The purpose of this study was to determine the safety and efficacy of a live Salmonella choleraesuis immunizing strain, obtained by repeated ingestion and recovery through porcine neutrophils. The strain was tested in mice and in pigs. The vaccine was safe and effective in controlled experimental trials, using clinical, pathologic, and microbiologic criteria. Vaccinated pigs were able to maintain normal weight gains during the 4-week observation period following challenge inoculation with a high dose of a virulent strain.

Assays were developed to detect and measure antibodies (AA) to thyroglobulin (Tg) and to the thyroid hormones, thyroxine (T4) and triiodothyronine (T3). An ELISA to detect AA to Tg was developed, using purified canine Tg as the antigen and goat anti-canine IgG conjugated with alkaline phosphatase as the second antibody. A highly charged agarose electrophoresis assay was used for determination of AA to T4 and T3. Sera from dogs (n = 119) with clinical signs consistent with hypothyroidism were tested for AA to Tg, T4, and T3. Autoantibodies to at least 1 of the 3 thyroid antigens were detected in 58 of the 119 (48.7%) sera tested. Autoantibodies to Tg were detected more frequently in samples with low serum concentrations of thyroid hormones than in samples with normal concentrations. The presence of AA to T4, T3, or both was not significantly associated with low thyroid hormone concentrations, but this lack of association may have been attributable to binding of AA in the measurement of thyroid hormones by radioimmunoassay.

Purebred Beagles were inoculated with Trypanosoma cruzi isolates from a North American opossum or armadillo (Tc-W), and dog (Tc-D). Although Tc-D established infection in dogs, the dogs did not develop cardiac abnormalities. Dogs inoculated with Tc-W developed acute myocarditis associated with increases in P-R interval, atrioventricular block, depression of R wave amplitude and shifts in mean electrical axis. Echocardiograms were normal during this stage. Three Tc-W-inoculated dogs died during the acute stage. Following the acute stage, 5 of 8 Tc-W-inoculated dogs entered an indeterminate stage in which ECG changes were minor and echocardiograms were normal. Progression to the chronic stage in 5 of the 8 Tc-W-inoculated dogs was indicated by development of ventricular-based arrhythmias, mainly ventricular premature contractions, between postinoculation days 60 and 170. In some dogs, ventricular premature contractions were multifocal. Electrocardiographic abnormalities progressively degenerated to various forms of ventricular tachycardia. Worsening ECG coincided with loss of left ventricular function as measured by echocardiography. Mean percent ejection fraction and percentage of fractional shortening decreased to 63% and 52% of control values, respectively. The left ventricular free wall (LVFW) thickness decreased and % septal: % LVFW thickening ratio increased, indicating a relative preservation of septal wall motion and LVFW hypokinesis.

We examined the efficacy of ivermectin in the control of ear mites (Psoroptes cuniculi) in rabbits. The study involved 40 female and 35 male rabbits that were known to be naturally infested with ear mites. After a period of acclimation to the animal care facilities, the rabbits were ranked on the visual appearance of any ear lesion and the number of mites on glycerin-dipped ear swabs. The rabbits were then randomly assigned to 1 of 4 treatment groups; vehicle only (group 1), 50 micrograms of ivermectin/kg of body weight (group 2), 100 micrograms of ivermectin/kg (group 3) and 200 micrograms of ivermectin/kg (group 4). The rabbits were treated by SC injections on day 0 and day 14 of the trial; thus, the total dose of ivermectin given to groups 1 through 4, was 0, 100, 200, or 400 micrograms/kg, respectively. The study ended 2 weeks after the last treatment. Ear lesions of the treated rabbits improved significantly (P < 0.001). By 28 days after the first treatment, the mean number of mites on the ear swabs (both ears) was 57.5 for untreated rabbits and 9.1, 0.5, and 2.5, respectively, for rabbits in groups 2, 3, and 4. The mean number of mites recovered from the ears of the untreated rabbits at necropsy was 24,297. For groups 2, 3, and 4, the mean number of mites recovered from the ears was 5,352, 96, and 96, respectively. The efficacy of treatment with a total dose of 100 micrograms/kg was 77.96%, with 200 micrograms/kg was 99.61%, and for 400 micrograms/kg was 99.61%.

