebunny/crossref_metadata_2025 huggingface dataset:
The raising of equine colostrum‐deprived foals; maintenance and assessment of specific pathogen (EHV‐1/4) free status
Authors: CHONG Y. C. , DUFFUS W. P. H. , FIELD H. J. , GRAY D. A. , AWAN A. R. , O'BRIEN M. A. , LUNN D. P.
Published: April 2010

Over a period of two years, a total of 22 full term foals from Welsh Mountain pony mares were raised in conditions that were free from infection by Equid herpesvirus (EHV‐1/4). Parturition dates were predicted by monitoring colostrum electrolytes, and the mares allowed to foal naturally under supervision or following induction with intravenous oxytocin. Immediately following birth, foals were separated from their dams and transferred to a specially built, positive pressure isolation unit. They were given antibiotic prophylaxis and fed bovine colostrum during the first 24 h, and then mare's milk replacer until weaned. Out of 22 specific pathogen free (SPF) foals one that had not been given antibiotic prophylaxis died of anE. colisepticaemia aged eight days. Two foals developed a streptococcal upper respiratory tract infection, which responded to antibiotic therapy and did not spread to the rest of the herd. A self limiting upper respiratory tract infection was seen in a fourth foal and mild diarrhoea was observed in six foals. Physical development in all SPF foals appeared normal and behavioural patterns resembled those of conventional hand‐reared foals. Newborn foals were held in a separate quarantine area, within the isolation unit, and checked extensively for evidence of EHV‐1/4 infection, before being transferred to the main holding unit. Periodic checks were then made for EHV‐1/4 over a period ranging from 2 to 4 months; none of the SPF foals showed evidence of infection with EHV‐1/4 in terms of clinical disease, virus isolation, sero‐conversion or specific lymphocyte transformation.
A study of bovine and equine immunoglobulin levels in pony foals fed bovine colostrum
Authors: HOLMES M. A. , LUNN D. P.
Published: April 2010

As part of a project to raise specific pathogen free (SPF) Welsh Mountain Pony foals, free from exposure to Equid herpesvirus type 1, foals were removed from their dams at birth and fed bovine colostrum. This study characterises the uptake of bovine colostral immunoglobulin and production of endogenous immunoglobulin, in 10 SPF foals. An enzyme‐linked immunoadsorbant assay was developed to measure serum concentrations of bovine IgG1(boIgG1) to assess the efficiency of transfer, and rate of elimination of boIgG1by the foal. The endogenous production of equine IgG was studied using a single radial immunodiffusion test Foals were given 1.2 to 2 litres of bovine colostrum achieving peak serum boIgG1concentrations of 18.9 to 34.2 g/litre (mean 28.0). The mean half‐life of boIgG1in the foals was 7.4 days. Endogenous immunoglobulin production resulted in equine IgG concentrations >2 g/litre in six of 10 foals by 14 to 19 days of age, and >6 g/litre in eight of 10 foals by 37 to 50 days of age. All foals had equine IgG serum concentrations >10 g/litre by 102 to 135 days of age.
Maternal and umbilical venous plasma lipid concentrations at delivery in the mare
Authors: STAMMERS J. P. , HULL D. , LEADON D. P. , JEFFCOTT L B. , ROSSDALE P. D.
Published: April 2010

The concentrations and fatty acid composition of the plasma free fatty acid, triacylglycerol and phospholipid fractions were determined in maternal and umbilical cord vein blood samples taken at delivery from 17 mares. Maternal and umbilical vein plasma free fatty acid concentrations were of a similar order and a positive correlation was found between the two levels suggesting that the equine placenta is permeable to fatty acid. Substantial amounts of the essential fatty acids and their longer chain derivatives were seen in both umbilical vein plasma free fatty acid and phospholipid fractions supporting this view. Certain long chain polyunsaturated derivatives of the essential fatty acids found in the umbilical venous plasma phospholipid fraction were not seen in the maternal circulating lipids. The precursor fatty acids were readily available to both foetal and placental tissues and therefore must have been elongated and incorporated into phospholipid by either or both. Very small amounts of the essential fatty acids were found in adipose stores in the newborn foal and virtually no fat stores at all in the newborn foal liver.
Lameness due to pain associated with the distal interphalangeal joint: 45 cases
Authors: DYSON SUE J.
Published: April 2010

This paper describes the clinical and radiographic features, and response to treatment, of 45 horses which showed lameness that was improved by intra‐articular anaesthesia of the distal interphalangeal (DIP) joint. Although many horses had poor conformation of the foot of the lame limb, the majority showed no localising clinical signs suggestive of involvement of the DIP joint. Lameness was usually unilateral. No horse with bilateral lameness responded to treatment. Palmar digital nerve blocks frequently improved or alleviated lameness, although in some horses palmar (abaxial sesamoid) nerve blocks were required to eliminate lameness. This difference in response did not affect response to treatment. Intra‐articular anaesthesia of the DIP joint usually resulted in resolution of lameness within 5 mins; a partial improvement in lameness or a slow response were poor prognostic indicators. None of the horses had radiographic abnormalities compatible with navicular disease. Radiographic changes of the distal interphalangeal joint per se were generally detectable only in lateromedial views and were identified in less than one third of the horses. Success rates were low following treatment of cases with radiographic abnormalities. In those with no radiographic abnormalities the response to corrective trimming and shoeing and intra‐articular administration of sodium hyaluronate, once or repeatedly, was variable and no parameters could be used to predict the likely outcome. Treatment was successful in approximately 30 per cent of cases. Subsequent treatment of horses which remained lame, by intraarticular administration of polysulphated glycosaminoglycans, was not helpful; only a small proportion became sound following prolonged (nine months) rest. The overall poor success rate of treatment and the results of post mortem examination of three horses which failed to respond to treatment, demonstrated the limitations of radiographic evaluation of this area. More importantly, it is still not clear which structures can be affected by intra‐articular anaesthesia of the DIP joint.
Comparison of yearling, two‐year‐old and adult Thoroughbreds using a standardised exercise test
Authors: SEEHERMAN HOWARD J. , MORRIS ELISABETH A.
Published: April 2010

