OBJECTIVE To examine whether expression of extracellular matrix metalloproteinase inducer (EMMPRIN) can be detected in equine lungs and whether it correlates with matrix metalloproteinase (MMP)-2 and -9 expression in bronchoalveolar lavage fluid (BALF) of horses with chronic inflammation of the lungs (ie, lower airway inflammation [LAI]). ANIMALS 29 horses with signs of chronic respiratory tract disease, which were classified as the LAI (n = 17) and LAI with respiratory distress (RDLAI [12]) groups, and 15 control horses. PROCEDURES BALF, tracheal aspirate, and blood samples were obtained, and EMMPRIN expression was determined from BALF cells and RBCs by use of western blotting. Activities of MMP-2 and -9 were determined with zymography. RESULTS Expression of EMMPRIN protein was identified in BALF cells of all horses. Expression of EMMPRIN protein was highest for the RDLAI group and was correlated with MMP-2 and -9 protein expression, MMP-9 gelatinolytic activity, and airway neutrophilia. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that EMMPRIN was involved in the pathophysiologic processes of asthma in horses. However, additional studies of horses and other species are warranted to elucidate the regulation of EMMPRIN expression in asthmatic lungs.

OBJECTIVE To assess the effect of decreased platelet and WBC counts on platelet aggregation as measured by a multiple-electrode impedance aggregometer in dogs. ANIMALS 24 healthy dogs. PROCEDURES From each dog, 9 mL of blood was collected into a 10-mL syringe that contained 1 mL of 4% sodium citrate solution to yield a 10-mL sample with a 1:9 citrate-to-blood ratio. Each sample was then divided into unmanipulated and manipulated aliquots with progressively depleted buffy-coat fractions such that 2 to 3 blood samples were evaluated per dog. The Hct for manipulated aliquots was adjusted with autologous plasma so that it was within 2% of the Hct for the unmanipulated aliquot for each dog. All samples were analyzed in duplicate with a multiple-electrode impedance aggregometer following the addition of ADP as a platelet agonist. The respective effects of platelet count, plateletcrit, Hct, and WBC count on platelet aggregation area under the curve (AUC), aggregation, and velocity were analyzed with linear mixed models. RESULTS WBC count was positively associated with platelet AUC, aggregation, and velocity; blood samples with leukopenia had a lower AUC, aggregation, and velocity than samples with WBC counts within the reference range. Platelet count, plateletcrit, and Hct did not have an independent effect on AUC, aggregation, or velocity. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that WBC count was positively associated with platelet aggregation when ADP was used to activate canine blood samples for impedance aggregometry. That finding may be clinically relevant and needs to be confirmed by in vivo studies.

OBJECTIVE To determine corneal thickness of eyes of healthy goats, sheep, and alpacas by use of a portable spectral-domain optical coherence tomography (SD-OCT) device and evaluate intraoperator reliability for measurements. ANIMALS 11 female goats, 10 female sheep, and 11 (4 males and 7 females) alpacas. PROCEDURES Each animal was sedated, and gentle manual restraint was used to ensure proper positioning of the head and globe. Corneal pachymetry was performed (in triplicate) with a portable SD-OCT device on both eyes of each animal. All corneal measurements were obtained manually by use of the integrated caliper function. Corneal epithelial thickness (CET), corneal stromal thickness (CST), Descemet membrane thickness (DMT), and total corneal thickness (TCT) were measured twice on each image, and a mean value was calculated. RESULTS Mean ± SD values for CET, CST, DMT, and TCT were 96.1 ± 5.0 μm, 486.0 ± 10.3 μm, 36.8 ± 4.8 μm, and 616.9 ± 7.1 μm, respectively, for the goats; 111.6 ± 5.7 μm, 599.8 ± 10.0 μm, 31.0 ± 4.5 μm, and 741.1 ± 9.9 μm, respectively, for the sheep; and 147.4 ± 5.7 μm, 446.1 ± 7.4 μm, 44.5 ± 5.0 μm, and 634.8 ± 6.2 μm, respectively, for the alpacas. Intraclass correlations ranged from 0.49 to 0.83 for CET, CST, and TCT and from 0.13 to 0.36 for DMT. CONCLUSIONS AND CLINICAL RELEVANCE SD-OCT provided manual measurement of corneal thickness (CET, CST, and TCT) with clinically acceptable intraoperator reliability for eyes of healthy goats, sheep, and alpacas.

