Effects of Escherichia coli heat-stable enterotoxin, atropine, clonidine, and morphine on chloride efflux from isolated enterocytes

The effects of Escherichia coli heat-stable enterotoxin (ST) on chloride efflux rate were investigated in 3 fractions of enterocytes isolated in a villus-to-crypt gradient from porcine jejunum. There was no difference in chloride efflux rates between mature and immature cells from controls. Heat-stable enterotoxin significantly increased chloride efflux in all fractions. Morphine inhibited ST-augmented secretion in mature enterocytes. Atropine or clonidine had no effect. Calcium efflux rates and glucose or glutamic acid metabolism were not altered by ST. The results indicate that ST may stimulate chloride secretion in both villus and crypt cells and that opiates inhibit intestinal secretion by a direct action on villus epithelial cells.     

Bacterial overgrowth associated with a naturally occurring enteropathy in the German shepherd dog

Quantitative and qualitative bacteriological studies were performed on duodenal juice from 19 dogs with chronic small intestinal disease. Bacterial overgrowth was demonstrated in seven German shepherd dogs with minimal histological but specific biochemical abnormalities in the jejunal mucosa. Most frequently this overgrowth comprised bacteria of the normal flora, particularly Escherichia coli and enterococci, but these were occasionally accompanied by bacteria rarely present in the proximal small intestine of the normal dog, particularly Clostridium species. In most cases this overgrowth was associated with raised serum folate and reduced serum vitamin B12 concentrations, a finding consistent with the capacity of many enteric bacteria to synthesise folate and bind vitamin B12.     

A new analgesic drug combination in the horse

A xylazine and butorphanol drug combination produced minimal and transient hemodynamic effects and no significant respiratory depression when administered to 6 healthy horses. Combining xylazine and butorphanol produced a synergistic analgesic effect and provided good chemical restraint for a standing surgical procedure.     

Type C botulism in intensively farmed turkeys

Type C botulism in turkeys has been confirmed on several production sites by demonstrating the presence of toxin in sera from affected birds. Only male turkeys were affected, mortalities being up to 30 per cent. No source of toxin was found. Possible modes of intoxication are discussed.     

Influence of formulation on the efficacy of experimental oil-emulsion Newcastle disease vaccines

Twenty-one experimental oil-emulsion vaccines with different emulsifier contents, aqueous-to-oil ratios, and antigen concentrations were compared by immunization of 4-week-old chickens. Vaccines that contained oil-phase (Arlacel 80) and aqueous-phase (Tween 80) emulsifiers induced 2-to-4-fold higher hemagglutination-inhibition titers than vaccines with only the oil-phase emulsifier. The emulsion vaccines containing both emulsifiers were also more stable at 37 C and less viscous than those containing only the oil-phase emulsifier. Vaccines that had different aqueous-to-oil ratios and contained different quantities of allantoic-fluid antigen (1.2% to 50% of the vaccine volume) induced similar protection against challenge, but hemagglutination-inhibition titers were proportional to the amount of antigen added. Vaccines that had different aqueous-to-oil ratios but contained equal amounts of antigen induced similar hemagglutination-inhibition titers and similar protection against challenge.     

Comparison of oil adjuvant and aluminium phosphate-adsorbed toxoid for the passive immunization of lambs against tetanus

Immunization of ewes with oil emulsion toxoid followed by an aluminium phosphate-adsorbed toxoid both containing 10 Lf per dose, resulted in a very high antitoxin level in their lambs. Two injections of aluminium phosphate-adsorbed toxoid also imparted a passive immunity to lambs which is considered to be adequate to protect them against tetanus for 4 weeks after birth.     

Response of swine to periparturient vitamin C supplementation

Two experiments were conducted, involving 68 third-litter sows and 20 first-litter gilts in Exp. 1 and 82 first-litter gilts in Exp. 2. On d 108 of gestation, the dams were moved into individual crates, stratified by parity and breed, and randomly assigned within strata, to one of two treatments: (1) fed a basal 16% protein corn-soybean meal diet, 1.8 and 2.7 kg once daily before farrowing and for the first 7 d of lactation, respectively, and then ad libitum until pigs were weaned at 28 d of age, and (2) fed the basal diet plus 1 g of L-ascorbic acid (vitamin C)/dam daily from d 108 of gestation through d 7 of lactation and on the same feeding schedule as for treatment 1. In Exp. 1, no effect of vitamin C supplementation was observed in sows or gilts on total pigs born/litter, number of live pigs/litter or average live pig weight at birth, 7 or 28 d of age, or on plasma vitamin C concentration of dams at d 108 of gestation or d 7 of lactation or of pigs at birth, 7 or 28 d of age. However, there was a lower (P less than .01) plasma vitamin C concentration of the dams at d 7 of lactation than at d 108 of gestation. Plasma vitamin C concentration also declined (P less than .01) as pigs aged. In Exp. 2, with all gilts, vitamin C supplementation again showed no effect on any of the reproductive traits measured in Exp. 1. It is concluded that daily supplementation of 1 g of vitamin C to either sows or gilts from d 108 of gestation through d 7 of lactation has no beneficial effect on the reproductive or lactation performance of swine.     

Effect of ethionine on hematologic and serum biochemical values in fasted calves

DL-Ethionine (0.87 g/kg of body weight) was administered IV to 6 fasted (12 hour) Holstein bull calves (4.5 months old). Fasting, which was continued for an additional 48 hours, caused a body weight loss (10.82% to 11.96%), a mild increase in PCV, and an increase in the serum free fatty acids (1.204 mmole/L, fasted; 0.949 mmole/L, fasted ethionine-treated calves). Ethionine caused a decrease in the total plasma proteins from 6.5 g/dl to 5.5 g/dl and total serum lipids from 493.9 mg/dl to 307.8 mg/dl. The decrease in the serum esterified fats included all the lipid fractions (triglycerides, cholesterol, and phospholipids). The calves' WBC and serum enzymes aspartate aminotransferase and L-alanine aminotransferase remained within normal range.