Epiglottic augmentation was evaluated in 7 horses, using 7 ml of polytetrafluoroethylene (polytef) paste injected submucosally on the ventral surface of the epiglottis. In 6 horses, an Arnold-Bruning intracordal injection syringe, specifically designed to inject polytef into paralyzed vocal folds in human beings, was used. At necropsy 60 days after surgery, group mean thickness measurement 20 mm from the epiglottic tip was 40% greater (P < 0.01) and, at the epiglottic attachment of the aryepiglottic fold, was 29% greater (P < 0.01) in the 6 polytef-augmented horses than in clinically normal nonsurgically treated controls. At necropsy, extensive epiglottic thickening was seen. This thickening was exclusively attributable to distention of submucosal areas in the ventral aspect of the epiglottis, with foreign body granulomata surrounded by fibrous connective tissue. In 1 horse, polytef paste was injected by use of a disposable syringe and needle. Excess ventral epiglottic swelling and exposed epiglottic cartilage was seen during subsequent endoscopy. At necropsy 60 days after surgery, the epiglottic contour remained deformed and a large deep mucosal ulcer was observed at the injection site. Histologic examination revealed necrotizing suppurative inflammation that extended into the epiglottic cartilage. Surgery was not technically difficult to perform through a laryngotomy, and all horses tolerated the procedure without apparent discomfort. Endoscopy performed after surgery revealed unremarkable and uniform response to the polytef paste in 4 horses, and in 3 horses, revealed excess swelling and inflammation of the ventral epiglottic tissue that resolved over time. Overdistention of the submucosal space with polytef may have accounted for the undesirable tissue responses that developed, including excess inflammation in the ventral epiglottic tissue in 3 horses, migration of polytef in 4 horses, and ventral mucosal ulceration in 3 horses. Thickening of the ventral epiglottic surface that was readily apparent in all horses at necropsy could not be reliably distinguished endoscopically in conscious horses. Qualitative changes in epiglottic thickness and contour could be distinguished on lateral-view laryngeal radiographs; however, thickness measurements made from radiographs did not correlate accurately with actual thickness measurements made at necropsy.

Flow cytometric and conventional fluorescence microscopic methods were compared to detect heterologous (rabbit) neutrophil antibody bound to equine neutrophils. Unfixed and paraformaldehyde-fixed neutrophils were treated with normal rabbit serum or various dilutions of an antineutrophil serum. The cells were then reacted with fluorescein conjugates of goat anti-rabbit IgG, staphylococcal protein A, and streptococcal protein G. Antibody binding was evaluated by use of fluorescence microscopy and flow cytometry. Unfixed neutrophils treated with normal rabbit serum did not fluoresce, whereas many of the fixed neutrophils had distinct cytoplasmic and some membranous (nonspecific) fluorescence. Unfixed cells treated with the antiserum had localized areas (capping) of intense membrane fluorescence, whereas fixed cells had bright uniform membranous fluorescence. The intensity of specific fluorescence varied with the antiserum dilution and the conjugate. On flow cytometry, over 80% of unfixed cells treated with antiserum dilutions up to 1:1,024, 1:2,048, and 1:256 fluoresced, respectively, with anti-IgG, protein-G, and protein-A conjugates. Fixed cells generally had similar percentages of fluorescent cells, but at a higher (1-step) antiserum dilution. It was concluded that flow cytometry is more sensitive than conventional fluorescence microscopy to detect antibodies associated with equine neutrophils.

