Blood samples were obtained from 20 bison (Bison bison) from a ranch in northern lower Michigan, as well as from 20 free-ranging bison of the same sex and similar age from the Badlands National Park in South Dakota. Hematologic and serum biochemical values were determined. The values were comparable in both groups, except for those for BUN, aspartate transaminase, and phosphorus, which were significantly (P < 0.001) higher in the ranched bison than in the free-ranging bison. These differences were attributed to nutritional effects. Impact of age on blood characteristics was assessed in the ranched bison only by comparing values from calves weighing less than 185 kg with those from bison weighing more than 185 kg. Calves had significantly (P < 0.001) higher values for phosphorus and RBC counts and lower total protein values than adults. Adult bison had higher eosinophil and neutrophil counts with lower numbers of lymphocytes, suggestive of a stress leukogram, whereas calves had the typical bovine neutrophil:lymphocyte ratio.

Six mature Holstein bulls were each given 10 mg of phenylbutazone (PBZ)/kg of body weight, PO. Of the 6 bulls, 3 were given 10 mg of PBZ/kg by rapid IV administration 4 weeks later. Plasma concentration-vs-time data were analyzed, using nonlinear regression modeling (sum of exponential functions). The harmonic mean of the biologic half-life of PBZ was 62.6 +/- 12.9 hours after oral administration and 61.6 +/- 7.2 hours after IV administration. The mean residence time was 94.61 +/- 8.44 hours and 90.49 +/- 8.93 hours for oral and IV administration, respectively. The mean total body clearance was 0.0015 +/- 0.0003 L/h/kg, with the mean apparent volume of distribution 0.134 +/- 0.021 L/kg. Mean bioavailability was 73 +/- 2% after oral administration. Phenylbutazone was adequately absorbed from the gastrointestinal tract in bulls. The apparent volume of distribution was small, indicating that PBZ distributed mainly into plasma and extracellular fluid. The total body clearance was also small, which accounted for the long half-life of PBZ in bulls.

The survival of pseudorabies virus in an aerosol was studied under different environmental conditions of temperature and relative humidity. Pseudorabies virus decayed logarithmically with mean half-lives of 17.4 (85% relative humidity, 22 C), 18.8 (25% relative humidity, 22 C), 27.3 (85% relative humidity, 4 C), 36.1 (55% relative humidity, 22 C), and 43.6 (55% relative humidity, 4 C) minutes. Virus survival was significantly improved in environments at 55% relative humidity, compared with those at 85% relative humidity (P = 0.017). Rates of survival were improved in environment at 4 C in comparison with those at 22 C. Results suggest that, under the best conditions of this study, the infectivity of pseudorabies virus in an aerosol decreases by 50% in < 1 hour.

Pharmacokinetic variables and metabolism of IM and IV administered ketamine (15 mg/kg of body weight) were determined in 8 swine (2 adult sows and 6 young pigs). After IM administration, maximal plasma concentration was rapidly reached, but peak concentration varied considerably, although comparison with IV data for the same swine indicated that the drug was almost completely absorbed from the musculature. After IV administration, ketamine kinetics followed a 3-term exponential decrease, indicating rapid initial distribution of the drug to highly vascular tissues including the brain, followed by redistribution into less vascular tissues, and elimination. Redistribution and elimination phases, with similar kinetics as those observed in the IV experiment, also were determined in the IM experiment. After both routes of administration, onset of anesthesia was rapid, and most swine recovered consciousness during the phase of redistribution, indicating that anesthesia is terminated by redistribution of drug from the brain into other tissues, whereas metabolism and excretion are less important for duration of anesthesia induced by ketamine. The time during which the swine resumed a lateral position (sleep time) was positively correlated with plasma ketamine concentration at onset of lateral recumbency, as well as with the area under the plasma concentration-time curve. The minimal plasma ketamine concentration for induction of immobilization was about 2 microgram/ml. In adult sows, ketamine induced profound analgesia, which was not obtained in young pigs; this difference in potency could not be related to pharmacokinetic differences between young and adult swine. With respect to metabolism of ketamine in swine, the major metabolite in plasma was norketamine (metabolite I), whereas a second metabolite (metabolite II) was detected only in low concentrations. Elimination half-life of ketamine was about 2 hours after either IM or IV administration.