The purpose of this study was to compare exercise measurements in yearling, two‐year‐old and adult Thoroughbreds using a standardised treadmill incremental exercise test. Peak oxygen consumption (V̇O2peak: 128.0 ± 2.1, 140.0 ± 2.1, 163.7 ± 3.4; ml/kg/min ± se, P<0.05), peak packed cell volume (PCVpeak: 0.50 ± 0.01, 0.58 ± 0.01, 0.64 ± 0.01litres/litre ± se, P<0.05) and the maximum number of steps completed in the exercise test (STEPmax: 7.7 ± 0.1, 8.1 ± 0.1, 8.6 ± 0.1; steps ± se, P<0.05) increased with age and degree of physical activity. Peak venous lactate concentration (LACpeak: 21.3 ± 1.5, 19.5 ± 1.7, 14.4 ± 1.7; mmol/litre ± se, P<0.05) and peak respiratory exchange ratio (Rpeak) were significantly higher in both groups of younger horses compared to the adult racehorses. Peak heart rate (HRpeak: 230 ± 2, 231 ± 3, 229 ± 3; beats/min ± se) did not change with age or training. The rate of change of V̇O2between steps in the exercise test (V̇O2trans) was significantly lower in the adult racehorses at the highest exercise intensities. The slopes of the linear approximation between R (LinR bx), the natural log transformation of venous lactate concentration (LogLAC bx), and heart rate (HR bx) with velocity were significantly lower in the trained adult racehorses. The slope of venous lactate concentration normalised to per cent V̇O2peak (LogLAC per cent bx) was significantly lower and R breakpoint (R brkpt) normalised to per cent V̇O2peak was significantly higher in the trained adult racehorses. There was a more rapid decrease in venous lactate and a more rapid return to initial R values in the adult horses relative to the younger, untrained horses. No significant age or training effects were found in the remainder of the post exercise measurements. These results indicate that aerobic power and exercise capacity increased with age and training. Anaerobic power was already well developed even at a young age.
Titrimetric determination of muscle buffering capacity (βmtitr) in biopsy samples
Authors: MARLIN D. J. , HARRIS R. C.
Published: April 2010

In vitro titration of muscle homogenates has been used to assess muscle buffering capacity (βmtitr) in a variety of species. In the present study, factors likely to affect the estimation of βmtitr were investigated. Also, values of βmtitr from normal Thoroughbred horses are presented. A non‐linear titration curve was obtained with addition of HCl to muscle homogenates. As a result, βmtitr is expressed as the μmol H+ required to change the pH of 1g of dry muscle or wet muscle from 7.1 to 6.5. An effect of dilution on the initial pH was found below 40 mg wet muscle per ml homogenising reagent (10 mg dry muscle per ml) and on βmtitr below 10 mg wet muscle. As a result, 40 mg wet muscle or 10 mg dry muscle per ml was chosen as the minimum concentration for determination of βmtitr. Incubation of homogenates up to 60 mins did not affect βmtitr significantly. As a mean, βmtitr in wet muscle was approximately 25 per cent higher compared to dry muscle. The βmtitr of dry muscle was increased by approximately 18 per cent when HCO3− was added in an amount equivalent to the calculated HCO3− content of wet muscle at rest. The homogenisation process resulted in complete loss of adenosine triphosphate and phosphocreatine with only small changes in adenosine diphosphate and adenosine monophosphate. It was concluded that the estimates of βmtitr did not include any contribution from ‘dynamic’ buffering via rephosphorylation of adenosine diphosphate by phosphocreatine, and in dry muscle it was accounted for mainly through physico‐chemical buffering by phosphates, proteins and dipeptides. βmtitr determined in biopsy samples of muscle from 20 Thoroughbred horses ranged from 100.8 to 131.8 μmol H+/g dry muscle pH 7.1 to 6.5 (mean 121.2, sd ± 7.4).
Muscle characteristics in Thoroughbreds of different ages and sexes
Authors: RONËUS M. , LINDHOLM A. , ÅSHEIM Å.
Published: April 2010

Muscle biopsies were taken from the middle gluteal muscle in 163 healthy Thoroughbreds aged one to six years. The horses were separated according to sex and divided into four different age groups (one, two, three and four to six years). Muscle biopsies were analysed for fibre type (I, IIA and IIB), and the enzyme activities of citrate synthase, 3‐OH‐acyl‐CoA dehydrogenase, lactate dehydrogenase and hexokinase were measured. The percentage of Type I fibres of all horses increased with age, irrespective of sex (from 9 to 16 per cent). The percentage of Type IIA fibres varied with age and sex, increasing in stallions from 34 to 53 per cent and in mares from 27 to 45 per cent, respectively. Correspondingly, the proportion of Type IIB fibres decreased with age and differed between sexes (stallions from 56 to 29 per cent and mares from 65 to 40 per cent). Muscle oxidative capacity increased with age as indicated by significant increases in the activities of citrate synthase (from 32 to 67 mmol/kg/min) and 3‐OH‐acyl‐CoA dehydrogenase (from 20 to 34 mmol/kg/min). The activity of hexokinase increased with age (from 2.4 to 4.8 mmol/kg/min), whereas the activity of lactate dehydrogenase decreased (from 1,754 to 1,444 mmol/kg/min). No differences were seen between stallions and mares in enzyme activities. This study shows that age is one factor influencing enzyme activities, the percentage of Type I fibres and the Type IIA/IIB ratio in M. gluteus medius of Thoroughbreds, and that stallions have a higher Type IIA/IIB ratio compared with mares.
Prevalence of serum precipitating antibodies in horses to fungal and thermophilic actinomycete antigens: effects of environmental challenge
Authors: MADELIN T. M. , CLARKE A. F. , MAIR T. S.
Published: April 2010