OBJECTIVE To determine whether passive ureteral dilation (PUD) would occur after an indwelling ureteral stent was left in place in healthy dogs for 2 or 6 weeks, ureteroscopy would be possible at the time of stent removal, and PUD would be reversible after stent removal. ANIMALS 5 healthy adult female Beagles. PROCEDURES A ureteral stent was cystoscopically placed in each ureter of each dog with fluoroscopic guidance (week 0). One stent was removed from 1 ureter in each dog after 2 weeks (ureter group 1), and the other was removed after 6 weeks (ureter group 2); removal timing was randomized. Computed tomographic excretory urography was performed every 2 weeks from weeks 0 through 10 to measure ureteral diameters. Ureteroscopy was attempted at the time of ureteral stent removal in each group. Ureteral diameters were compared among measurement points. RESULTS The degree of PUD was significant after 2 and 6 weeks of stent placement in both ureter groups. Mean diameter of the midportion of the ureter in both groups prior to stent placement was 1.70 mm (range, 1.3 to 2.7 mm). At stent removal, mean diameter of the midportion of the ureter was 2.86 mm (range, 2.4 to 3.1 mm) in group 1 and 2.80 mm (range, 2.1 to 3.4 mm) in group 2. Ureteroscopy was successfully performed in all dogs up to the renal pelvis. Compared with week 0 values for diameter of the midportion of the ureter, the degree of PUD induced by stent placement had reversed by week 8 in group 1 (mean diameter, 2.00 mm [range, 1.5 to 2.3 mm]). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that ureteral stent placement for 2 weeks would result in sufficient PUD in healthy dogs to allow ureteroscopy at the time of stent removal and that the original ureteral diameter would eventually be restored. Additional research is needed to determine whether findings would be similar for dogs with urinary tract disease.

OBJECTIVE To compare intraosseous pentobarbital treatment (IPT) and thoracic compression (TC) on time to circulatory arrest and an isoelectric electroencephalogram (EEG) in anesthetized passerine birds. ANIMALS 30 wild-caught adult birds (17 house sparrows [Passer domesticus] and 13 European starlings [Sturnus vulgaris]). PROCEDURES Birds were assigned to receive IPT or TC (n = 6/species/group). Birds were anesthetized, and carotid arterial pulses were monitored by Doppler methodology. Five subdermal braided-wire electrodes were used for EEG. Anesthetic depth was adjusted until a continuous EEG pattern was maintained, then euthanasia was performed. Times from initiation of euthanasia to cessation of carotid pulse and irreversible isoelectric EEG (indicators of death) were measured. Data (medians and first to third quartiles) were summarized and compared between groups within species. Necropsies were performed for all birds included in experiments and for another 6 birds euthanized under anesthesia by TC (4 sparrows and 1 starling) or IPT (1 sparrow). RESULTS Median time to isoelectric EEG did not differ significantly between treatment groups for sparrows (19.0 and 6.0 seconds for TC and IPT, respectively) or starlings (88.5 and 77.5 seconds for TC and IPT, respectively). Median times to cessation of pulse were significantly shorter for TC than for IPT in sparrows (0.0 vs 18.5 seconds) and starlings (9.5 vs 151.0 seconds). On necropsy, most (14/17) birds that underwent TC had grossly visible coelomic, pericardial, or perihepatic hemorrhage. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that TC might be an efficient euthanasia method for small birds. Digital pressure directly over the heart during TC obstructed venous return, causing rapid circulatory arrest, with rupture of the atria or vena cava in several birds. The authors propose that cardiac compression is a more accurate description than TC for this procedure.

OBJECTIVE To determine the pharmacokinetics of meloxicam in domestic hens and duration and quantity of drug residues in their eggs following PO administration of a single dose (1 mg of meloxicam/kg). ANIMALS 8 healthy adult White Leghorn hens. PROCEDURES Hens were administered 1 mg of meloxicam/kg PO once. A blood sample was collected immediately before and at intervals up to 48 hours after drug administration. The hens' eggs were collected for 3 weeks after drug administration. Samples of the hens' plasma, egg whites (albumen), and egg yolks were analyzed by high-performance liquid chromatography. RESULTS The half-life, maximum concentration, and time to maximum concentration of meloxicam in plasma samples were 2.8 hours, 7.21 μg/mL, and 2 hours, respectively. Following meloxicam administration, the drug was not detected after 4 days in egg whites and after 8 days in egg yolks. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that meloxicam administered at a dose of 1 mg/kg PO in chickens appears to maintain plasma concentrations equivalent to those reported to be therapeutic for humans for 12 hours. The egg residue data may be used to aid establishment of appropriate drug withdrawal time recommendations.

OBJECTIVE To investigate the use of canine whole blood (WB) for measurement of ammonia concentration by use of a point-of-care ammonia meter and to compare results of measuring ammonia concentrations in WB, EDTA-anticoagulated WB, and plasma. ANIMALS 40 client-owned dogs. PROCEDURES A blood sample (2 mL) was obtained from each dog. One drop of WB was immediately applied to a test strip for evaluation with an ammonia meter. The remainder of the blood sample was placed in an EDTA-containing tube, and 1 drop of EDTA-anticoagulated WB was applied to a test strip. The remaining EDTA-anticoagulated WB sample was centrifuged, and the plasma was harvested and placed on ice. One drop of plasma was applied to a test strip; the remainder of the plasma sample was transported on ice and used for ammonia measurement with a reference laboratory instrument. All samples were tested within 1 hour after sample collection. Results were evaluated to detect significant differences in ammonia concentration. RESULTS Ammonia concentrations did not differ significantly between WB and EDTA-anticoagulated WB and between plasma samples measured with the meter and reference laboratory instrument. However, median ammonia concentration was significantly higher in plasma than in WB or EDTA-anti-coagulated WB. CONCLUSIONS AND CLINICAL RELEVANCE Anticoagulant-free WB was a valid sample for measurement by use of the ammonia meter. Plasma samples had higher ammonia concentrations than did WB samples. Results for each sample type should be interpreted by use of specimen- and method-specific reference intervals.

