Cardiopulmonary responses were evaluated in 12 dogs undergoing endoscopy (gastroscopy and enteroscopy). Constant endoscopic insufflation was used to distend the stomach and small intestine for 30 minutes in groups of small (< 10 kg n = 4), medium (10 to 20 kg n = 4), and large (> 20 kg n = 4) dogs. Cardiopulmonary measurements within groups prior to gastric distention (preendoscopy) were compared with postendoscopy measurements and with those made during endoscopy. After distending the stomach and small intestine, increased luminal pressure within the body of the stomach and in the descending duodenum (P < 0.05) and increased abdominal girth (P < 0.05) were observed, with the greatest changes in small dogs. Caudal vena cava pressures and mean arterial and pulmonary artery pressures increased (P < 0.05) during endoscopy. Cardiac index varied, with small dogs having greater cardiac index (P < 0.05) during endoscopy, compared with that in medium and large dogs. Minute volume remained unchanged during insufflation, despite a decrease in tidal volume (P < 0.05), because of an increase in respiratory rate (P < 0.05). Arterial blood gas analysis revealed a mild, mixed metabolic/respiratory acidosis in all groups. Although cardiopulmonary changes associated with gastrointestinal tract endoscopy were common, the changes were often small and of little clinical significance.

Immunoglobulin E is produced in response to parasitic nematodes that undergo blood and tissue migrations. Results of our previous studies indicated that IgE and IgG respond to Dirofilaria immitis in experimentally infected dogs. To determine the association between treatment with the larvicide, diethylcarbamazine (DEC), and antibody responses and to examine the potential influence of infection with a nonfilarid intestinal nematode on isotype-specific immune responses, we monitored, by use of isotype-specific ELISA, separate IgE and IgG responses against D immitis in 4 groups (A-D) of 8 dogs experimentally coinfected with D immitis and Ancylostoma caninum. All dogs were monitored from 2 weeks before inoculation with D immitis, through postinoculation (PI) week 20. Group-B dogs received a daily regimen of 6.6 mg of DEC/kg of body weight. Group-C dogs received 4.95 mg of oxibendazole/kg daily. Group-D dogs received DEC and oxibendazole, equivalent to the daily doses given to dogs of groups B and C. All dogs given oxibendazole had no A caninum at necropsy. Of the groups receiving DEC, 3 group-B dogs each had 1 to 2 D immitis at necropsy. When results of chronologic IgE determination for all groups were statistically compared, only groups B and C had significant (P = 0.0148 and P << 0.00005, respectively) increases in IgE values. Group-C dogs had the highest IgE values from PI week 10 until the end of the study, whereas IgG values were statistically identical to those of group-A dogs. Group-B dogs given only DEC and having the least number of D immitis of all groups, had IgE values that peaked at PI week 6; values were significantly (P = 0.0002) higher than those for all other groups. In Group-B dogs, IgG values increased significantly (P << 0.00005) only at PI week 20 and were significantly (P << 0.00005) decreased after PI week 6, compared with values for all other groups. Group D containing 6 dogs infected with 1 to 18 D immitis found at necropsy had IgE values between those of group-B dogs and those of non-DEC-treated groups at PI week 6. There was no difference in IgG values between 3 groups at PI week 6, and IgE values were found to be a better correlator than were IgG values to the number of D immitis larvae killed in the tissues during this period. All differences in IgG and IgE values not only correlated with treatment status and number of D immitis adults found at necropsy, but also with the developmental stage of D immitis commonly present in the groups at each time point and the number of adult D immitis found at necropsy.

The role of interleukin 1 (IL-1) as an inflammatory mediator during mastitis and the therapeutic effect of recombinant human IL-1 receptor antagonist (IL-1ra) for bovine mastitis was studied. Cows were intramammarily infused with lipopolysaccharide (25 g) in 1 mammary gland. Half the cows also received infusions of 5 mg of IL-1ra into the same mammary gland just prior to endotoxin infusion and 4, 8, and 12 hours later. After endotoxin infusion, tumor necrosis factor and high IL-1 bioactivity were detected in whey from infused glands. Vascular permeability changes and neutrophil accumulation in milk paralleled the appearance of cytokines. A systemic reaction, characterized by pyrexia and an increase in blood cortisol concentration, also were observed. Milk yield was inhibited and milk composition was altered in infused and noninfused glands. The increase in IL-1 bioactivity in milk after endotoxin infusion was almost completely prevented in glands receiving IL-1ra. However, IL-1ra had no effect on local inflammation, systemic reaction, or impairment in productive performance. These results indicate that IL-1 does not mediate its effect within the milk compartment, and suggest either that IL-1 is not critical to the mastitic response or that intramammary infusion of IL-1ra does not place the antagonist where IL-1 interacts with its receptor.

