Efficacy of thermal cautery for intermittent dorsal displacement of the soft palate as compared to conservatively treated horses: results from 78 treadmill diagnosed horses.

REASONS FOR PERFORMING STUDY: Previously, objective comparisons of surgical procedures to relieve dorsal displacement of the soft palate (DDSP) have been limited by the presumptive basis of the diagnostic measures applied. OBJECTIVES: To assess and compare the efficacy of thermal cautery surgery to conservatively treated controls in racehorses definitively diagnosed with idiopathic intermittent DDSP. HYPOTHESIS: Both conservative and surgical treatments have a beneficial result on racing performance in racehorses affected with DDSP. METHODS: Race records were obtained for Thoroughbred racehorses definitively diagnosed with DDSP using high-speed treadmill endoscopy. Racing performance was assessed based on prize money won. RESULTS: Forty-eight horses that underwent thermal cautery and 30 conservatively treated controls were included. Pretreatment earnings significantly decreased in the race immediately prior to diagnosis. A high proportion of previously raced horses returned to racing after both treatments (90-96%). Intrahorse comparison of earnings in 3 races pre- vs. post treatment showed that 53% of conservatively treated horses and 36% of the thermal cautery group had improved performance. Although the difference between these 2 groups may be interpreted as being clinically significant, it was not statistically significant. CONCLUSIONS AND POTENTIAL RELEVANCE: A higher percentage of conservatively treated controls had improved individual performance compared to horses treated with thermal cautery. Thermal cautery appears less effective than other previously published surgical treatments for DDSP. Comparison of the 2 treatment methods should be interpreted cautiously because treatments were not randomised, resulting in baseline variability between groups.

Use of tongue ties in thoroughbred racehorses in the United Kingdom, and its association with surgery for dorsal displacement of the soft palate.

The prevalence of the use of tongue ties, calculated from 60 randomly selected race meetings held in the UK during 2001 to 2003, was 5.0 per cent. After its first use on an individual horse a tongue tie was used in an average of 77 per cent of its races during the first 12 months, but after this time period, in only 55 per cent of its races. Thirty-nine per cent of horses that underwent surgery for dorsal displacement of the soft palate raced with a tongue tie preoperatively, and 41 per cent of these surgical cases raced with a tongue tie postoperatively.

Gastric and small intestinal ileus as a cause of acute colic in the post parturient mare.

REASONS FOR PERFORMING STUDY: Ileus (functional obstruction of aboral gastrointestinal transit) is an uncommon cause of gastrointestinal dysfunction and colic in the horse. A number of specific conditions have been previously reported in association with ileus. This report describes the recognition of primary gastric and small intestinal ileus of undetermined cause in a series of post parturient mares. OBJECTIVES: To describe the clinical features, treatment and outcome of a series of episodes of primary gastric and small intestinal ileus. METHODS: A retrospective study was performed of colic episodes seen in an equine practice in Newmarket, UK over a 6 year period (2002-2007). RESULTS: Seventeen episodes of gastric and small intestinal ileus were identified, which occurred in 15 horses. All episodes occurred in post parturient mares. No previously reported cause of ileus was identified in any of the episodes. Fifteen of the 17 episodes received medical treatment (medical support and nasogastric decompression) and, in addition, surgical decompression was performed in 9 episodes. Two mares were subjected to euthanasia before treatment due to the presence of gastric rupture and the remaining 13 mares survived with a follow-up period of at least 10 months. Two mares suffered a further episode of gastric and small intestinal ileus, one 4 days and the other 2 years after the initial episode. CONCLUSIONS: Gastric and small intestinal ileus of, as yet, unknown aetiology appears to be a potential cause of acute colic in the post parturient mare. The outcome following treatment by decompression is good.

Laparoscopic application of PGE2 to re-establish oviducal patency and fertility in infertile mares: a preliminary study.

REASONS FOR PERFORMING STUDY: Mares are occasionally encountered that consistently fail to conceive when inseminated, naturally or artificially, with fertile stallion semen in the absence of any identifiable pathology of either the structure or function of their reproductive tract. HYPOTHESIS: Temporary blockage of the oviducts by accumulations of naturally occurring oviducal masses may be preventing oviducal transport of the embryo to the uterus. METHODS: Mares, with known reproductive histories, that had exhibited inexplicable failure of conception were treated by laparoscopically guided administration of PGE2-laced triacetin gel directly onto the surface of their oviducts. RESULTS: Fifteen mares age 10-21 years that had exhibited inexplicable failure of conception during 1-4 years were treated, of which 14 (93%) conceived within the same or subsequent breeding season. CONCLUSIONS: The high success rate of this treatment supports the tentative diagnosis of oviducal obstruction in these mares and indicates that blockage of the mare's oviducts may occur in the form of a moveable accumulation of debris rather than from permanent fibrous adhesions resulting from salpingitis. POTENTIAL RELEVANCE: This laparoscopic application of PGE2 to the oviducts constitutes a sound and practical method of restoring fertility in mares suffering oviducal obstruction and further studies involving the procedure are warranted.

