The objective of this study was to develop a time-resolved immunofluorometric assay (TR-IFMA) for quantification of salivary alpha-amylase in sheep. For that purpose, after the design of the assay, an analytical and a clinical validation were carried out. The analytical validation of the assay showed intra- and inter-assay coefficients of variation (CVs) of 6.1% and 10.57%, respectively and an analytical limit of detection of 0.09 ng/mL. The assay also demonstrated a high level of accuracy, as determined by linearity under dilution. For clinical validation, a model of acute stress testing was conducted to determine whether expected significant changes in alpha-amylase were picked up in the newly developed assay. In that model, 11 sheep were immobilized and confronted with a sheepdog to induce stress. Saliva samples were obtained before stress induction and 15, 30, and 60 min afterwards. Salivary cortisol was measured as a reference of stress level. The results of TR-IFMA showed a significant increase (P < 0.01) in the concentration of alpha-amylase in saliva after stress induction. The assay developed in this study could be used to measure salivary alpha-amylase in the saliva of sheep and this enzyme could be a possible noninvasive biomarker of stress in sheep.

OBJECTIVE To compare humoral insulin-like growth factor (IGF)-1, platelet-derived growth factor (PDGF)-BB, transforming growth factor (TGF)-β1, and interleukin-1 receptor antagonist (IL-1Ra) concentrations in plasma and 3 types of equine autologous blood-derived preparations (ABPs). SAMPLE Blood and ABP samples from 12 horses. PROCEDURES Blood samples from each horse were processed by use of commercial systems to obtain plasma, platelet concentrate, conditioned serum, and aqueous platelet lysate. Half of the platelet concentrate samples were additionally treated with a detergent to release intracellular mediators. Humoral IGF-1, PDGF-BB, TGF-β1, and IL-1Ra concentrations were measured with ELISAs and compared statistically. RESULTS Median IGF-1 concentration was highest in conditioned serum and detergent-treated platelet concentrate, followed by platelet concentrate and plasma; IGF-1 was not detected in platelet lysate. Mean PDGF-BB concentration was highest in platelet lysate, followed by detergent-treated platelet concentrate and conditioned serum; PDGF-BB was not detected in plasma and platelet concentrate. Median TGF-β1 concentration was highest in detergent-treated platelet concentrate, followed by conditioned serum, platelet lysate, and platelet concentrate; TGF-β1 was not detected in most plasma samples. Median IL-1Ra concentration was highest in platelet lysate, followed by conditioned serum; IL-1Ra was not detected in almost all plasma, detergent-treated platelet concentrate, and platelet concentrate samples. CONCLUSIONS AND CLINICAL RELEVANCE Each ABP had its own cytokine profile, which was determined by the specific processing method. Coagulation and cellular lysis strongly increased humoral concentrations of cell-derived cytokines. No ABP had the highest concentrations for all cytokines. Further studies are needed to assess clinical relevance of these findings.

OBJECTIVE To evaluate the effects of treatment of horses with standard platelet inhibitors on ex vivo inhibition of platelet activation by equine herpesvirus type I (EHV-I). ANIMALS II healthy adult horses. PROCEDURES In a double-blinded, placebo-controlled crossover study, horses were treated orally for 5 days with theophylline (5 mg/kg, q 12 h), pentoxifylline (10 mg/kg, q 12 h), clopidogrel bisulfate (4 mg/kg, q 24 h), acetylsalicylic acid (20 mg/kg, q 24 h), or placebo. Horses received all treatments, each separated by a 3-week washout period. Platelet-rich plasma was prepared from citrated blood samples obtained before each treatment session and 4 hours after each final drug dose. Platelets were exposed to 2 EHV-I strains (at I plaque forming units/cell) or positive (thrombin-convulxin) and negative control substances for 10 minutes, then platelet activation was assessed by determining the percentages of P-selectin–positive platelets and platelet-derived microparticles (PDMPs; small events positive for annexin V) with flow cytometry. Platelet aggregation in response to 10μM ADP was also assessed. RESULTS No significant differences in median percentages of P-selectin–positive platelets and PDMPs in EHV-I-exposed platelets were identified between measurement points (before and after treatment) for all drugs, nor were differences identified among drugs at each measurement point. Only clopidogrel significantly inhibited platelet aggregation in response to ADP in platelet-rich plasma samples obtained after that treatment session. CONCLUSIONS AND CLINICAL RELEVANCE Treatment of horses with standard platelet inhibitors had no effect on EHV-I-induced platelet α-granule exteriorization or microvesiculation and release of PDMPs ex vivo, suggesting these drugs will not prevent platelet activation induced directly by EHV-I in vivo.

