Objective-To evaluate respiratory mechanical function and bronchoalveolar lavage (BAL) cytologic results in healthy alpacas. Animals-16 client-owned adult alpacas. Procedures-Measurements of pulmonary function were performed, including functional residual capacity (FRC) via helium dilution, respiratory system resistance via forced oscillatory technique (FOT), and assessment of breathing pattern by use of respiratory inductive plethysmography (RIP) in standing and sternally recumbent alpacas. Bronchoalveolar lavage was performed orotracheally during short-term anesthesia. Results-Mean +/- SD measurements of respiratory function were obtained in standing alpacas for FRC (3.19 +/- 0.53 L), tidal volume (0.8 +/- 0.13 L), and respiratory system resistance at 1 Hz (2.70 +/- 0.88 cm H2O/L/s), 2 Hz (2.98 +/- 0.70 cm H2O/L/s), 3 Hz (3.14 +/- 0.77 cm H2O/L/s), 5 Hz (3.45 +/- 0.91 cm H2O/L/s), and 7 Hz (3.84 +/- 0.93 cm H2O/L/s). Mean phase angle, as a measurement of thoracoabdominal asynchrony, was 19.59 +/- 10.06°, and mean difference between nasal and plethysmographic flow measurements was 0.18 +/- 0.07 L/s. Tidal volume, peak inspiratory flow, and peak expiratory flow were significantly higher in sternally recumbent alpacas than in standing alpacas. Cytologic examination of BAL fluid revealed 58.52 +/- 12.36% alveolar macrophages, 30.53 +/- 13.78% lymphocytes, 10.95 +/- 9.29% neutrophils, 0% mast cells, and several ciliated epithelial cells. Conclusions and Clinical Relevance-Pulmonary function testing was tolerated well in nonsedated untrained alpacas. Bronchoalveolar lavage in alpacas yielded samples with adequate cellularity that had a greater abundance of neutrophils than has been reported in horses.

Previously we described the development of an attenuated Pasteurella multocida mutant that expresses only the N-terminal truncated fragment of P. multocida toxin (N-PMT) and its protective effects in a mouse model. This paper details our evaluation of the vaccine potential of this mutant strain in pigs. Pigs vaccinated with the mutant showed significantly higher rates of antibody induction and lower nasal conchal (turbinate) scores for atrophic rhinitis than controls, which suggests that this mutant strain may be a good candidate for a live attenuated vaccine.

This cross-sectional clinical study compared inflammation, including expression of the chemokine interleukin (IL)-8 and intercellular cell adhesion molecule-1 (ICAM-1), in the stifle joints of 4 control dogs and 23 dogs with cranial cruciate ligament rupture (CCLR). The CCL, synovial membrane, meniscus, cartilage, and synovial fluid from the affected stifle joints of all the dogs were examined. Inflammatory cell counts were performed on the synovial fluid, and the tissues were processed for histologic study and immunohistochemical detection of IL-8 and ICAM-1. The synovial fluid from the stifle joints of the dogs with CCLR had an increased percentage of neutrophils (P = 0.054) and a decreased percentage of lymphocytes (P = 0.004) but not macrophages compared with the fluid from the control dogs. There was accumulation of inflammatory cells and increased expression of IL-8 and ICAM-1 in the vascular endothelium of the synovial membrane and the CCL of the dogs with CCLR. The increase in inflammatory cells in the stifle joints of dogs with CCLR may therefore be due to increased expression of IL-8 and ICAM-1 in the synovial membrane and the CCL after the injury. These data may help in understanding the mechanisms of inflammation associated with CCLR.

The objective of this study was to determine whether post-vaccination antibody titers vary according to body weight in adult dogs. Antibody titers against canine parvovirus type 2 (CPV-2), canine distemper virus (CDV), and canine adenovirus type 1 (CAdV-1) were measured for 978 domestic adult dogs from 2 to 6 y of age. The dogs had been vaccinated approximately 12 mo earlier with a commercial combination vaccine. The dogs were divided into groups according to their weight. It was found that mean antibody titers in all weight groups were sufficient to prevent infection. Intergroup comparison, however, revealed that CPV-2 antibody titers were significantly higher in the Super Light (< 5 kg) group than in the Medium (10 to 19.9 kg) and Heavy (> 20 kg) groups and were also significantly higher in the Light (5 to 9.9 kg) group than in the Heavy group. Antibody titers against CDV were significantly higher in the Super Light, Light, and Medium groups than in the Heavy group. There were no significant differences among the groups for the CAdV-1 antibody titers.