Chronic colic in the mature horse: a retrospective review of 106 cases.

The clinical features of 106 horses presenting with chronic colic examined over a 5 year period were reviewed. Chronic colic was defined as colic signs observed daily for 3 days or longer, except when masked by analgesics. The diagnosed causes of chronic colic included colonic impaction (31%), peritonitis (16%), enteritis/colitis (7%), colonic displacement/torsion (6%) and lymphosarcoma (4%). A variety of other diseases were diagnosed in a small number of cases, including intestinal adhesions, ileal obstructions, grass sickness, liver disease, caecal impactions, thromboembolic disease, intussusceptions etc. No diagnosis was reached in 8% of cases. Diagnosis was relatively easily achieved in most cases of colonic impaction and peritonitis by results of transrectal palpation and evaluation of peritoneal fluid. Specific clinical features, transrectal palpation, abdominal paracentesis and laboratory evaluations of blood were helpful in the diagnosis of some of the other diseases, but exploratory laparotomy remained necessary in a few cases to achieve a diagnosis.

Recurrent colic in the mature horse: a retrospective review of 58 cases.

The clinical features of 58 horses presenting with recurrent colic examined over a 5 year period were reviewed. The horses were categorised into 3 groups on the basis of the history of colic episodes. Recurrent transient colic Group 1 was characterised by 3 or more episodes of transient colic (of apparently similar type) occurring within one month. Recurrent transient colic Group 2 was characterised by 3 or more episodes of transient colic occurring within one year. Recurrent prolonged colic was characterised by 3 or more episodes of prolonged colic occurring within one year. Fifteen horses were classified as recurrent transient colic Group 1. This group had the highest mortality rate 53%. They included 3 horses with lymphosarcoma, 2 with intussusceptions, 2 with thromboembolic disease/verminous arteritis and 2 with partial ileal obstructions. The recurrent transient colic Group 2 comprised 27 cases with a mortality rate of 4%. Nine of these horses were affected by spasmodic colic. The recurrent prolonged group involved 16 horses with a mortality rate of 31%. These included 3 cases of recurrent colonic impaction and 2 cases each of lymphosarcoma, 2 thromboembolic disease, 2 partial ileal obstructions and 2 intestinal adhesions.

Epidemiological risk factors associated with a diagnosis of clinical cyathostomiasis in the horse.

Multiple logistic regression was used to assess epidemiological risk factors associated with the diagnosis of cyathostomiasis in 87 cases of chronic diarrhoea in the horse. Age, season and the period since last receiving anthelmintics were identified as important risk factors using chi-square and two-sample t test analyses, whereas access to grazing, shared grazing with other horses and recurrence of signs were only weakly associated with a diagnosis of cyathostomiasis. Multivariate analysis of the parameters using logistic regression was performed. The final model included age, season and time since last deworming. At a predicted probability of cyathostomiasis of 0.5, the model had a specificity of 86.0%, sensitivity of 66.7%, overall correct classification of 79.3%, a positive predictive value of 71.4% and a negative predictive value of 83.1%. The results of this study indicated that the specified variables and factors may be useful in the differentiation of clinical cyathostomiasis from other causes of chronic diarrhoea, based on case history alone.

A cross-sectional study of colic in horses on thoroughbred training premises in the British Isles in 1997.