The size and quality of muscle specimens obtained by use of a percutaneous biopsy technique were studied. All biopsies were performed under local anesthesia, using an 11-gauge biopsy needle. The mean +/- SEM size of specimens obtained from 128 biopsies of the semitendinosus muscles of 16 Alaskan Huskies was 23.8 +/- 4.4 mg. All biopsy specimens were of sufficient quality to permit histochemical differentiation of the fiber types by use of myosin ATPase staining. An additional 8 biopsy specimens were obtained from 1 dog and analyzed for muscle glycogen content. These specimens contained 50.6 +/- 7.2 mmol of glucose/kg of muscle wet weight. This modified biopsy procedure was free of notable complications, and repeatable use produced specimens of adequate size and quality for histologic and biochemical analysis. It is concluded that this procedure is a safe and reliable alternative to open biopsy for diagnosis and management of neuromuscular, metabolic, and nutritional myopathies.

Reference values for hematologic variables change with increasing age in cattle. Therefore, the purpose of the study reported here was to describe the peritoneal fluid constitutents of clinically normal young calves, and to compare cellular concentration and distribution in blood and peritoneal fluid of young calves with those of adult cattle. Eight healthy 8-week-old male Holstein calves and 8 healthy 3- to 8-year-old Holstein cows were studied. Peritoneal fluid was collected from calves along the ventral midline, 4-cm cranial to the umbilicus. Abdominocentesis was performed in the region of the lower right flank in adult cattle. Correlation analysis, using the Pearson's correlation coefficient, and regression analysis were performed for blood and peritoneal fluid data from calves. Data from calves were compared with those of cows, using Wilcoxon's rank sum test. A P value < 0.05 was considered significant for all tests. Calves had significantly lower blood eosinophil count (P < 0.003) and plasma protein concentration (P < 0.001) than did cows. Calves had significantly higher peritoneal fluid nucleated cell (P < 0.05) and mononuclear cell (P < 0.05) counts, but lower peritoneal fluid eosinophil cell count (P < 0.003) than did cows. For calves, nulceated cell and lyhocyte cell counts in the blood had a high, positive correlation with those of peritoneal fluid. However, the prediction equation for nucleated cell count accounted for a modest proportion of variability. A prediction equation for peritoneal fluid lymphocyte cell count was established. On the basis of results of this study, reference ranges established for peritoneal fluid constituents of clinically normal adult cattle may not be appropriate for interpretation of peritoneal fluid analysis of calves.

Chickens (n = 18), ranging in age from 30 to 50 weeks and in body weight from 1.1 to 2.1 kg, were anesthetized with isoflurane. Ventilation was controlled, and temperature was maintained at 40.1 +/- 1.0 C. The minimal anesthetic concentration (MAC) of isoflurane was determined by use of a bracketing technique based on purposeful movement in response to a toe clamp. After determining isoflurane MAC in triplicate, birds were given a mu-opioid agonist (morphine, n = 9) or a kappa-opioid agonist (U50488H, n = 9). Determination of MAC was repeated after each IV administration of agonist in progressive doses of 0.1, 1.0, and 3.0 mg/kg of body weight. Heart rate and mean arterial blood pressure (MAP) were recorded immediately before and after each injection. Control MAC (mean +/- SEM) was 1.24 +/- 0.05% and 1.05 +/- 0.03% for the mu- and kappa-opioid agonist groups, respectively. Morphine and U50488H caused a dose-dependent decrease in isoflurane MAC in all birds. Reduction of MAC from control (mean +/- SEW) was 15.1 +/- 2.7, 39.7 +/- 3.1, and 52.4 +/- 4.0% after the 3 successive doses of morphine and was 13.3 +/- 3.0, 27.6 +/- 3.3, and 40.8 +/- 3.8% after U50488H was given. Each opioid injection resulted in significant (P less than or equal to 0.05, repeated measures ANOVA) lowering of MAC. Heart rate and MAP did not change significantly (P less than or equal to 0.05, paired Student's t-test) after any dose of opioid. In conclusion, morphine or U50488H decreased isoflurane MAC in dose-dependent manner without significant effect on heart rate and MAP.