The ability of polysulfated glycosaminoglycans (PSGAG) to inhibit the complement cascade was evaluated. The role of complement in inflammation and infection has been well documented. Inhibition of the complement cascade by PSGAG could explain why intra-articularly administered PSGAG diminish diarthrodial joint inflammation and potentiate septic arthritis in horses. Hemolytic complement testing was performed to evaluate the effect of PSGAG on the equine classical and alternate pathways of complement, using rabbit erythrocytes as the target cells. Concentration of PSGAG between 0.2 mg/ml and 0.6 mg/ml significantly (P < 0.05) inhibited equine complement in dose-related fashion. Further increase in complement inhibition was not observed at PSGAG concentration > 0.6 mg/ml. Difference was not apparent in the extent of inhibition of complement from each of the 4 horses tested. Polysulfated glycosaminoglycans appeared to inhibit the classical and alternate complement pathways equally, indicating possible effect on complement components common to both pathways. Heat inactivation of complement function completely inhibited (P < 0.01) the hemolytic activity of the serum from all horses.

Concentrations of serum and vitreous humor constituents at time of death, and concentrations of vitreous humor constituents at time of death and at 7 postmortem intervals were compared in 70 domestic, female New Zealand White rabbits (Oryctolagus cuniculus). Urea nitrogen concentration was significantly (P = 0.0094) different, but was linearly correlated in serum and vitreous humor at time of death and at the 4- and 8-hour postmortem intervals. Concentrations of gamma-glutamyltransferase were not significantly different in serum and vitreous humor at time of death, nor were concentrations significantly different in vitreous humor at time of death and at the 4-hour postmortem interval. The vitreous humor concentrations of glucose, triglycerides, sodium, potassium, cholesterol, total protein, albumin, lactate dehydrogenase, creatine kinase, aspartate transaminase, bilirubin, cortisol, and IgG were neither similar to nor predictive of serum constituents. Vitreous humor can be used as a source for estimates of serum urea nitrogen and gamma-glutamyltransferase up to 8 and 4 hours after death, respectively.

The aerobic bacterial flora of the genital tract was characterized in 59 bitches in an 18-month study. The bitches represented 4 breeds and were from 3 kennels. Collection of vaginal swab specimens for bacterial culturing was performed every month, except during estrus when specimens were collected every week (n = 826). The capsule of the swab containing transport media was broken before specimen collection to moisten the tip, which helped to reduce the number of negative cultures. All bitches whelped at least once during the study and, thus, had known reproductive functions. Pregnancy rates, litter sizes, and pup mortality were within normal limits. Pasteurella multocida, beta-hemolytic streptococci group G, and Escherichia coli were the most common bacteria isolated. Although these species generally were isolated from mixed cultures, pure cultures were obtained from 18% of the specimens. There was a tendency for the various breeds to differ in their vaginal bacterial flora. The flora also varied during the reproductive cycle. Pasteurella multocida was isolated significantly more often during proestrus, estrus, metestrus, and pregnancy, than during anestrus and the postpartum period, and beta-hemolytic streptococci were isolated significantly more often during proestrus than during estrus, pregnancy, or the postpartum period. Staphylococcus intermedius was almost exclusively found after parturition. Culture results were negative for only 5.2% of specimens cultured. On the basis of our findings, bacterial culturing of vaginal swab specimens from bitches without signs of genital disease is of little value.