The aim of this study was to estimate the incidence of colic in horses in Thoroughbred training premises in 1997 in the British Isles. The seasonal pattern and outcome of colic episodes were also investigated, together with any association between premises level variables and colic. Data were collected by a postal questionnaire. The results showed a colic incidence density of 7.19/100 horse years (s.e. 0.42) and a cumulative incidence of colic of 5.80% (s.e. 0.30). Premises were grouped according to whether they had more Flat than National Hunt horses (Flat premises) or more National Hunt than Flat horses (NH premises). A similar rate of colic episodes was found in each group. However, significantly higher cumulative incidences of one episode of colic were found in the Flat premises and of multiple episodes in the NH premises, respectively. The outcome of each episode of colic showed spontaneous recovery in 28.7%, medical recovery in 63.1%, surgical recovery in 2.0% and death in 6.2% of cases. This indicated an overall mortality rate from colic of 0.45 deaths/100 horse years. The seasonal pattern of episodes of colic showed a spring and autumn peak, with significant differences in the seasonal pattern between the Flat and NH premises. Relative risk analysis and logistic regression modelling with random effects showed significant associations between the number of episodes of colic and the number of horses on the premises (allowing for the number of horses on each premises, the larger premises had a decreased risk of colic). After adjusting for the number of horses, 3 other variables were associated with colic; Flat premises (with an increased risk), the owner being the sole person looking after the horses (a decreased risk) and the premises being a combined training and breeding establishment (a decreased risk).

Small intestinal malabsorption in the horse: an assessment of the specificity of the oral glucose tolerance test.

Specificity of the oral glucose tolerance test (OGTT) for the diagnosis of small intestinal malabsorption in the horse was assessed by comparing the results of OGTT with the results of a histopathological examination of the small intestine in 42 adult horses affected by chronic weight loss. The horses were assigned to three groups on the basis of the results of the test. Five horses were considered to have a normal OGTT absorption result (Group 1); all the horses had a histologically normal small intestine. Twenty-five horses had a partial malabsorption result (Group 2) seven of which had normal small intestinal morphology, whereas the remaining 18 had a variety of pathological lesions including lymphosarcoma, villous atrophy, granulomatous enteritis and eosinophilic gastroenteritis. Twelve of the 42 horses had a total malabsorption result (Group 3), and all had a severe infiltrative lesion in the small intestinal wall (either lymphosarcoma or granulomatous enteritis).

Case control study to identify risk factors for simple colonic obstruction and distension colic in horses.

A case control study was performed to identify risk factors for colic caused by simple colonic obstruction and distension (SCOD) in the horse. Case horses were recruited from 2 veterinary school clinics. Control horses were population based and matched by time of year. A number of risk factors were considered in the following areas: general carer and premises information; exercise information; husbandry information (housing- and pasture-related); feeding information; breeding information; behavioural information; travel information; preventive medicine information and previous medical information. All variables with a P value of <0.2 in the univariable analysis were considered for possible inclusion in a multivariable model. A final model, produced by a forward stepwise method, identified crib-biting or windsucking, an increasing number of hours spent in a stable, a recent change in a regular exercise programme, the absence of administration of an ivermectin or moxidectin anthelmintic in the previous 12 months and a history of travel in the previous 24 h as associated with a significantly increased risk of SCOD. An alternative final model, produced by a backwards elimination method, identified the same variables as the forward model with, in addition, a history of residing on the current establishment for less than 6 months, a history of a previous colic episode and the fewer times per year the teeth were checked/treated as associated with a significantly increased risk of SCOD. Three of the risk factors in this model were associated with a large increase in risk: stabling for 24 h/day, crib-biting/windsucking and travel in the previous 24 h.

Development and application of a scoring system for prognostic evaluation of equine liver biopsies.

REASONS FOR PERFORMING STUDY: The study was designed to investigate the prognostic value of liver biopsy during investigation of cases of suspected liver disease in mature horses. HYPOTHESIS: That liver biopsy is the most prognostically useful technique in common usage in the investigation of suspected liver disease. METHODS: This study examined the prognostic value of liver biopsy during the investigation of suspected liver disease in 73 mature horses. Histopathological variables comprising fibrosis, irreversible cytopathology, inflammatory infiltration, haemosiderin accumulation and biliary hyperplasia were found to be significant predictors of nonsurvival and were used to formulate a weighted biopsy score representing a prognostically useful broad comparative index of histopathological severity. Minimum and maximum possible scores were 0 and 14 points, respectively. RESULTS: Retrospective application of the biopsy scoring system to the study population indicated that horses with scores of 0 or 1 were equally likely to survive to 6 months with a combined mortality of 4%. Horses with biopsy scores between 2 and 6 had a combined mortality of 33% and were at a 12-fold increased risk of nonsurvival within 6 months (hazard ratio = 12.04, 95% CI 134-107.81, P = 0.026) compared to horses with a biopsy score of 0. Horses with biopsy scores between 7 and 14 had a combined mortality of 86% and were at a 46-fold increased risk of nonsurvival (hazard ratio = 46.01, 95% CI 5.92-357.5, P < 0.001) compared to horses with biopsy score 0. CONCLUSIONS: Application of the biopsy scoring system to histopathological findings in liver biopsy specimens was very useful in predicting survival of cases of suspected liver disease. POTENTIAL RELEVANCE: Application of the findings in this study may not be directly applicable to other case populations. However, liver biopsy appears to be the most valuable prognostic technique employed during the investigation of suspected cases of liver disease in mature horses.