OBJECTIVE To determine the prevalence of naturally occurring anti-dog erythrocyte antigen (DEA) 7 antibodies in DEA 7–negative dogs from Spain and Italy. ANIMALS 252 DEA 7–negative dogs from a population of 312 dogs that were previously tested for DEA 1, DEA 4, and DEA 7. PROCEDURES A plasma sample was obtained from each dog and evaluated for anti-DEA 7 antibodies by the use of gel column agglutination. Each plasma sample underwent major crossmatching with RBCs from DEA 7-positive dogs. Samples that resulted in agglutination were then crossmatched with RBCs from DEA 1-negative, DEA 4-positive, and DEA 7–negative dogs to confirm the presence of anti-DEA 7 antibodies. Results were then used to calculate the risk for a delayed transfusion reaction in a DEA 7–negative dog with anti-DEA 7 antibodies after a transfusion with blood that was not crossmatched or typed for DEA 7. RESULTS 96 of 252 (38.1%) plasma samples contained anti-DEA 7 antibodies. A DEA 7–negative dog with anti-DEA 7 antibodies had a 5.9% chance of developing a delayed hemolytic reaction after transfusion with blood not crossmatched or typed for DEA 7. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that canine blood used for transfusion should be crossmatched with the blood or plasma of the intended recipient prior to transfusion to minimize the likelihood that the recipient will develop a hemolytic reaction associated with anti-DEA 7 antibodies. Ideal canine blood donors should be negative for both DEA 1 and DEA 7.

OBJECTIVE To determine the pharmacokinetics of meloxicam after single IV and IM injections in red-eared slider turtles (Trachemys scripta elegans). ANIMALS 8 healthy red-eared slider turtles. PROCEDURES Turtles received 1 dose of meloxicam (0.2 mg/kg) IV or IM (4 turtles/route), a 30-day washout period was provided, and then turtles received the same dose by the opposite route. Blood samples were collected at predetermined times for measurement of plasma meloxicam concentration. Pharmacokinetic values for each administration route were determined with a 2-compartment open model approach. RESULTS For IV administration, mean ± SD values of major pharmacokinetic variables were 1.02 ± 0.41 hours for distribution half-life, 9.78 ± 2.23 hours for elimination half-life, 215 ± 32 mL/kg for volume of distribution at steady state, 11.27 ± 1.44 μg•h/mL for area under the plasma concentration versus time curve, and 18.00 ± 2.32 mL/h/kg for total body clearance. For IM administration, mean values were 0.35 ± 0.06 hours for absorption half-life, 0.72 ± 0.06 μg/mL for peak plasma concentration, 1.5 ± 0.0 hours for time to peak concentration, 3.73 ± 2.41 hours for distribution half-life, 13.53 ± 1.95 hours for elimination half-life, 11.33 ± 0.92 μg•h/mL for area under the plasma concentration versus time curve, and 101 ± 6% for bioavailability. No adverse reactions were detected. CONCLUSIONS AND CLINICAL RELEVANCE Long half-life, high bioavailability, and lack of immediate adverse reactions of meloxicam administered IM at 0.2 mg/kg suggested the possibility of safe and effective clinical use in turtles. Additional studies are needed to establish appropriate administration frequency and clinical efficacy.

OBJECTIVE To determine the effects of racetrack surface and shoe characteristics on formation of wear grooves in the horseshoes of racehorses. SAMPLES 1,121 horseshoes from 242 Thoroughbred racehorses collected during routine horseshoeing procedures at 4 racetracks with dirt or synthetic surfaces. PROCEDURES Data for 1,014 horseshoes from 233 racehorses were analyzed. Horseshoes were photographed, and length and width of grooves formed at the heels of the solar surface of horseshoes were measured on the photographs. Effects of racetrack, racetrack surface, and shoe characteristics (eg, shoe size, clips, and nails) on length and width of grooves were assessed by use of a mixed-model anova. RESULTS Length and width of wear grooves differed significantly on the basis of racetrack, nail placement, and limb side (left vs right). Differences in groove dimensions between types of racetrack surface (dirt vs synthetic) were less apparent than differences among racetracks. CONCLUSIONS AND CLINICAL RELEVANCE Measurements of the length and width of wear grooves in the horseshoes of racehorses may be useful for understanding some aspects of hoof interactions with various racetrack surfaces. Interpretation of differences in wear grooves for various racetrack surfaces will likely require quantitation of the mechanical behavior of the surfaces.

