Surgical repair of a comminuted distal femoral fracture in a dog.

This case illustrates that good results may be achieved with fractured femur that was severely comminuted (i.e. a "Humpty Dumpty" fracture). The blood supply at the fracture site must be carefully preserved. The bony architecture must be reestablished with perfect reduction of the articular surfaces, preferably with interfragmentary compression between the bone fragments. These fragments are held in place with screws and Kirschner wires. Some of the screws and pins were left in place as the trauma incurred to retrieve them would have done more harm than good due to bony overgrowth.

Vascular ring anomalies: case report and brief review.

During early fetal life six pair of aortic arches surround the esophagus and trachea. Normal maturation and selective regression of these structures form the adult vasculature. Abnormal location or development of the aortic arches may result in pressure on adjacent organs. Vascular ring anomalies must be considered with any patient with a history of regurgitating food shortly after eating. Physical examination, test feedings, survey and contrast radiographs may give an accurate impression of the problem but a final diagnosis can only be made following surgical exploration. In the case presented, the dog had all the clinical and diagnostic signs suggestive of a vascular ring anomaly. Thoracotomy and elimination of the vascular constriction around the esophagus was both diagnostic and therapeutic for the condition. It is important that owners be made aware that surgical correction of the stenosis does not guarantee a successful conclusion to the case. If the dilation of the esophagus cranial to the stenosis is severe, accumulation of food with subsequent regurgitation may persist. A dilation of the esophagus caudal to the stenosis is present in a large percentage of cases and this also may result in an unrelenting problem. Unfortunately, the probability of these complications cannot be accurately evaluated prior to treatment.The hereditary potential for this defect must also be considered. Congenital vascular anomalies such as patent ductus arteriosus would seem to have a hereditary basis. Therefore, it is probably correct to advise against breeding affected animals. Further, the inbreeding of nonaffected animals which come from litters containing affected animals should be avoided.

Permeability properties of swine small intestine: effect of a heat stable Escherichia coli enterotoxin.

The permeability of weanling swine small intestine was estimated using measurements of filtration coefficients and equivalent pore size. Hypertonic solutions of mannitol, erythritol and urea were used to calculate reflection coefficients in the duodenum, mid jejunum and distal jejunum. Estimated effective pore radius was 6.4-7.4, 5.6-7.2 and 4.7-4.9A degrees in the three respective regions. Similarly the filtration coefficient induced by hypertonic solutions of mannitol decreased significantly in the distal jejunal segments. The results show an aboral gradient of decreasing permeability along the small intestine of the weanling pig. In situ incubation of loops in the proximal jejunum with a heat stable Escherichia coli enterotoxin for one hour did not significantly change the effective pore size as calculated from reflection coefficients of hypertonic solutions of erythritol and urea. However, the filtration coefficients of loops exposed to the enterotoxin were significantly greater than control loops with hypertonic solutions of erythritol and urea but not mannitol. This suggests the occurrence of a slight reduction in epithelial porosity. The results support the hypothesis that intestinal secretion induced by heat stable E. coli enterotoxin is not the result of an increased mucosal permeability.