The effect of a high insoluble-fiber (IF) diet containing 15% cellulose in dry matter, high soluble-fiber (SF) diet containing 15% pectin in dry matter, and low-fiber (LF) diet on glycemic control in 6 dogs with alloxan-induced insulin-dependent diabetes mellitus was evaluated. Each diet contained > 50% digestible carbohydrate in dry matter. A crossover study was used with each dog randomly assigned to a predetermined diet sequence. Each dog was fed each diet for 56 days. Caloric intake was adjusted weekly as needed to maintain each dog within 1.5 kg of its body weight measured prior to induction of diabetes mellitus. All dogs were given pork lente insulin and half of their daily caloric intake at 12-hour intervals. Mean (+/- SEM) daily caloric intake was significantly (P < 0.05) less when dogs consumed the IF diet vs the SF and LF diets (66 +/- 3 kcal/kg, 81 +/- 5 kcal/kg, and 79 +/- 4 kcal/kg, respectively). Serum alkaline phosphatase activity was significantly (P < 0.05) higher when dogs consumed the LF diet vs the iF and SF diets (182 +/- 37 IU/L, 131 +/- 24 IU/L, and 143 +/- 24 IU/L, respectively). Mean postprandial plasma glucose concentration measured every 2 hours for 24 hours, beginning at the time of the morning insulin injection, was significantly (P < 0.05) lower at most blood sampling times in dogs fed IF and SF diets, compared with dogs fed the LF diet. As a result, 24-hour mean plasma concentration of glucose (IF, 165 +/- 17 mg/ dl; SF, 169 +/- 19 mg/dl; LF, 218 +/- 29 mg/dl), 24-hour mean plasma-glucose fluctuation (IF, 49 +/- 2 mg/dl; SF, 47 +/- 4 mg/dl; LF, 63 +/- 7 mg/dl), and 24-hour urine-glucose excretion (IF, 31 +/- 10 g/d; SF, 42 +/- 16 g/d; LF, 67 +/- 13 g/d) were significantly (P < 0.05) lower in dogs fed IF and SF diets, compared with dogs fed the LF diet. These variables were not significantly different between dogs fed IF and SF diets. Mean glycosylated hemoglobin concentration also was significantly (P < 0.05) lower when dogs consumed the IF diet, compared with the LF diet (4.3 0.4% vs 5.2 +/- 0.4%, respectively). In dogs with alloxan-induced insulin-dependent diabetes mellitus, consumption of diets containing 15% cellulose or 15% pectin and > 50% digestible carbohydrate on a dry-matter basis resulted in improvement in glycemic control, compared with consumption of a diet containing > 50% digestible complex carbohydrate without added fiber.

Twenty-six clinically normal colostrum-fed dairy calves were allotted to 5 groups. Calves of groups 1 and 2 served as nonvaccinated controls and were challenge-exposed with variable numbers of organisms. Group-3 calves were vaccinated SC with a modified Salmonella typhimurium bacterin. The bacterin was composed of killed acid-hydrolyzed S typhimurium G30/C21 (Re-mutant) whole cells coated with alkali-hydrolyzed S typhimurium LT-2 lipopolysaccharide, as antigen, and monophosphoryl lipid A, as adjuvant. Calves of groups 4 and 5 were vaccinated with a 2% mineral oil-in-water emulsion containing lipopolysaccharide as antigen and monophosphoryl lipid A and trehalose 6-6'-dimycolate as adjuvants. Calves of groups 3-5 were vaccinated at 2 weeks of age and again at 4 or 6 weeks of age. Adverse reactions were not observed after vaccination. Calves were challenge-exposed orally at 6 or 8 weeks of age with 1.5 X 10(11) (groups 1 and 4), or 3.0 X 10(11) (groups 2, 3, and 5) colony-forming units of S typhimurium UCD 108-11. Mortality after challenge exposure was 2 of 5 group-1 calves; 4 of 5 group-2 calves; 5 of 6 group-3 calves; 1 of 5 group-4 calves; and 4 of 5 group-5 calves. Statistical difference between calves of similarly challenge-exposed groups was not evident, indicating failure of either vaccine to protect calves of this age from oral challenge exposure with virulent S typhimurium.

The central arterial pharmacokinetics of alfentanil, a short-acting opioid agonist, were studied in rabbits, sheep, and dogs after short-duration infusion of the drug. Alfentanil was infused until a set end point (high-amplitude, slow-wave activity on the EEG) was reached. This required a larger alfentanil dose and a higher alfentanil arterial concentration in sheep, compared with rabbits and dogs. The plasma concentration-time data for each animal were fitted, using nonlinear regression, and in all animals, were best described by use of a triexponential function. In this study, differences in the disposition kinetics of alfentanil among the 3 species were found for only distribution clearance and initial distribution half-life. In dogs, compared with rabbits and sheep, the first distribution half-life was longer, probably because of pronounced drug-induced bradycardia (mean +/- SD, 48 +/- 21 beats/min). Distribution clearance was faster in sheep, compared with dogs, also probably because of better blood flow in sheep. Elimination half-life was similar in all species (rabbits, 62.4 +/- 11.3 minutes; sheep, 65.1 +/- 27.1 minutes; dogs, 58.3 +/- 10.3 minutes). This rapid half-life resulted from a small steady-state volume of distribution (rabbits, 908.3 +/- 269.0 ml/kg; sheep, 720.0 +/- 306.7 ml/kg; dogs, 597.7 +/- 290.2 ml/kg) and rapid systemic clearance (rabbits, 19.4 +/- 5.3 ml/min/kg; sheep, 13.3 +/- 3.0 ml/min/kg; dogs, 18.7 +/- 7.5 ml/min/kg). On the basis of these pharmacokinetic variables, alfentanil should have short duration of action in rabbits, sheep, and dogs. This may be beneficial in veterinary practice where rapid recovery would be expected after bolus administration for short procedures or after infusion for longer procedures.