Sera from 54 two‐ to three‐year‐old Thoroughbred horses from an English racing stable were examined for precipitins to antigen extracts prepared from 18 species of moulds (fungi and thermophilic actinomycetes) isolated from the same stable. Twenty‐seven horses exhibited serum precipitins to one or more antigens; sixteen of the mould antigens elicited positive reactions in sera from one or more horses. Significantly more precipitins occurred in sera of those horses stabled in a barn than among those stabled in individual boxes. This indicated a possible association between type of housing, level of exposure to airborne moulds and presence of serum precipitins. None of the horses had overt respiratory disease. This study agrees with reports of the presence of serum precipitating antibodies to mould antigens in clinically healthy horses and confirms that serological tests, therefore, are of little value in the diagnosis of chronic obstructive pulmonary disease (COPD) or ‘heaves’.
Distribution of leucocyte antigens in Icelandic horses affected with summer eczema compared to non‐affected horses
Authors: HALLDÓRSDÓTTIR S. , LAZARY S. , GUNNARSSON E. , LARSEN H. J.
Published: April 2010

Three hundred and three horses, exported from Iceland to Norway, Sweden, Denmark, Switzerland or Germany were tested for their distribution of leucocyte antigens. One hundred and thirty‐six horses were affected with summer eczema. The panel of sera recognised the internationally accepted ELA‐specificities A 1 to A10, and the nine work shop specificities W 11 to W 15 and W 18 to W 21. Also, some local specificities, characterised in Switzerland (Be I, Be III, Be 8, Be 25, Be 26, Be 27), and two non major histocompatibility complex (MHC)‐linked antigens (Ely 1:1, Ely 2) were included. Only one antigen, Be 8, gave a statistically significant difference in distribution between the two populations: Relative risk = 2.5, x2= 10.11, corrected P < 0.01.
Intake, digestion and gastrointestinal transit time in resting donkeys and ponies and exercised donkeys given ad libitum hay and straw diets
Authors: PEARSON R. ANNE , MERRITT JANE B.
Published: April 2010

Four donkeys and four ponies maintained in climate rooms, were provided with meadow hay or barley straw supplemented with minerals and vitamins ad libitum. Both diets were given to all animals for periods of 21 days. Measurements were made during the last seven days following single doses of two non‐absorbable markers (Crfibre and Co‐EDTA). After six weeks the donkeys repeated the trial, walking 14 km and ascending 260 m five days per week. At rest ponies ate more than donkeys, however the donkeys showed a higher digestibility of dry matter (DM), organic matter (OM) and acid detergent fibre (ADF) than the ponies. Both species lost weight, ate less and had a lower digestibility of DM, OM and energy on the straw than on the hay ration. Fibre digestibility (neutral detergent fibre [NDF] and ADF) was higher on the straw than the hay diet. Gastrointestinal transit time was slower in the donkeys than in the ponies on both diets. Both species showed a higher mean retention time of digesta on straw than on hay. Exercise had no significant effect on food intake and liveweight changes in the donkeys. Although digestibility coefficients were higher in exercised animals, the effect was not significant. We conclude that, although it is generally considered that donkeys can thrive better on poor feeds than ponies, when the animals are allowed ad libitum access to hay and straw better intakes by ponies may compensate for any differences in digestibility seen in donkeys. Intake of barley straw by both species was not sufficient to meet maintenance requirements.
Clinical and biochemical features of grass sickness (equine dysautonomia)
Authors: DOXEY D. L. , MILNE E. M. , GILMOUR J. S. , POGSON D. M.
Published: April 2010

An attempt has been made to assess the diagnostic value of clinical features seen at initial examination of horses with grass sickness, colic cases and cases submitted as possible grass sickness but diagnosed subsequently as some other condition. There appears to be no single pathognomonic sign for grass sickness. A range of signs has been associated with grass sickness but these are of value only when related to the length of illness and the history. Biochemical tests related to intestinal tissue damage, stress and dehydration were evaluated and most were found to be of value in diagnosing acute grass sickness. No evidence was found relating selected mineral or vitamin deficiencies to grass sickness, nor were protein changes specific. A marked fall in glutathione peroxidase values was associated with grazing rather than disease.
A preliminary study of the tolerance of healthy foals to a low residue enteral feeding solution
Authors: KOHN CATHARINE. W. , KNIGHT D. A. , JEAN K. E. YVORCHYK‐ST. , SCAMAN P. A. , RUEY P. R.
Published: April 2010