Retrospective analysis of historical, clinical, ultrasonographic, serum biochemical and haematological data in prognostic evaluation of equine liver disease.

REASONS FOR PERFORMING STUDY: Results of noninvasive tests of liver disease do not always correlate with the degree of hepatic disease nor outcome of the case. OBJECTIVE: To investigate the prognostic value of data collected using noninvasive tests during the investigation of cases of suspected liver disease in mature horses. HYPOTHESIS: Much of the data gathered during the investigation of suspected hepatopathy cases offers little prognostic guidance and interpretation of such data can be misleading. METHODS: The results from a range of common and noninvasive diagnostic techniques applied in 116 mature horses with suspected liver disease, were assessed for their ability to predict survival within a 6 month period. RESULTS: A significantly poorer prognosis was found in association with clinical signs suggestive of liver disease, presence of hepatic encephalopathy, ultrasonographic abnormalities, increased serum globulins, increased total bile acids (TBA), increased alkaline phosphatase (AP), increased gamma-glutamyl transferase (gammaGT), erythrocytosis, leucocytosis, low serum albumin and low serum urea. Additional significant novel findings of interest included an association between increased plasma fibrinogen and low serum creatinine concentrations with nonsurvival in cases of liver disease, an association between raised serum concentrations of AP and gammaGT with biliary hyperplasia and also an association between hepatic fibrosis, haemosiderosis and biliary hyperplasia with ultrasonographically detected hepatic abnormalities. CONCLUSIONS: The most useful noninvasive prognostic test in cases of suspected liver disease in mature horses is the severity of clinical signs. Other data may be of some limited prognostic value. POTENTIAL RELEVANCE: Application of the findings in this study may not be directly applicable to other case populations. However, the findings should at least be considered when prognosis is based on similar criteria.

Endoscopic surgery in the treatment of contaminated and infected synovial cavities.

REASONS FOR PERFORMING STUDY: Contamination and infection of synovial cavities are a common occurrence in clinical practice and, if inadequately treated, may have career or life threatening consequences for affected horses. HYPOTHESIS: The objectives in treating contamination and infection of joints, tendon sheaths and bursae are most effectively met by endoscopic surgery. METHODS: Over a 6 year period, cases of synovial contamination and infection admitted to a referral clinic were evaluated and treated endoscopically. The horses received local and systemic antimicrobial drugs with minimal nonsteroidal anti-inflammatory medication but no other medical or surgical treatment. All arthroscope and instrument portals and, whenever possible, all traumatic wounds were closed. Diagnostic information, endoscopic observations and results of treatment were evaluated retrospectively. RESULTS: A total of 140 affected animals were referred and 121 cases were treated endoscopically. These involved 70 joints, 29 tendon sheaths, 10 bursae and in 12 cases a combination of synovial cavities. The most common aetiologies were open wounds (n = 54) and self-sealing punctures (n = 41). Foreign material was identified endoscopically in 41 but predicted prior to surgery in only 6 cases. Osteochondral lesions were evident at surgery in 51 and recognised before surgery in 25 cases; 32 horses had intrathecal tendon or ligament defects. Follow-up information was obtained for 118 animals; 106 (90%) survived and 96 (81%) returned to their preoperative level of performance. The presence of osteitis/osteomyelitis, other osteochondral lesions and marked deposits of pannus were associated with nonsurvival. For those animals which survived, non-Thoroughbred horses, a combination of synovial structure involvement and regional i.v. antimicrobial administration were associated with reduced post operative performance. Marked pannus, regional i.v. antimicrobial administration and duration of systemic antimicrobial administration were associated with a group combining nonsurviving animals and those with reduced post operative performance. CONCLUSIONS: Endoscopic surgery makes a valuable contribution to the management of synovial contamination and infection. POTENTIAL RELEVANCE: The information obtained from and therapeutic options offered by endoscopy justify its early use in cases of synovial contamination and infection.

Hypertrophic osteopathy (Marie's disease) in Equidae: a review of twenty-four cases.

