Detailed Pathophysiologic Studies of Intestinal Obstructions in Goats

Abstract

Literature is available on studies of physical signs and blood biochemistry in horses with intestinal obstruction (Datt and Usenik, 1975). In cattle, Hammond e_t aj_. (1964), studied the effects of obstruction on water and electrolyte metabolism. Studies on effects of strangulated intestinal obstruction on peritoneal fluid and blood parameters in buffalo calves was conducted by Krishnamurthy et al. (1980). In sheep, Gingerich and Murdick (1975), studied paradoxical aciduria during intestinal obstruction. However, these studies are not exhaustively comprehensive about different ruminant species. No literature was available to us on studies in goats. The present investigation is designed to study the pathogenesis of intestinal obstruction at different sites in the goat. Eighteen Masai goats were used in these experiments. They were divided into 3 groups. Group A consisted of C female goats which were subjected to simple duodenal obstruction. Group B consisted of 6 female goats which underwent strangulating obstruction of jejunum. Finally, group C consisted of 6 male goats which were subjected to strangulating obstruction involving the ileoeaecocolic junction. * Obstruction was achieved in each case by ligation of the intestine and the mesentery with a double-loop of plastic tubing. Parameters taken from each goat over the 48 hour-period immediately preceding the obstructions, served as control for each of these goats.Three other goats which were not subjected to any obstruction, were used for histopathologic control. Clinical features were monitored every 6 hours. Blood parameters including: sodium, potassium, chloride, blood urea nitrogen, packed cell volume, erythrocyte count, haemoglobin concentration, leucocyte count, plasma protein and serum albumin, were all monitored every 12 hours. Also monitored every 12 hours were the urinary parameters including: colour, transparency, quantity, specific gravity, urinary pH, protein, glucose, ketones, and the rate of excretion of sodium, potassium and chloride. Peritoneal fluid was sampled every 12 hours, and analysed for colour, transparency, odour, erythrocyte and leucocyte count. After death, necropsy was performed with more emphasis on the gastrointestinal tract. Histopathologic studies on intestinal tract were carried (xvi) out. (xvii) Dehydration' was a main clinical feature in the 3 groups, but reached a higher degree in group A. Gastrointestinal stasis was evident termina11y in all the groups. All the goats in these groups had splashing abdominal fluid sounds, but those in group A had symmetrical abdominal distension in addition. The survival order in increasing survival time, was B. C & A respectively. There was hypernatraemia in group A, hypokalaemia in group B, while hypochloraemia, and elevated blood urea nitrogen were observed in the 3 groups. Oliguria, elevated urinary specific gravity, lowered urinary pH, and decreased rate of urinary excretion of sodium and chloride were observed in the 3 groups. Increased peritoneal fluid, as well as elevated leucocyte count in this fluid was an invariable finding in all the groups. Congestion and haemorrhages were grossly evident on intestinal serosal surface, and it was more severe in the strangulated loops. Mucosal haemorrhages were grossly seen in the strangulated segments. The lumen of the strangulated loops was filled with dark- red fluid contents. Histologically, there was loss of villus epithelium in group A, and loss of villus architecture in groups B & C. • Congestion, haemorrhage and oedema in the lamina propria, submucosa, and sometimes in the tunica muscularis and serosa were evident in the 3 groups. These lesions were more marked in groups B & C. Cellular infiltration into the intestinal wall layers, especially the tunica mucosa, included neutrophils and macrophages.