Neutrophil migration through bovine teat tissues into the teat cistern, after endotoxin infusion into the teat cistern, was determined in vivo by 2 experimental procedures, indium-111 labeling of blood neutrophils, and obtaining multiple biopsy specimens from the teat cistern tissues. In both experiments, the number of leukocytes in the teat cistern flushing samples was continuously measured. A lag phase of approximately 1 hour was required between endotoxin infusion into the teat cistern and the first observed neutrophil accumulation in the teat tissues. The rate of neutrophil accumulation in the teat tissues was highest between postinfusion (pI) hours 1 and 2, and the accumulation process ceased after PI hour 3. Neutrophils migrated toward the epithelium, and intraepithelial neutrophils were observed beginning approximately 2 hours after infusion, which coincided with the first influx of cells into the teat cistern. The cell influx into the teat cistern increased continuously up to PI hour 3, peaked between PI hours 3 and 5, and was close to preinfusion value at PI hour 22. Use of indium-111-labeled neutrophils in the study of the inflammatory process provides a reliable noninvasive method to quantify cell migration in vivo. Use of biopsies allows quantification of the number of cells in different tissue areas, but has the disadvantage of being invasive. These 2 procedures complement each other, and could be of use in future studies of the local inflammatory process.

Collection of exocrine pancreatic secretions from cattle by use of a single-unit cannula was performed. The major advantage of the cannula was simple technical management. A small pouch of the duodenum into which the major pancreatic duct drains was formed. Continuity of the duodenum was reestablished by end-to-end anastomosis. A side arm of the cannula was inserted into the pouch to collect exocrine secretions, and the main portion of the cannula was placed cranial to the anastomosis to return pancreatic secretions to the small intestine between collection periods. The accessory pancreatic duct was ligated in 2 of 4 cattle to evaluate possible secretory contribution from this source. All cattle remained healthy after cannulation, and cattle gained approximately 100 kg of body weight in the 5 months after surgery. The mean secretory rate for exocrine pancreatic secretion in cattle was 106 +/- 6.8 ml/h. There was no effect of feeding on the pattern of secretion nor were there significant differences between cattle. A fistula formed between the pouch and duodenum approximately 120 days after surgery in the first 2 cattle used. Development of fistulas was prevented for 300 days in subsequently prepared cattle by use of surgical mesh around the cannulas, leading to functional cannulation sites. Preparation of a duodenal pouch appeared useful for long-term studies of pancreatic exocrine secretion in cattle.

Eighteen ponies were inoculated IV with Ehrlichia risticii-infected P388D1 mouse monocyte cells. Twenty-four hours after onset of fever (rectal temperature > 38.8 C), 9 ponies were treated with oxytetracycline (6.6 mg/kg of body weight, IV, q 24 h) for 5 days. The remaining 9 ponies served as infected nontreated controls. Mean scores of the following variables were not significantly different between groups on the day treatment was begun: rectal temperature, diarrhea, borborygmal sounds, feed intake, mental attitude, and evidence of a hyperresonant area in the abdomen. All ponies were observed for progression of clinical signs typical of ehrlichial colitis. Within 12 hours of initiation of treatment, only 1 treated pony had a rectal temperature > 38.8 C and most rectal temperatures were < 38.3 C. In contrast, only 2 control ponies had rectal temperatures < 38.8 C (mean rectal temperature values were significantly, P = 0.01, different between groups). In the treatment group, 4 ponies had no signs of depression after the first day of treatment, and only 1 had signs of depression after the second day of treatment (mean scores between groups were significantly different, P = 0.01). Feed intake remained normal in 4 treated ponies and improved in 4 of the remaining 5 after treatment began. Most of the control ponies had a progressive decrease in their feed intake during the observation period (mean scores between groups were significantly, P = 0.01, different). Three ponies in the control group and 2 ponies in the treatment group developed diarrhea before the treatment observation period began. Of the remaining 6 control ponies, 4 developed diarrhea after the treatment observation period began. None of the ponies in the treatment group developed diarrhea after treatment began. A profound decrease in borborygmal sounds, with silent periods lasting longer than 3 minutes, developed in 7 control ponies. Only 2 treatment ponies had borborygmi decreased to this level (mean scores between groups were significantly, P = 0.01, different). Three of 9 control group ponies developed severe disease and were euthanatized. All treatment-group ponies survived. In surviving ponies, clinical signs lasted 8 to 16 days (mean, 11.5) in the control group, but lasted only 1 to 7 days (mean, 4.5) in the treatment group (P = 0.01). Ponies from the treatment group did not develop clinical signs when reinoculated with Ehrlichia risticii at 4 and 8 months after original inoculation.