After a three day acclimatisation period, six healthy, young (aged 4 to 20 days) orphan foals of mixed breeding were fed 100 per cent of their caloric needs (estimated at 523 kjoules/kg bodyweight [bwt] or 125 kcal/kg bwt/day) as a low residue isotonic feeding solution (LRF) for seven days. The solution provided 4.18 kjoules (1 kcal/ml) and was fortified with minerals and protein to meet estimated foal requirements. The solution was fed through an indwelling 12 French feeding tube. Five of the six foals completed the study; the loss of the sixth foal apparently was unrelated to the feeding protocol. The foals tolerated LRF well. Signs of intolerance were noted in two foals and were limited to flatulence, mild bloat and very mild abdominal pain associated with a decreased interval between two feedings during the first 48 h on 100 per cent LRF. Complete recovery without therapy occurred within 6 h and feedings were resumed. Growth in height and weight were comparable to published data for healthy foals raised with their dams. Feeding tubes were easily maintained with no apparent dysphagia, regurgitation or discomfort to foals. This low residue, calorically dense, isotonic feeding solution may be useful for enteral feeding of selected foals aged at least seven days.
Adverse conditions in vitro stimulate chondrocytes to produce prostaglandin E2 and stromelysin
Authors: MAY S. A. , HOOKE REBECCA E. , LEES P.
Published: April 2010

Chondrocytes subjected to adverse culture conditions in vitro are stimulated to produce the eicosanoid prostaglandin E2 (PGE2) and the neutral metalloproteinase stromelysin (proteoglycanase). This indicates the potential role of the chondrocyte in cartilage degeneration in equine clinical joint disease and suggests a mechanism which may be involved in the potentiation of the effects of other inflammatory mediators. Therefore, adverse conditions within the joint, such as decreased pH in an inflammatory focus and decreased access of nutrients to deeper layers of cartilage, might contribute to the activation of chondrocytes which leads to cartilage degradation.
Equine monocytic ehrlichiosis (Potomac horse fever): a review
Authors: MULVILLE P.
Published: April 2010

In the late 1970s, a new infectious disease in horses, involving acute enteritis, was recognised in the Potomac River area of Maryland, U.S.A. The causative agent was identified subsequently as a new species of rickettsial organism, later namedEhrlichia risticii.Since then, the disease has been reported in many other states, and in enzootic areas vaccination is common. Signs associated with the clinical disease included depression, fever, anorexia, decreased or absent intestinal sounds, profuse watery diarrhoea and laminitis. However, considerable variation in clinical manifestations has been reported in both the natural and experimental disease. Accurate diagnosis depends on serological testing; currently, the immunofluorescent antibody test (IFA) is used widely, although an enzyme‐linked immunosorbent assay (ELISA) has been developed recently. Mortality in untreated cases is 15 to 35 per cent. Antibiotics of the tetracycline series have shown activity against the organismin vitro, in anin vivomurine model and appear to be useful in clinical cases.
The prevalence of enteric pathogens in diarrhoeic Thoroughbred foals in Britain and Ireland
Authors: BROWNING G. F. , CHALMERS R. M. , SNODGRASS D. R. , BATT R. M. , HART C. A. , ORMAROD S. E. , LEADON D. , STONEHAM S. J. , ROSSDALE P. D.
Published: April 2010

A survey of 77 normal and 326 diarrhoeic foals in Britain and Ireland from 1987 to 1989 revealed a significantly higher prevalence of Group A rotaviruses andAeromonas hydrophilain diarrhoeic foals. The prevalence of cryptosporidia, potentially pathogenicEscherichia coli, Yersinia enterocoliticaandClostridium perfringenswas similar in normal or diarrhoeic foals. Rotaviruses had a similar prevalence in all age groups of scouring foals up to three months of age, with an overall prevalence of 37 per cent among diarrhoeic foals. The number of cases of diarrhoea varied considerably from year to year, but in all three years of the survey rotavirus was a significant pathogen. A comparison of diagnostic tests for rotavirus in the faeces showed electron microscopy (EM) and polyacrylamide gel electrophoresis (PAGE) to have similar sensitivity. The Rotazyme ELISA test kit was found to have the same sensitivity as a combination of EM and PAGE.A. hydrophilahad an overall prevalence of 9 per cent among diarrhoeic foals, although its prevalence was higher in some age groups.A. hydrophilahas not been established previously as a significant enteric pathogen in foals. Other putative pathogens found at very low prevalence were coronavirus, the putative picobirnavirus,Campylobacterspp. andSalmonellaspp. No evidence was found of synergistic effects between rotavirus, cryptosporidia and potentially pathogenicE. coli.Neither coccidia nor non‐Group A rotaviruses were found in any of the samples examined.
Influence of age on neutrophil function in foals
Authors: WICHTEL M. G. , ANDERSON K. L. , JOHNSON T. V. , NATHAN U. , SMITH L.
Published: April 2010

Functional activities (phagocytosis and killing) of neutrophil leucocytes (NL) and immunoglobulin G concentrations were evaluated in six healthy foals from birth to 6 months of age. Peripheral blood NL were reacted withStreptococcus equisimilisin 20 per cent pooled equine serum for 30, 60 and 90 mins and functional activities of NL were determined using a fluorochrome microassay. Values for foal NL function were compared with those of healthy adult horses (n = 28). Foal neutrophil function was influenced by age. Killing capacity of NL decreased, whereas phagocytic capacity increased, until 113 days of age, after which a reversal in trends became apparent. Immunoglobulin G concentrations changed significantly over time and were lowest at 29 to 56 days of age. All foal values for NL function fell within the range of normal values established for healthy adult horses.
Diagnosis of Equid herpesviruses −1 and −4 by polymerase chain reaction
Authors: SHARMA P. C. , CULLINANE A. A. , ONIONS D. E. , NICOLSON L.
Published: April 2010