Whereas the clinical efficacy of vaccination against pseudorabies has been studied extensively, methods to evaluate the influence of vaccination on pseudorabies virus (PRV) transmission have only recently become available. In this study, PRV transmission and growth performance in finishing pigs vaccinated either once or twice were compared. The incidence of PRV infections was significantly (P = 0.039) higher in the group vaccinated once (38%) than in the group vaccinated twice (10%). The reproduction ratio R, which is defined as the average number of new infections caused by 1 infectious individual, was estimated in both groups. This ratio was also significantly (P = 0.025) higher among single vaccinated pigs (R = 3.4) than among pigs that had received double vaccination (R = 1.5). In compartments where serologic evidence of PRV introduction was observed, the mean daily weight gain was significantly (P = 0.029) lower in pigs vaccinated once (698 g/d) than in pigs vaccinated twice (721 g/d). Results of this study document the possibility to objectively evaluate the effect of vaccination on PRV transmission under field conditions. From the results, we concluded that double vaccination is advantageous in populations of finishing pigs at risk for PRV introduction. However, even among pigs vaccinated twice, extensive spread of PRV can occur.

The effect that topical administration of cyclosporine would have on the number and type of microorganisms isolated from the corneal surface of dogs with keratoconjunctivitis sicca was studied. Schirmer tear tests were performed on and corneal swab specimens were collected from 61 eyes of 31 dogs with keratoconjunctivitis sicca prior to and after 3, 6, and 12 months of treatment with cyclosporine. In eyes that responded to cyclosporine treatment (Schirmer tear test value increased by greater than or equal to 5 mm/min, compared with pretreatment value), the percentage of eyes from which bacteria were isolated after 3, 6, and 12 months of treatment was significantly (P < 0.001) less than the percentage from which bacteria were isolated prior to treatment. However, among eyes that did not respond to treatment, we did not detect a significant change over time in prevalence of bacteria or type of bacteria isolated. The percentage of eyes from which fungi were isolated decreased during treatment; however, the small number of eyes in which fungal culture results were initially positive precluded demonstration of a significant change. For all eyes, we did not detect any significant differences over time in the frequency with which specific bacterial genera were isolated, with the exception of beta-hemolytic Streptococcus spp. Opportunistic corneal infections were not detected even though none of the dogs received antibiotics. An increase in production of tears, which contain anti-infection proteins, was believed to be the primary factor responsible for the decrease in the percentage of eyes from which microorganisms could be isolated.

The core protein and the transmembrane protein, encoded for the structural genes gag and env, respectively, of caprine arthritis-encephalitis virus were amplified by use of polymerase chain reaction, cloned into a pGEX-2T vector, and expressed in Escherichia coli as fusion proteins with the glutathione S-transferase at their C-terminus. The recombinant proteins were purified and evaluated by use of an ELISA. Sera from 269 goats were tested, and the results were compared with those obtained by use of immunoblot analysis. When results from both recombinant ELISA (r-ELISA) were compared, it appeared that the transmembrane glycoprotein was more immunoreactive than the core protein, because it was recognized by a higher percentage of sera from infected goats. When results of the 2 ELISA (p28 r-ELISA and p40 r-ELISA) were combined in parallel, they were comparable to those of the immunoblot test, with sensitivity of 100% and specificity of 98.3%. It was also found that use of both r-ELISA makes it possible to compare the variable immunoreactivity against gag and env viral antigens, which may be correlated with the disease state. The r-ELISA, using core and transmembrane proteins, appears to be highly sensitive and specific for detection of antibodies against caprine arthritis-encephalitis virus.

Sequential histologic, immunologic, and virologic features of herpesvirus-induced keratitis were studied in 18 experimentally infected cats. Histologic changes were assessed by use of light microscopy, and the presence of viral antigen, B lymphocytes, and T lymphocytes was verified immunohistochemically. Flow cytometry was used to monitor changes in blood T lymphocytes (CD4 and CD8 homologues) and B lymphocytes. Cellular immunity was assessed by use of the lymphocyte proliferation assay. Development of stromal keratitis was preceded by prolonged absence of corneal epithelium, decreased numbers of circulating lymphocyte subsets, decreased mitogen responses, and acquisition of viral antigen by the corneal stroma. Return to normal of circulating lymphocyte numbers and function was temporally associated with the arrival of neutrophils and B and T lymphocytes in the corneal stroma. Sequelae to stromal inflammation were fibrosis and scarring. Findings suggest that suppression of local immune responses allows virus access to the corneal stroma, and that subsequent keratitis is mediated by an immune response to viral antigen.