The case records of 23 horses and one donkey affected by hypertrophic osteopathy (HO) (Marie's disease) were reviewed. All affected animals presented with limb swellings, which were bilaterally symmetrical and usually involved both fore- and hindlimbs. Associated signs included stiffness/lameness and weight loss. Radiological features included periosteal new bone formation over the diaphyses and metaphyses of affected bones. The metacarpal and metatarsal bones were most frequently affected. Articular surfaces remained free of disease. Seventeen animals were destroyed on humane grounds, 3 horses recovered after successful treatment of the primary disease, 3 horses recovered after symptomatic treatment and one horse was lost to follow-up. Significant primary diseases that were believed to predispose to HO were identified (pre- or post mortem) in 14 cases. In each of these cases, an intrathoracic disease was identified, although co-existing extrathoracic disease was present in 3 cases. Granulomatous inflammatory lesions were present in 9 of these 14 cases. In 4 horses, which underwent necropsy examination, no significant underlying disease was identified.

Multisystemic eosinophilic epitheliotropic disease in a horse: attempted treatment with hydroxyurea and dexamethasone.

Equine multisystemic eosinophilic epitheliotropic disease is rare in horses. The clinical signs vary according to the organs affected, the skin and gastrointestinal tract being most commonly involved. This paper gives the first reported description of a horse with multisystemic eosinophilic epitheliotropic disease in the United Kingdom and the attempts to treat it. The horse showed dermatological, gastrointestinal, hepatic, pulmonary and pancreatic involvement. Some improvement was seen when the horse was treated with corticosteroid and hydroxyurea.

Chronic diarrhoea in adult horses: a review of 51 referred cases.

A retrospective analysis of the clinical and laboratory findings from 51 adult horses with chronic diarrhoea revealed that the most common conditions were larval cyathostomiasis (14 cases), idiopathic chronic colitis (nine cases) and alimentary lymphoma (five cases). Five animals had diarrhoea as a result of non-alimentary disease. A diagnosis was reached in 37 cases, but only 15 were made ante mortem. Among the 18 animals (35 per cent) which survived, there were five cases of larval cyathostomiasis, one case of colonic impaction and 12 cases were undiagnosed. The most frequent abnormalities detected in blood samples from the horses were neutrophilia, hypoalbuminaemia, hyperglobulinaemia and high alkaline phosphatase activity. Evidence of carbohydrate malabsorption was found in 16 of 28 cases in which oral glucose tolerance tests were performed. No diagnostic specificity was apparent in either the clinical signs or the laboratory findings.

Autoimmune haemolytic anaemia in eight horses.

Autoimmune haemolytic anaemia was diagnosed in eight horses on the basis of a positive Coomb's test. The disease was considered to be idiopathic in three cases and secondary to another condition in five. The clinical signs included dullness and depression, pyrexia, jaundice and haemoglobinuria. In addition to anaemia, haematological evaluation commonly revealed auto-agglutination of red cells and anisocytosis; reticulocytosis and an increased mean corpuscular volume were less commonly observed. Four horses were successfully treated with dexamethasone, but the other four were destroyed or died because of the underlying disease.

Peritonitis in adult horses: a review of 21 cases.

The clinical signs in 21 adult horses affected by peritonitis (unassociated with gastrointestinal rupture or surgical interference of the abdomen) included colic (18 cases), pyrexia (15 cases), weight loss (six cases) and diarrhoea (five cases). The diagnosis was based on a nucleated cell count in peritoneal fluid greater than 10(10)/litre. Haematological abnormalities (either neutropenia or neutrophilia) were present in 17 animals, and hyperfibrinogenaemia was identified in 14. Twelve of the 21 horses survived after intensive antibiotic therapy; the other nine were destroyed either at exploratory laparotomy or after continued clinical deterioration. Necrosis or perforation of the bowel wall was found post mortem in eight of the horses.

Atrial septal defect and atrial fibrillation in a foal.

Clinical examination of a four-and-a-half-month old foal revealed evidence of progressive heart failure associated with an atrial septal defect and atrial fibrillation. Atrial septal defects are rarely reported in foals and the foal's growth, development and demeanour were normal until a sudden onset of lethargic behaviour. The value of B-mode echocardiography in identifying the congenital lesion is indicated.

Discospondylitis in an adult horse.

Discospondylitis, of presumed bacterial origin, was diagnosed in an adult thoroughbred racehorse. The clinical signs were vague and associated with abnormal mobility of the neck and forelimbs. Clinical pathology showed only a non-specific inflammatory response. A scintigraphic examination revealed the site of the lesion and the diagnosis was confirmed by the identification of radiographic changes affecting two thoracic vertebrae. A prolonged course of antimicrobial agents produced a complete recovery and the horse returned to full athletic use.