The polymerase chain reaction (PCR) is a sensitive technique used to detect DNA of viral pathogens. We have applied the technique to the detection of Equid herpesviruses‐1 and −4 (EHV‐1 and EHV‐4) DNA within nasopharyngeal swab samples from horses. Ninety‐eight samples from suspected field cases and in‐contact horses were analysed. The assays were conducted blind and later decoded and compared with virus isolation data. Our results indicate that PCR is a sensitive and rapid technique for the diagnosis of EHV‐1 and EHV‐4 infection.
The effects of stress on gastric ulceration, T3, T4, reverse T3 and Cortisol in neonatal foals
Authors: FURR M. O. , MURRAY M. J. , FERGUSON D. C.
Published: April 2010

Sixteen neonatal foals stressed by disease underwent endoscopic examination of their stomachs and blood was assayed for triiodothyronine (T3), reverse T3 (rT3), thyroxine (T4) and Cortisol, to determine the effects of severe physiological stress and the occurrence of gastric ulcers, compared with eight age‐matched controls, six foals had abnormal Cortisol, seven had abnormal T3 and 12 had abnormal T4. Eleven of 13 foals had rT3 outside the 95 per cent confidence interval for clinically normal foals of comparable ages. Gastric lesions were seen more frequently in stressed foals, and gastric glandular mucosal lesions were noted in 40 per cent of the stressed foals. Previous studies report low (3 per cent) occurrence of gastric mucosal lesions. The frequency of squamous mucosal lesions was not different from that reported previously, indicating that stress has little effect on the development of lesions at this site.
Total carnitine content of the middle gluteal muscle of Thoroughbred horses: normal values, variability and effect of acute exercise
Authors: FOSTER C. V. LOUISE , HARRIS R. C.
Published: April 2010

There was no detectable loss of total carnitine associated with intense exercise from the middle gluteal muscle of Thoroughbred horses. Measurements made on a single biopsy obtained during the course of a normal training and exercise programme may, therefore, be considered representative of the normal content at rest. The variability in total carnitine content within the normal muscle biopsy area amounted to 13.2 per cent of the normal mean content. Approximately 50 per cent of this variability could be attributed to covariation with citrate synthase, to which it was highly significantly correlated. The muscle carnitine content of yearling Thoroughbred horses ranged from 10.5 to 18.8 mmol/kg dry muscle (dm); the ranges in untrained, lightly trained and fully trained two‐year‐olds were 18.5 to 34.7, 14.1 to 24.2 and 22.9 to 26.9 mmol/kg dm, respectively. In horses aged over three years total carnitine ranged from 21.3 to 35.5 mmol/kg dm. A trend toward higher contents of total carnitine with age and training appeared to be largely a consequence of underlying changes in mitochondria density as indicated by differences in levels of citrate synthase activity. There was a marked difference in ratios of total carnitine to citrate synthase activity between training yards, reflecting possible differences in management regimes and/or bloodstock selection.
Atresia coli in the foal: a review of six cases
Authors: YOUNG R. L. , LINFORD R. L. , OLANDER H. J.
Published: April 2010

Physical examination and exploratory celiotomy were performed on five neonatal foals presented with signs of acute colic. Atresia coli was confirmed in each foal during surgery. The most consistent finding on physical examination was the absence of meconium staining following repeated enemas. The large, transverse and/or small colon were involved in all foals. One eight month aborted foetus was submitted for necropsy and diagnosed as having atresia coli and congenital hydrocephalus. Atresia coli should be considered for neonatal foals with signs of acute colic.
Ileal intussusception in 16 young Thoroughbreds
Authors: GREET T. R. C.
Published: April 2010

The paper describes the outcome of 16 cases of short ileal‐ileal intussusception in young Thoroughbred horses. The intussusception was often associated with chronic or intermittent low grade abdominal pain. At laparotomy, only the intussusception was reduced in one horse; in another, a myotomy of the thickened stenosed intussusception was carried out after reduction. In 11 cases an ileocaecal bypass anastomosis was performed proximal to the intussusception after its reduction. One horse was subjected to euthanasia during operation because of irreversible intestinal wall damage and another because of intestinal rupture. One foal had a cardiac arrest following reduction of the intussusception. One horse was subjected to euthanasia 4 months post‐operatively because of intractable abdominal pain caused by intestinal adhesions. Although several horses suffered episodes of postoperative abdominal pain, and 2 were subjected to a second laparotomy, 12 horses made an eventual complete recovery.
A two year, prospective survey of equine colic in general practice
Authors: PROUDMAN C. J.
Published: April 2010

The records of 200 colic episodes, collected prospectively, over a two year period, from first opinion cases, were analysed and compared with a control sample selected at random from the same population. Analysis by colic type revealed 72% spasmodic/undiagnosed; 7% surgical; 5.5% flatulent; 5% pelvic flexure impactions; 9.5% other impactions and 1% colitis. A possible predisposing cause was identified in 43% of the spasmodic/undiagnosed cases. The total incidence of colic in each age group showed no statistically significant differences from the control population. Stallions were significantly under represented in the colic population. When compared with the control sample the number of spasmodic/undiagnosed colic cases in the 5–10‐year‐old group and the number of surgical colics in the over 15‐year‐old group were significantly greater than expected. No statistically significant correlation was found when the seasonal incidence of colic was compared with monthly temperature, change in monthly temperature, monthly rainfall, and rainfall weighted for temperature.
On the genetic basis of equine allergic diseases: II. Insect bite dermal hypersensitivity
Authors: MARTI ELIANE , GERBER H. , LAZARY S.
Published: April 2010

The horses studied were of the Swiss Warmblood breed and most were ELA‐typed to assess a possible association of dermal hypersensitivy to insect bites with the major histocompatibility complex.