OBJECTIVE To characterize the maternal and fetal cardiopulmonary effects of a low-dose infusion of dexmedetomidine without a loading dose in pregnant ewes anesthetized with sevoflurane. ANIMALS 11 pregnant ewes. PROCEDURES Anesthesia was induced with propofol and maintained with sevoflurane. Ewes and fetuses were instrumented with arterial and venous catheters, and thermodilution–pulmonary arterial catheters were placed in the ewes. Baseline measurements were obtained at an end-tidal sevoflurane concentration of 3.4%, then dexmedetomidine (2 μg/kg/h, IV) was infused for 90 minutes without a loading dose. Cardiovascular and blood gas variables were measured at predetermined time points. RESULTS Dexmedetomidine infusion resulted in approximately 30% decreases in maternal systemic vascular resistance, blood pressure, and heart rate. Maternal cardiac index, oxygenation variables, and acid-base status remained unchanged, whereas pulmonary arterial pressure, pulmonary vascular resistance, and stroke volume increased, compared with baseline values. Uterine blood flow decreased by approximately 30% to 36%. Fetal heart rate and blood pressure remained unchanged, but significant increases in fetal plasma glucose and lactate concentrations were detected. CONCLUSIONS AND CLINICAL RELEVANCE Pregnant ewes receiving a combination of sevoflurane and an infusion of dexmedetomidine without a loading dose had cardiac index in acceptable ranges and maintained normoxia. This balanced anesthesia did not produce significant changes in fetal blood pressure or heart rate. However, the increase in fetal plasma lactate concentration and changes in maternal pulmonary vascular resistance and uterine blood flow require further investigation to better elucidate these effects.

OBJECTIVE To determine titers of serum antibodies against 3 genotypes of bovine parainfluenza 3 virus (BPI3V) in unvaccinated ungulates in Alabama. ANIMALS 62 cattle, goats, and New World camelids from 5 distinct herds and 21 captured white-tailed deer. PROCEDURES Serum samples were obtained from all animals for determination of anti-BPI3V antibody titers, which were measured by virus neutralization assays that used indicator (reference) viruses from each of the 3 BPI3V genotypes (BPI3V-A, BPI3V-B, and BPI3V-C). The reference strains were recent clinical isolates from US cattle. Each sample was assayed in triplicate for each genotype. Animals with a mean antibody titer = 2 for a particular genotype were considered seronegative for that genotype. RESULTS Animals seropositive for antibodies against BPI3V were identified in 2 of 3 groups of cattle and the group of New World camelids. The geometric mean antibody titer against BPI3V-B was significantly greater than that for BPI3V-A and BPI3V-C in all 3 groups. All goats, captive white-tailed deer, and cattle in the third cattle group were seronegative for all 3 genotypes of the virus. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that BPI3V-A may no longer be the predominant genotype circulating among ungulates in Alabama. This may be clinically relevant because BPI3V is frequently involved in the pathogenesis of bovine respiratory disease complex, current vaccines contain antigens against BPI3V-A only, and the extent of cross-protection among antibodies against the various BPI3V genotypes is unknown.

OBJECTIVE To evaluate the accuracy of cardiac output (CO) estimated by use of ECG-gated multidetector CT (MDCT) and 1-, 2-, and 3-D echocardiography and by use of thermodilution. ANIMALS 6 healthy hound-cross dogs. PROCEDURES Electrocardiogram-gated contrast-enhanced 64-slice MDCT and 1-, 2-, and 3-D echocardiography were performed on each dog. The CO for ECG-gated MDCT was calculated as volumetric measurements of stroke volume multiplied by mean heart rate. Echocardiographic left ventricle end-diastolic volumes and end-systolic volumes were measured by use of the Teichholz method (1-D echocardiography) and a single-plane method of disks (2-D echocardiography). Real-time 3-D echocardiographic left ventricle volumes were measured with 3-D functional analysis software on right long-axis and left apical views. The CO of each dog was measured in triplicate by use of thermodilution. Mean CO values, correlations, and limits of agreement for MDCT, echocardiographic modalities, and thermodilution were compared. RESULTS CO measured by use of MDCT, 2-D echocardiography, and 3-D echocardiography had the strongest correlations with CO measured by use of thermodilution. No significant difference in CO was detected between MDCT, any echocardiographic method, and thermodilution. Bland-Altman analysis revealed a systematic underestimation of CO derived by use of MDCT, 2-D echocardiography, and 3-D echocardiography. CONCLUSIONS AND CLINICAL RELEVANCE Use of MDCT, 2-D echocardiography, and 3-D echocardiography to measure CO in healthy dogs was feasible. Measures of CO determined by use of 3-D echocardiography on the right long-axis view were strongly correlated with CO determined by use of thermodilution, with little variance and slight underestimation.