The immune receptor-mediated functions of bovine alveolar macrophages (AM) inoculated in vitro with bovine herpesvirus-1 (BHV-1) or parainfluenza-3 (PI-3) virus were tested in the presence or absence of virus-specific antiserum or pulmonary lavage fluids collected from calves 6 days after inoculation with BHV-1 or PI-3 virus. The Fc and C3b phagocytic indices of noninoculated AM, collected from 6- to 16-week-old calves, ranged from 75 to 87 and 59 to 64, respectively, and the binding indices ranged from 5 to 8 and 22 to 28, respectively. Infection of AM with either BHV-1 or PI-3 virus had no significant effect on receptor-mediated phagocytosis or binding, with the exception of a significant (P < 0.05) decrease, from 64 to 46, of the C3b phagocytic index of PI-3 virus-infected AM. The addition of lavage fluids, collected after BHV-1 or PI-3 virus infection, to AM infected with the respective virus caused a significant (P < 0.05) decrease in phagocytic indices with values for the Fc and C3b indices in BHV-1-infected AM decreasing from 81 to 49 and from 47 to 8, respectively, and those for the PI-3 virus-infected AM from 79 to 51 and from 46 to 15, respectively. The binding indices of virus-infected AM increased with the addition of viral lavage fluids, but the only significant (P < 0.05) increase was for C3b binding in PI-3 virus-infected cells, which increased from 33 to 56. Virus-specific serum added to AM infected with the respective virus also caused significant (P < 0.05) decreases in the Fc and C3b phagocytic indices, with those for BHV-1-infected AM decreasing from 81 to 24 and from 47 to 5, respectively, and those for PI-3 virus-infected AM from 79 to 23 and from 46 to 3, respectively. The Fc binding index significantly (P < 0.05) increased with the addition of virus-specific serum from 8 to 34 and from 10 to 42 in BHV-1 and PI-3 virus-infected AM, respectively. The C3b binding index of these AM also increased, but not significantly. Infection of AM with either BHV-1 or PI-3 virus had no significant effect on the phagocytosis of opsonized (OPZ) or nonopsonized (nonOPZ) Staphylococcus epidermidis (SE). The addition of lavage fluids, obtained after BHV-1 infection, to AM infected with BHV-1, significantly (P < 0.05) decreased the percentage of phagocytosis of OPZ-SE from 28 to 21 and had a similar, but less substantial effect, on the phagocytosis of nonOPZ-SE. Lavage fluids collected after PI-3 virus inoculation, added to PI-3 virus-infected AM did not have a notable effect on the phagocytosis of OPZ-SE, but did cause a significant (P < 0.05) decrease in the percentage of phagocytosis of nonOPZ-SE from 25 to 17. The addition of virus-specific serum to infected AM caused significant (P < 0.05) decreases in the percentage of phagocytosis of OPZ-SE and nonOPZ-SE, with the values in the BHV-1-infected AM going from 28 to 11 and 16 to 9, respectively, and in the PI-3-infected AM from 36 to 12 and 25 to 13, respectively. Alveolar macrophages infected with either BHV-1 or PI-3 virus, in the presence or absence of lavage fluids from virus-infected calves or virus-specific serum, killed ingested SE as readily as noninfected AM. On the basis of the findings of this study, we suggest, as with other virus infections, that products of the host antiviral immune response interact with AM infected with BHV-1 or PI-3 virus or cause impaired internalization of receptor-bound particles, resulting in impaired AM antimicrobial functions.

An alcian blue precipitation method for quantifying the hyaluronic acid (HA) and sulphated glycosaminoglycan concentration (SGAG) in solutions containing both compounds was assessed. The assay was found to be rapid and reliable in solutions containing 0 to 200 mg of HA/dl and 50 to 1,000 microgram of SGAG/dl, and was not affected by the presence of protein, hemoglobin, or methemoglobin in concentrations normally found in synovial fluid. The HA and SGAG concentrations in intercarpal synovial fluid from 13 clinically normal and 11 arthritic horses were evaluated. A relationship was not found between the concentration of HA and SGAG and any other synovial fluid variable. The SGAG concentration was found to be markedly high in several of the synovial fluid samples from arthritic horses, but did not correlate with the degree of articular cartilage erosion.