Firstly, the occurrence of the condition was examined in 304 half‐siblings sired by six stallions (A to F). Fourteen cases of dermal hypersensitivity were recognized and all were in the 153 offspring of Stallions C, E and F. Most animals of this group were also investigated for chronic hypersensitivity bronchitis: none of the sires displayed clinical signs of dermal hypersensitivity, but Stallions D, E and F were affected by chronic bronchitis. Among the animals investigated for both conditions only one horse showed coincidence of the two diseases as can be expected when the diseases are not correlated. The frequency of manifest dermal hypersensitivity and/or chronic hypersensitivity bronchitis varied in the half‐sibling groups of individual sires. These findings suggest that the allergic conditions are independent entities.

Secondly, the occurrence of dermal hypersensitivity was studied in three generations of horses at a stud at which Stallion C had exerted a particularly strong influence. A total of 302 animals, all born and raised at this stud, were surveyed over a period of 12 years. The descendants of Stallion C showed a significantly higher incidence (P<0.01) of dermal hypersensitivity (two daughters out of 19; eight second generation offspring out of 103; one third generation offspring out of 85) than did the controls of the same age classes but unrelated to Stallion C at the same stud (0 out of 95). In this group the predisposition was not associated with the ELA antigens of Stallion C.

Thirdly, the pedigrees and the ELA‐haplotypes of eight affected half‐siblings by Stallion F were studied more closely. The predisposition in these horses was associated with the paternal haplotype A3,W23. Four multiple‐case families were studied separately. One sire (G) produced nine affected offspring out of 22 out of four clinically healthy dams. The dams, however, were descendants from Stallion C and they produced four unaffected foals by other sires. The paternal ELA‐haplotype, A15,W23, segregated (with one exception) coupled with the predisposition to the affection. Stallion G and the dams were born, raised and kept at the same stud as their offspring.

Based on these findings, we suggest that certain animals can transfer hereditary susceptibility for dermal hypersensitivity due to insect bites to their offspring. In different families the ELA class II specificity W23 segregated with the susceptibility. A gene or genes of the major histocompatibility complex appeared to play a role in some families as well as a gene or genes outside the MHC. Therefore we suggest that insect bite dermal hypersensitivity is a multifactorial disease, including hereditary and environmental factors in its pathogenesis.
Plasma elimination and urinary excretion of procaine after administration of different products to Standardbred mares
Authors: STEVENSON ADRIENNE J. , WEBER M. P. , TODI F. , YOUNG L. , BEAUMIER P. , KACEW S.
Published: April 2010

Plasma and urinary concentrations of procaine were examined in Standardbred mares after subcutaneous administration of various doses (80 mg to 1600 mg) of procaine hydrochloride. Regardless of dose, peak plasma procaine values occurred within 1 h, but remained detectable in a dose‐dependent manner, with procaine present at 1 h with the 80 mg dose and 6 h at the 1600 mg dose. Similarly, peak urinary procaine concentrations were attained within 1.5 to 3 h, irrespective of dose, while detection time was dose‐dependent, being 23 h for 80–200 mg doses but as long as 30–54 h with the 1600 mg dose. When mares were given a single intramuscular injection of a penicillin G‐procaine preparation (Ethacillin, Cillimycin, Penamycin, Derapen A, Azimycin or Diathal), peak plasma procaine concentrations varied and were reached from 10 min to 3 h in all cases, with detection from 3 to 20 h after drug administration. Although the peak urinary levels of procaine occurred between 30 mins and 6 h, detection in urine in most cases was as long as 78–120 h except for Diathal for which detection was limited to 54 h. Daily administration of a penicillin G‐procaine preparation (Pen‐Di‐Strep) for 5 days produced a biphasic peak in plasma procaine at 3 and at 6–9 h with detection from 16 to 23 h after drug treatment. Although peak urinary procaine values were reached at similar times after single or multiple injections, the duration of detection was markedly longer (425 h) after the multiple‐dose regimen. Plasma procaine concentrations could not be detected after topical (Special Formula 17900) or oral (Pro‐Pen Feed Mix) penicillin G‐procaine administration but procaine was detected in urine at 30 h with the topical and at 54 h with the oral treatment.
Constrictive pericarditis in a mare: attempted treatment by partial pericardiectomy
Authors: HARDY JOANNE , ROBERTSON J. T. , REED S. M.
Published: April 2010

Chronic constrictive pericarditis was diagnosed in a 6‐year‐old Thoroughbred mare based on the clinical findings of right congestive heart failure, hyperechoic pericardium without pericardial effusion, and a dip‐and‐plateau shape of the right ventricular pressure curve with equilibration of the diastolic pressures in all cardiac chambers. Treatment was attempted by partial pericardiectomy using a right lateral thoracotomy approach. Because of severe epicardial involvement recurrence of the constrictive pathology was noted 6 weeks after the surgical procedure. However, in selected cases in which the disease process is limited to the pericardium, partial pericardiectomy may offer a mode of therapy in horses suffering from constrictive pericarditis.
A field study of patterns of unobserved foetal loss as determined by rectal palpation in foaling, barren and maiden Thoroughbred mares
Authors: GILBERT R. O. , MARLOW C. H. B.
Published: April 2010