Blood, feces, nasal secretions, and tears werecollected weekly from 5 randomly selected 1- to 8-week-old calves in a large commercial dairy herd. Clinical signs and bovine coronavirus (BCV) shedding from the respiratory and enteric tracts of calves were monitored through the 8-week period by direct immunofluorescence of nasal epithelial cells, protein A-gold immunoelectron microscopy on feces, and ELISA on nasal secretions and feces. All samples were analyzed for antibody isotypes to BCV structural proteins by immunoblotting. All calves had BCV respiratory tract infections and 4 of 5 calves shed virus in feces. Several calves had multiple or prolonged periods of BCV respiratory tract or enteric tract shedding or both. All calves (except 1) had passive IgG1 antibodies to some BCV proteins (mainly the E2 and E3 proteins) in their serum when they were 1 week old. The presence of these passive serum antibodies (mainly to the E2 and E3 BCV proteins) was associated with decreased or delayed systemic and mucosal antibody responses in calves, in particular IgA responses in nasal secretions and tears to the E2 and E3 BCV proteins, but not to the N protein. Moderate amounts of maternal BCV E2- and E3-specific antibodies in serum did not prevent BCV enteric tract or respiratory tract infections in calves, but may have delayed the development of active antibody responses to these BCV proteins. However, calves with BCV respiratory tract or enteric tract infections had no detectable passive antibodies to any BCV proteins in nasal secretions or feces.

The effects of the corticosteroid 6-alpha-methylprednisolone acetate on normal equine articular cartilage were evaluated, using the middle carpal joint in 4 clinically normal young horses. One middle carpal joint of each horse was injected 3 times with 100 mg of 6-alpha-methylprednisolone acetate, at 14-day intervals. The opposite middle carpal joint (control) was injected with 2.5 ml of lactated Ringer solution at the same intervals. Effects were studied until 8 weeks after the first injection. Evaluation included clinical and radiographic examination, and gross, microscopic, and biochemical evaluation of joint tissues. Horses remained clinically normal during the study, and significant radiographic changes were not observed. Safranin-0 matrix staining intensity and uronic acid content were significantly (P < 0.05) lower and hydroxyproline content was significantly (P < 0.05) higher in articular cartilage of corticosteroid-injected joints vs control joints.

Dogs were treated with flunixin meglumine, a cyclo-oxygenase inhibitor; L-651,896, a 5-lipoxygenase inhibitor; and matrine, a herbal anti-inflammatory drug. Acute inflammation was induced in the eyes by disruption of the anterior lens capsule, using a neodymium:yttrium aluminum garnet laser. Intraocular pressure, pupil diameter, and eicosanoid production in the aqueous humor were measured. Statistically significant effects were seen in the eyes of flunixin meglumine-treated dogs where mydriasis was maintained and aqueous prostaglandin E2 concentration was reduced.

Recordings of averaged brain stem auditory-evoked potentials were obtained from 13 Beagle pups of both genders to document the postnatal development of the response from age 1 to 76 days. Responses were recorded between needle electrodes placed on the vertex and the ipsilateral ear, with ground at the interorbital line. Recordings were performed without sedation. Low-amplitude responses to high-intensity stimuli could be recorded from animals prior to opening of the ear canals. Peak latencies did not change after day 20 for peak I, day 30 for peaks II and III, and day 40 for peak V. As a result, the interpeak latencies between peaks I and III did not change after day 30, but continued to decrease until day 40 for peaks III-V and I-V. Peak amplitudes reached plateau values by day 20 (peak I) or day 30 (peaks II, III, and V). All of the measured latency and amplitude values had significant (P <0.001) linear regression lines of latency vs age and amplitude vs age. The brain stem auditory-evoked potential thresholds were mature by day 20.

Twelve ponies were used to evaluate the reliability of an abdominal adhesion model and the efficacy of intraperitoneal infusion of sodium carboxymethylcellulose in preventing abdominal adhesions. A celiotomy was performed on each of the 12 ponies and the serosa of the distal portion of the jejunum was abraded with a dry gauze sponge at 5 locations. In addition to the serosal damage, a single 2-0 chromic gut suture was placed through the seromuscular layer of the jejunum in the center of the abraded area. After closure of the celiotomy, a 1% solution of sodium carboxymethylcellulose (7 ml/kg of body weight) was infused into the peritoneal cavity of 6 ponies. The other ponies served as untreated controls. All ponies were euthanatized 14 days after surgery. All ponies in the control group had abdominal adhesions at the time of necropsy. Four of the 6 ponies in the treatment group were free of adhesions. There was a significant (P < 0.0001) difference in the total number of adhesions between the 2 groups.