COMPLICATIONS FOLLOWING A RUPTURED BLADDER IN A 60-DAY-OLD FOAL

The death of a 60-day-old foal due to massive haemorrhage associated with erosion of the left umbilical artery into the left ureter is reported. Surgical repair attempts are described together with post-mortem findings.     

Persistence of Salmonella Typhimurium DT120 in abattoir paddocks holding sheep

In the summer of 1999 there was an outbreak of Salmonella Typhimurium DT120 in people in the north of England which was unusual in being sensitive to antimicrobial drugs. The outbreak was linked to mutton and lamb from a local abattoir, and attention focused on four holding paddocks used to retain sheep before slaughter. In November 1999, samples of soil and faeces were taken from these paddocks and samples of faeces were taken from the concrete race leading from them. Salmonella Typhimurium was isolated from 59 of the 100 samples. Between January 2000 and October 2000 seven visits were made to the abattoir at each of which 100 samples were taken from the paddocks and concrete race and examined for the presence of Salmonella. The paddocks remained heavily contaminated with S Typhimurium DT120 until April when there was a marked reduction in the recovery of the organism. By June the contamination was minimal and by August it had disappeared, and the organism was not recovered in September or October.     

THE EPIDEMIOLOGY OF RINGWORM IN RACEHORSES CAUSED BY TRICHOPHYTON EQUINUM var AUTOTROPHICUM

The epidemiology of dermatomycocis due to Trichophyton equinum var autotrophicum was studied in a number of thoroughbred stables in south-east Queensland. The significant factors in the epidemiology were defined. The infection was readily transmitted, particularly by infected saddle-girths, on which the fungus could survive for 12 months. Mild abrasion from the saddle during work favoured the development of lesions and prolonged the recovery period. A pronounced age and seasonal incidence of the disease was demonstrated as young horses under the age of 3 years were most susceptible, and the majority of cases occurred in periods of high humidity.     

Microvascular permeability changes in ischemia/reperfusion injury in the ascending colon of horses.

The normal microvascular permeability of the ascending colon in horses and the microvascular permeability of that segment after ischemia and reperfusion were investigated. Microvascular permeability was estimated by the ratio of lymphatic protein to plasma protein concentration (Cl/Cp) at high lymph flow rates in 8 adult horses in 2 equal groups: normal and ischemic (2-hour period). Lymphatic flow rates and lymph and plasma protein concentrations were determined. Intestinal biopsy specimens were obtained at the end of each experiment. Flow independent values were selected and compared by one-way ANOVA, and the mean and SEM of these values were determined. The mean Cl/Cp ratios for the flow independent part of each data set were as follows: normal = 0.36 +/- 0.08; ischemic = 0.70 +/- 0.08. These groups were significantly different (P < or = 0.0001). Microscopic evaluation revealed mild congestion and edema in the normal group. The ischemic group had mild to moderate mucosal degeneration, with moderate to severe congestion and edema. We concluded that ischemia of the ascending colon, when followed by reperfusion, results in a significant increase in microvascular permeability.     

A computer-derived protocol to aid in selecting medical versus surgical treatment of horses with abdominal pain

In order to determine which variables are useful in identifying horses with abdominal pain requiring surgery, data were analysed from 219 horses presented at one veterinary teaching hospital. Using multiple stepwise discriminant analysis with a recursive partitioning algorithm, we obtained a decision tree that identifies surgical and non-surgical patients. The prevalence of surgical patients was 79 per cent in this population. The sensitivity, specificity, and positive and negative predictive values of this decision tree were 99 per cent, 55 per cent, 90 per cent and 99 per cent respectively. Compared to the clinical decision, this decision tree yielded more false positives (11 per cent) but almost eliminated false negatives (1 per cent). This decision tree was validated by the jack-knife method and also by evaluation using a new sample in a second veterinary teaching hospital in which the prevalence of surgical patients was 55 per cent. This led to sensitivity, specificity and positive and negative predictive values of 93 per cent, 73 per cent, 81 per cent and 89 per cent respectively.