Records of 1,009 pregnancies in 574 foaling, barren and maiden Thoroughbred mares on a single stud farm, over a period of 12 years were examined. The farm is situated in the eastern Cape Province of South Africa, at an elevation of 1,800 m, and in an area of climatic extremes. Records of 604 pregnancies in 249 foaling Thoroughbred mares were examined. For these purposes, those pregnancies in which a mare conceived in the same breeding season during which she had foaled were considered as pregnancies in foaling mares. Pregnancy was confirmed by rectal palpation by a single experienced practitioner. Of the 604 pregnancies examined, conceptus attachment occurred in the horn opposite the previously gravid horn in 345 cases (57%), and in the previously gravid horn in 259 cases (43%; P < 0.005). Unobserved foetal loss after pregnancy diagnosis amounted to 30 (9%) in the former group, while in the latter group (pregnancy established in the postgravid horn) 46 pregnancies were lost (18%; P< 0.005). This study confirmed that conceptus attachment tends to occur in the uterine horn opposite the previously gravid horn in foaling Thoroughbred mares conceiving during the same season. A significantly higher incidence of foetal loss accompanied conceptus attachment in the postgravid horn.

Of 242 pregnancies in 162 previously barren mares, 95 (39%) occurred in the left uterine horn and 147 (61%) in the right horn (P < 0.005). The incidence of pregnancy failure in this group was 7%. The side of attachment did not affect the rate of loss. Evaluation of the records of 163 maiden mares revealed that conceptus attachment occurred in the left uterine horn in 58 (36%) pregnancies and in the right horn in 105 (64%) pregnancies (P< 0.005), which is consistent with previously reported observations. Pregnancy failure was recorded in 4% of maiden mares. Side of attachment did not influence rate of loss in this group.
Ultrasound speed in the metacarpal cortex — a survey of 347 Thoroughbreds in training
Authors: BUCKINGHAM S. H. W. , McCARTHY R. N. , ANDERSON G. A. , McCARTNEY R. N. , JEFFCOTT L. B.
Published: April 2010

Transmission ultrasound speed was determined in the third metacarpal bone of 347 Thoroughbred racehorses in training. In addition to direct measurement of apparent ultrasound speed and lateral bone diameter, several derived parameters were estimated (cortical ultrasound speed, corticomedullary ratio and cortical cross‐sectional area). Multiple regression equations were developed for each ultrasound measurement using the explanatory variables: sex, age, duration and intensity of training, preparation number and previous shin soreness. The horses (114 females, 82 entire males and 151 geldings ranging in age from 20 to 116 months) had been in continuous training for an average of 10.0 weeks when measurements were made. All measurements except corticomedullary ratio were influenced by the sex of the horse. Geldings had significantly lower ultrasound transmission speed than entire males and females, reflecting a lower bone density. However, the geldings had larger cross‐sectional areas (ie bone size). We suggest that the relationship between low ultrasound speed (ie low bone density) and large cross‐sectional area maintains the overall mechanical integrity of the metacarpus. This relationship (high ultrasound speed and low cross‐sectional area) was also found in each sex group. Ultrasound speed and corticomedullary ratio, but not cross‐sectional area, were affected by age. Both duration and intensity of training influenced the ultrasound speed measurements. This study indicated that sex, age and state of training affect ultrasound results, but this explained only about 30% of the variance in the data. Other factors, ie genetic variation in bone density and size, differences in soft tissue thickness and distal limb temperature, presumably account for most of the variance.

Acknowledgements. This project was sponsored by the Australian Equine Research Foundation and partly through a special grant from the Department of Sport and Recreation of Victoria. We thank Dr C. Savage and Dr H. Davies for assistance and advice; Mrs M. Jones and Mr A. Alder for technical help with the ultrasound measurements; and the many trainers who allowed access to the horses in their care.
Pulmonary artery and aortic pressure changes during high intensity treadmill exercise in the horse: effect of frusemide and phentolamine
Authors: ERICKSON B. K. , ERICKSON H. H. , COFFMAN J. R.
Published: April 2010

Intravenous frusemide (1.0 mg/kg bwt) or phentolamine (0.33 mg/kg bwt) was given to 7 horses 1 h before exercise and their effects on pulmonary artery and aortic pressure changes during strenuous exercise were examined. Short‐term near‐maximal treadmill exercise (10 m/sec, 3° incline) produced increases in heart rate, mean pulmonary artery pressure (PAP), mean aortic pressure (AP), and packed cell volume (PCV). Frusemide did not affect heart rate, PAP or PCV during exercise. Frusemide significantly decreased mean AP by 10 to 15 mmHg during exercise. Phentolamine produced an increase in heart rate relative to control only early in exercise but not during later, more strenuous, exercise. Phentolamine had no statistically significant effect on AP, PAP or PCV, but a significant reduction was observed between 180 and 230 sec of exercise when PAP and AP were standardised against heart rate. Frusemide did not prevent horses from haemorrhaging during exercise in this study. Treatment with phentolamine did not sufficiently reduce the PAP and AP to test our hypothesis that a reduction in PAP and AP would eliminate EIPH.
Abortion of virologically negative foetuses following experimental challenge of pregnant pony mares with Equid herpesvirus 1
Authors: SMITH K. C. , WHITWELL KATHERINE E. , BINNS M. M. , DOLBY CHRISTINE A. , HANNANT D. , MUMFORD JENNY A.
Published: April 2010

