The specificity of serum antibodies for the polypeptides of bovine respiratory syncytial virus (BRSV) was examined, using sera obtained from feedlot and range cattle. Test results in sera from feedlot cattle indicated a 60% rate of seroconversion and 95% seropositivity to BRSV, associated with lack of clinical signs of indicative respiratory tract disease. Exposure to other common respiratory tract viruses also was high (greater than 92% to bovine herpesvirus type 1, bovine viral diarrhea virus, and para-influenza virus type 3). Test results in sera from range cattle indicated BRSV serpositive rates of 28% in calves, 49% in yearling cattle, and 70% in mature cows; clinical signs of respiratory tract disease were not observed in these cattle. Antibodies to BRSV in sera from cattle in both environments reacted predominantly with polypeptides of molecular weight 80,000 through 85,000, 40,000 and 28,000. Reactivity to a glycoprotein of molecular weight between 43,000 and 44,000 and to several glycopolypeptides of smaller molecular weight increased in serum specimens obtained from feedlot cattle between time of entry into the feedlot and slaughter.

Immunoassay of serum ferritin is currently used to evaluate the clinical iron status of human beings, horses, cattle, and swine. Because ferritins are immunologically species specific, a separate assay must be developed for each species. We have developed an ELISA for serum ferritin in dogs, using a monoclonal anti-canine ferritin antibody. Ferritin standards were linear (r = 0.997) from 0 to 80 ng/ml. Recovery of ferritin from canine serum was 94%. Dilutions of pooled canine serum were linear from 0 to 50% (r = 0.994). Within-assay coefficient of variability was 5.5%, whereas assay-to-assay coefficient of variability ranged from 12.5 to 21%. This assay should provide a nonsurgical means of accurately estimating dogs' iron stores.

Ureterocolonic anastomosis was evaluated in 13 clinically normal dogs. Urinary continence was maintained after surgery, and the procedure was completed without technique errors in all but 2 dogs. Three dogs died within 5 weeks (2 of undetermined causes and 1 of aspiration pneumonia and neurologic disease), and 1 dog was euthanatized 4 months after surgery because of neurologic signs. Two healthy dogs were euthanatized 3 months after surgery for light microscopic evaluation of their kidneys. Five dogs were euthanatized 6 months after surgery for light microscopic evaluation of their kidneys. Gastrointestinal and neurologic disturbances developed in 4 dogs at various postoperative intervals. Plasma ammonia concentration measured in 2 dogs with neurologic signs was increased. Plasma ammonia concentration measured in 5 dogs without neurologic signs was within normal limits. All 5 dogs, in which metabolic acidosis was diagnosed, had high normal or above normal serum chloride concentration. Serum urea nitrogen values were increased after surgery because of colonic absorption of urea. Serum creatinine concentration was increased in 1 dog 6 months after surgery. Individual kidney glomerular filtration rate was reduced in 38% (3/8) of the kidneys from 4 other dogs at 6 months after surgery. Of 5 dogs euthanatized at 3 to 4 months after surgery, 4 had bilateral pyelitis, and 1 had unilateral pyelonephritis. Six months after surgery, pyelonephritis was diagnosed in 40% (4/10) of the kidneys from 5 dogs. The ureterocolonic anastomosis procedure is a salvage procedure that should allow complete cystectomy. However, variable degress of metabolic acidosis, hyperammonemia, and neurologic disease may result.

A reproducible model of postweaning colibacillosis was obtained by controlling management and environmental variables to simulate conditions often seen at weaning. Suckling pigs were exposed briefly to starter diet at 1 week of age, weaned at 3 weeks of age, held at an ambient temperature of 20 +/- 2 C, again given the starter diet. One day after weaning, each pig was given 10(10) colony-forming units of enterotoxigenic Escherichia coli strain M1823B (0157:K88ac:H43-LT+ STb+) in broth containing 1.2% sodium bicarbonate via stomach tube. In vitro adhesion by strain M1823B to isolated intestinal branch borders was used to tst pigs for susceptibility to K88. In this model, 3 syndromes were induced in susceptible pigs: (1) peracute fatal diarrhea; (2) moderate diarrhea, weight loss, and fecal shedding of the inoculum strain; and (3) no diarrhea, weight loss, and fecal shedding of the inoculum strain. Rotavirus particles were not found in fecal specimens of pigs with diarrhea. The K88-susceptible, noninoculated control pigs remained clinically normal. It was concluded that susceptibility to adhesion by K88+ enterotoxigenic Escherichia coli was a requirement for the production of disease in this model; inoculation with rotavirus was not necessary.