Gastric emptying of liquids in the dog: effect of volume

Effect of liquid test meal volume on gastric emptying was investigated in healthy nonoperated dogs fed meal sizes of 6.6 to 110 ml/kg of body weight. For meals less than or equal to 66 ml/kg, the amount of test meal emptied from the stomach in 30 minutes vs meal size could be described as following a linear, exponential, or square root pattern. Deviation from these patterns was seen with test meals of 77, 88, and 110 ml/kg. A mean +/- SEM maximum of 0.99 +/- 0.06 ml/kg/min of liquid test meal was emptied from the stomach of dogs fed test meals of 77, 88, and 110 ml/kg. Massive gastric distension induced in dogs during this study did not alter gastric emptying of the liquid test meal.     

Effect of a change in environmental temperature on heat tolerance in laying fowl

Laying hens when transferred from accommodation at an ambient temperature (Ta) of 30 degrees C to one of 20 degrees C failed to acclimatise to intermittent heat stress (Ta 38 degrees C) commencing one day after the transfer. After 21 d of intermittent exposure to 38 degrees C these hens showed little or no increase in heat tolerance, whereas hens living constantly at either Ta 20 degrees C or 30 degrees C acclimatised normally. The failure to acclimatise was also observed when hens were transferred from Ta 30 degrees C to 5 degrees C but not when transferred from Ta 5 degrees C to 30 degrees C. The failure to acclimatise following transfer from a warm to a cool environment was accompanied by an increase in food intake; if food intake was not allowed to increase the hens acclimatised normally to heat stress.     

Evaluation of leukapheresis and thrombocytapheresis in the horse

Continuous-flow centrifugation leukapheresis techniques were used to collect 300-ml volumes of leukocyte-rich plasma from 5 nonmedicated horses and from 5 corticosteroid-stimulated horses. White blood cell counts and differential counts were performed on the horses before (base line) and up to 48 hours after leukapheresis. Systemic administration of hydrocortisone increased numbers of total WBC and neutrophils and improved harvest of these cells. Nonmedicated horses had a mean yield of 3.38 X 10(10) leukocytes in the 300-ml volume. Stimulated horses yielded a mean of 6.88 X 10(10) leukocytes. After leukapheresis, WBC counts decreased a mean of 38% in nonstimulated horses and decreased a mean of 30% in stimulated horses. By 6 hours after leukapheresis, circulating WBC counts of horses in both groups had returned to preleukapheresis values. The relationship between neutrophil yield and the 4 variables (preleukapheresis WBC count, preleukapheresis neutrophil count, preleukapheresis lymphocyte count, and the PCV of the leukocyte-rich plasma) were examined, using simple (pair-wise) correlation and multiple linear regression. A significant positive correlation was found between neutrophil yield and preleukapheresis WBC and neutrophil counts. Because sodium citrate was used in the collection system to prevent extracorporeal blood coagulation, ionized and total serum calcium concentrations were monitored before and after leukapheresis. Although total serum calcium concentrations remained unchanged, ionized calcium concentrations decreased approximately 33% from base-line values during the 2-hour leukapheresis procedures. Occasional mild muscle fasciculations were the only adverse clinical signs of citrate toxicity exhibited by the horses.(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolation of Leptospira interrogans serovar bratislava from sows in Iowa

Leptospira interrogans serovar bratislava was recovered from 2 of 10 sows examined from an Iowa slaughterhouse. Isolations were made from the kidney and genital tract of each sow. Serovar bratislava is not included in vaccines because it has not been previously isolated in the United States.     

Pharmacokinetics of metronidazole given to horses by intravenous and oral routes

Serum and peritoneal fluid concentrations of metronidazole were determined in 6 healthy adult horses given the drug (25 mg/kg) by IV or oral routes. The disposition of metronidazole in horses given the drug by the IV route conformed to a 2-compartment model with a distribution half-life of 0.16 hours, an elimination half-life of 2.9 hours, and a body clearance of 0.40 +/- 0.05 L/kg/hr. The oral absorption half-life was 0.40 hours, and the bioavailability, 85.0 +/- 18.6%. Peritoneal fluid concentrations were approximately equal to serum concentrations at all times, regardless of the route of administration. On the basis of reported minimal inhibitory concentrations for anaerobic bacteria, a dosage of 15 to 25 mg/kg given orally 4 times daily was recommended.     

Counter current line absorption immunoelectrophoresis in an alternative diagnostic screening test to counter current immunoelectrophoresis in Aleutian disease (AD) eradication programs

Counter current immunoelectrophoresis (CCIE) is the diagnostic method used in the ongoing Aleutian disease virus eradication program on Danish mink farms. There has been an increasing demand for an alternative diagnostic test especially to evaluate suspected false positive CCIE reactions. We compared test results of a number of negative and positive mink sera in indirect counter current immunoelectrophoresis (ICCIE), counter current line absorption immunoelectrophoresis (CCLAIE) and radio immuno assay (RIA) with test results from counter current immunoelectrophoresis and found that counter current line absorption immunoelectrophoresis is the best alternative diagnostic screening test to counter current immunoelectrophoresis for Aleutian disease eradication programs. Not only proved the CCLAIE test to be useful for evaluation of doubtfully positive CCIE reactions, but it was found to have a higher sensitivity than the CCIE test.     

Examination of rams culled during an ovine brucellosis accredited free flock scheme

During the early stages of an Ovine Brucellosis Accredited Free Flock Scheme in New South Wales 62 rams were examined to determine the status of their flocks of origin with regard to infection with Brucella ovis. Forty rams were selected because they were either single reactors to low titre or one of a small number of reactors in a B. ovis complement fixation test of the whole ram flock. Twenty two rams were selected because they had palpable abnormalities within the scrotum but were negative serologically. After serological, pathological, bacteriological and histological examinations they were classified in the ensuing categories: 7 positive, 7 inconclusive, 26 false positive and 22 with other lesions. The usefulness of this classification, particularly within the accreditation scheme is discussed.     

Ovum formation and multiple ovulation in lines of white Plymouth Rocks and their crosses

The production of double-yolked eggs and the duration of the rapid growth phase of yolks were measured in parental lines of White Plymouth Rock pullets and their crosses over 30 d, commencing with the day of first egg. Significant differences were found between mating combinations in the incidence of multiple-yolked eggs, but not in the period of rapid yolk growth. Heterosis and recombination effects for multiple ovulation were respectively -9% and -66% of the mean, while the corresponding values for the period required for rapid yolk growth were -1% and -5%. Three double-yolked eggs were observed containing yolks which differed by 3 d in their periods of rapid growth. Hypotheses are were presented for the origin of double-yolked eggs.     

Relationship between mastitis pathogen numbers in bulk tank milk and bovine udder infections in California dairy herds

Samples of bulk tank milk and cow-composite milk from 23,138 dairy cows from 50 California dairies were examined by use of microbiologic procedures. The number of colonies of mastitis pathogens isolated per milliliter of bulk tank milk (used as a predictor of the percentage of infected cows in the herd) was evaluated, using simple regression analysis and Spearman's rank correlation. Correlations between the pathogens and the percentage of cows in each herd shedding the pathogens were found for Streptococcus agalactiae (r = 0.71) and mycoplasma (r = 0.59), but were considerably lower for other pathogens. When greater than or equal to 4,000 colonies of Streptococcus agalactiae were found per milliliter of bulk tank milk, at least 7% of the cows in the herd was shedding this organism. However, a pattern was not found between the number of mycoplasma colonies per milliliter of bulk tank milk and the percentage of infected cows in the herd.