From 1988 to 1991, 51 pregnant pony mares were challenged intranasally or by aerosol with an isolate of EHV‐1 (AB4) originally recovered from a quadriplegic mare. This resulted in 32 abortions, occurring from 9 to 29 days after infection. In 14 of the early abortions (Days 9–14), EHV‐1 was not demonstrated in the foetal tissues by virus isolation or immunostaining despite no other non‐viral cause for the abortion being evident. Application of the polymerase chain reaction to foetal tissues from 9 of these cases also proved negative. One of the 14 mares was destroyed immediately after abortion, and post‐mortem examination revealed severe and widespread vasculitis, thrombosis and secondary ischaemic damage in the endometrium with replication of EHV‐1 in endothelial cells. These findings suggest that EHV‐1 abortion can occur due to endometrial damage without the establishment of a foetal infection.
Skeletal muscle characteristics in young trained and untrained Standardbred trotters
Authors: RONÉUS MERIKE , ESSÉN‐GUSTAVSSON BIRGITTA , LINDHOLM A. , PERSSON S. G. B.
Published: April 2010

Muscle biopsies were taken from the middle gluteal muscle of 28 Standardbred trotters, 3–4 years of age. The 13 horses in Group T were trained consistently from 18 months of age, whereas the 15 horses in Group UT were not exposed to any systematic training before 3 years of age. Group T horses had a lower percentage of Type IIB fibres (31%) than did Group UT horses (39%). Citrate synthase (CS) activity, representing oxidative capacity, was higher in Group T (72 mmol kg−1min−1) than in Group UT (47 mmol kg−1min−1). Biopsies were taken from 4 horses in each group when they were foals and then annually until 3–4 years of age. Results from this study indicate that regular training of Standardbreds from 18 months of age resulted in increased CS activity and a decrease in the percentage of Type IIB fibres. This study shows that training, not growth, is the main factor that induces a high oxidative capacity and a high Type IIA/IIB fibre ratio in muscle of Standardbred trotters.
Five cases of gastrocnemius tendinitis in the horse
Authors: DYSON SUE J. , KIDD LISA
Published: April 2010

The normal gastrocnemius tendon may contain some muscular tissue proximally. This results in a patchy echogenicity ultrasonographically where it lies caudal or lateral to the superficial digital flexor tendon (SDFT). When it has assumed a position dorsal (cranial) to the SDFT the gastrocnemius tendon has a more uniform echogenicity and its margins are well defined. Five horses had lameness associated with lesions identified ultrasonographically in the gastrocnemius tendon in the latter region. Lameness ranged from mild to severe and was characterised by reduced hock flexion, lowered arc of foot flight, shortened length of the cranial phase of the stride and in some horses a reduced duration of weight bearing during the caudal phase of the stride. Lameness was variably accentuated by flexion of the proximal or distal limb joints of the lame limb. Perineural analgesia of the tibial and fibular nerves or the tibial nerve alone substantially improved the lameness. All horses remained lame 2–3 months after initial examination, with minimal change in the ultrasonographic appearance of the lesion(s).
Retrospective study of 38 cases of femur fractures in horses less than one year of age
Authors: HANCE S. R. , BRAMLAGE L. R. , SCHNEIDER R.K. , EMBERTSON R. M.
Published: April 2010

Medical records of 38 horses <1 year of age and diagnosed as having a fracture of the femoral diaphysis, metaphysis or distal physis were evaluated. Twenty‐six foals had fractures of the femoral diaphysis or metaphysis with the most common fracture configuration being comminuted. Twelve foals had distal physeal fractures with the most common fracture configuration being a Salter‐Harris type II. Twenty‐one foals with fractures of the capital femoral physis, neck or greater trochanter during the same time period were excluded from this study. Surgical repair was attempted in 16 diaphyseal and 2 distal physeal fractures. Most of the diaphyseal fractures were repaired by placing plates on the lateral and cranial surfaces of the bone. Dynamic condylar screw plates or angle blade plates were used for increased bone purchase in 4 foals with short distal fragments. Five foals with distal physeal fractures were treated; 2 were surgically treated by placing an angle blade plate on the lateral cortex, and 3 foals with minimally displaced distal physeal fractures were managed with stall confinement. Eight of the 16 surgically repaired diaphyseal fractures healed. Fracture location and configuration was not a determinant of outcome, but the mean age of foals with successfully repaired diaphyseal fractures was 2 months compared with 4 months for the unsuccessful cases, indicating that the age and size of the foal was important. Long‐term follow up revealed that 6 of the 8 successfully repaired diaphyseal fractures had no residual effects of the fracture observed during performance of the horse for its intended use. Only 1 of the 2 surgically repaired distal physeal fractures healed, but this horse was eventually killed because of unthriftiness related to a malabsorption syndrome. Some form of complication developed in 13 of the 18 surgically repaired fractures. Infection was the primary cause of failure. The greatest determinant associated with infection was the inability to control post‐surgical seroma formation.
Arachidonate metabolites in bronchoalveolar lavage fluid from horses with and without COPD
Authors: WATSON ELAINE D. , SWEENEY C. R. , STEENSMA K. A.
Published: April 2010

Arachidonate metabolites were measured in bronchoalveolar lavage fluid (BALF) from horses with (N = 4) and without (N = 7) chronic obstructive pulmonary disease (COPD). Prostaglandin (PG) D2, leukotriene (LT) B4and LTC4were present in highest concentrations in BALF from clinically normal horses. Concentrations of PGE2and PGF were significantly higher in BALF from horses with COPD than in BALF from normal horses, but no differences were detected in thromboxane B2, 6‐keto‐PGF1α, PGD2, LTB4or LTC4.