OBJECTIVE To compare gene expression patterns of T cells in porcine colostrum and peripheral blood. ANIMALS 10 multiparous sows. PROCEDURES Cytotoxic and CD4-CD8 double-positive T cells were separated from porcine colostrum and peripheral blood. Total RNA was extracted. The cDNA prepared from RNA was amplified, labeled, fragmented, and competitively hybridized to DNA microarray slides. The DNA microarray data were validated by use of a real-time reverse-transcription PCR assay, and expression of the genes FOS, NFKBI, IFNG, CXCR6, CCR5, ITGB2, CCR7, and SELL was assessed. Finally, DNA microarray data were validated at the protein level by use of flow cytometry via expression of c-Fos and integrin β-2. RESULTS Evaluation of gene expression profiles indicated that in contrast to results for peripheral blood, numerous cell-signaling pathways might be activated in colostrum. Profile analysis also revealed that FOS and NFKBI (genes of transcription factors) were involved in most cell-signaling pathways and that expression of these genes was significantly higher in colostral T cells than in peripheral blood T cells. Furthermore, CCR7 and SELL (genes of T-cell differentiation markers) in colostral T cells had expression patterns extremely similar to those found in effector or effector memory T cells. CONCLUSIONS AND CLINICAL RELEVANCE All or most of the T cells in colostrum had an effector-like phenotype and thus were more activated than those in peripheral blood. This gene expression profile would enable T cells to migrate to mammary glands, be secreted in colostrum, and likely contribute to passive immunity provided by sows to newborn pigs.

The objective of this study was to evaluate the stability of 3 distinct preparations of ketamine and xylazine, with or without acepromazine, stored at room temperature or at 4°C for 1, 2, and 3 mo. Drug concentrations were compared to fresh solutions, using a high performance liquid chromatography-mass spectrometry/selected-ion monitoring (HPLC-MS/SIM) assay. The concentrations of ketamine and xylazine, diluted in physiological saline, did not change over time at room temperature or at 4°C. However, acepromazine concentrations decreased over time when stored at room temperature. In contrast, undiluted ketamine-xylazine preparations gradually decreased in concentration when stored at room temperature. All of the drug concentrations remained above 90% of their original concentration when stored at 4°C. In conclusion, when diluted in physiological saline, ketamine-xylazine cocktails can be stored for 3 mo, whereas undiluted cocktails can lose efficacy over 3 mo at room temperature. Storage at 4°C could preserve drug stability.

OBJECTIVE To evaluate the effects of successive large-segment tracheal resection and anastomosis on tracheal diameter and position of lobar bronchi in dogs. ANIMALS 5 adult Beagles. PROCEDURES Right lateral radiographs were obtained for all dogs and used to measure tracheal length. Dogs were then euthanized, and successive segmental tracheal resections (intervals of 10% from 20% to 50% of the tracheal length), each of which was followed by anastomosis, were performed in each cadaver. Tracheobronchoscopy was performed before the first tracheal resection and after each of the anastomoses to evaluate tracheal diameter and changes in position of lobar bronchi. RESULTS Tracheal diameter was minimally affected by resections up to 50% of the tracheal length. Diameter of the trachea and position of bronchi were not affected by resection of 20% of the tracheal length. Changes in the position of various lobar bronchi were detected after resection of 30% of the tracheal length. CONCLUSIONS AND CLINCIAL RELEVANCE In this study, tracheal resections of 20% of the tracheal length were accommodated, possibly as a result of stretching of the annular ligament. Resections of ≥ 30% of the tracheal length altered the position of lobar bronchi. Clinical effects, if any, attributable to these changes in bronchial position remain to be elucidated.

OBJECTIVE To determine the effect of repeated gas sterilization on rate of closure of ameroid ring constrictors in vitro. SAMPLE Twenty-four 3.5-mm ameroid ring constrictors. PROCEDURES Ameroid ring constrictors were allocated to 1 of 4 treatment groups (6/group) to undergo gas sterilization 0, 1, 5, or 10 times. After sterilization, constrictors were incubated in canine plasma at a protein concentration of 3 g/dL for 27 days. A digital camera was used to obtain images of the constrictors prior to and at various points during incubation, and lumen diameter was measured. RESULTS Mean ± SD percentage of lumen closure for all groups of ameroid ring constrictors combined was 85.2 ± 1.6% at day 0 (prior to plasma incubation) and 95.4 ± 0.8% at day 27. Mean lumen area was 3.64 ± 0.43 mm2 (95% confidence interval, 2.67 to 4.77 mm2) at day 0 and 1.32 ± 0.25 mm2 (95% confidence interval, 0.76 to 2.04 mm2) at day 27. None of the ameroid ring constrictors had closed completely by day 27. CONCLUSIONS AND CLINICAL RELEVANCE Overall closure rates for ameroid ring constrictors appeared to be unaffected by repeated gas sterilization up to 10 times. Findings suggested that veterinary surgeons can resterilize ameroid ring constrictors up to 10 times with confidence that ring properties would remain suitable for clinical use.