Objective: To identify gait characteristics during trotting on a treadmill in nonlame Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease (CCLD). Animals: Clinically normal Labrador Retrievers presumed predisposed (n = 10) or not predisposed (7) to CCLD. Procedures: The right hind limb of each dog was classified by use of a predictive score equation that combined tibial plateau angle and femoral anteversion angle as presumed predisposed (high score [> −1.5]) or not predisposed (low score [≤ −1.5]) to CCLD. Tarsal joint, stifle joint, and hip joint kinematics, net moments, and powers were computed. Results: The stifle joint was held at a greater degree of flexion in limbs presumed predisposed to CCLD (130.9° vs 139.3°). More power was generated by muscles acting on the stifle joint in the early stance phase of limbs presumed to be predisposed to CCLD (2.93 vs 1.64 W/kg). The tarsal joint did not reach the same degree of extension in limbs presumed predisposed to CCLD, compared with that in limbs presumed not predisposed to CCLD (179.0° vs 161.0°). Velocity, stance time, vertical and craniocaudal forces, angular velocities, and net joint muscle moments did not differ between groups. Conclusions and Clinical Relevance: Gait mechanics of dogs with high (> −1.5) and low (≤ −1.5) tibial plateau angle and femoral anteversion angle scores were characterized on a treadmill, which may help in the identification of dogs predisposed to CCLD.

Objective: To investigate the influence of dietary supplementation with l-carnitine on metabolic rate, fatty acid oxidation, weight loss, and lean body mass (LBM) in overweight cats undergoing rapid weight reduction. Animals: 32 healthy adult neutered colony-housed cats. Procedures: Cats fattened through unrestricted ingestion of an energy-dense diet for 6 months were randomly assigned to 4 groups and fed a weight reduction diet supplemented with 0 (control), 50, 100, or 150 μg of carnitine/g of diet (unrestricted for 1 month, then restricted). Measurements included resting energy expenditure, respiratory quotient, daily energy expenditure, LBM, and fatty acid oxidation. Following weight loss, cats were allowed unrestricted feeding of the energy-dense diet to investigate weight gain after test diet cessation. Results: Median weekly weight loss in all groups was ≥ 1.3%, with no difference among groups in overall or cumulative percentage weight loss. During restricted feeding, the resting energy expenditure-to-LBM ratio was significantly higher in cats that received l-carnitine than in those that received the control diet. Respiratory quotient was significantly lower in each cat that received l-carnitine on day 42, compared with the value before the diet began, and in all cats that received l-carnitine, compared with the control group throughout restricted feeding. A significant increase in palmitate flux rate in cats fed the diet with 150 μg of carnitine/g relative to the flux rate in the control group on day 42 corresponded to significantly increased stoichiometric fat oxidation in the l-carnitine diet group (> 62% vs 14% for the control group). Weight gain (as high as 28%) was evident within 35 days after unrestricted feeding was reintroduced. Conclusions and Clinical Relevance: Dietary l-carnitine supplementation appeared to have a metabolic effect in overweight cats undergoing rapid weight loss that facilitated fatty acid oxidation.

Objective-To measure the effects of tidal volume, ventilatory frequency, and oxygen insufflation flow on the fraction of inspired oxygen in cadaveric horse heads attached to a lung model. Sample-8 heads of equine cadavers. Procedures-Each cadaveric horse head was intubated with a nasotracheal tube that extended into the proximal portion of the trachea. Oxygen was delivered through an oxygen catheter contained within and extending to the tip of the nasotracheal tube. The trachea was connected to the lung model by use of a spiral-wound hose with a sampling adaptor. Eight treatment combinations involving 2 tidal volumes (5 and 8 L), 2 ventilatory frequencies (6 and 12 mechanical breathes/min), and 2 insufflation rates (10 and 15 L/min) were applied to each head. Hand-drawn inspired gas samples were collected and analyzed for oxygen concentrations. Results-The fraction of inspired oxygen (measured at mid trachea) ranged from 26.8% to 39.4%. Fraction of inspired oxygen was significantly higher with a smaller tidal volume, lower ventilatory frequency, and higher insufflation rate. Conclusions and Clinical Relevance-In the study model, measured fraction of inspired oxygen varied with ventilatory pattern as well as oxygen insufflation rate. Clinically, this information could be beneficial for interpretation of data regarding arterial blood gases and hemoglobin saturation and in making appropriate oxygen insufflation decisions for anesthetized horses that are breathing room air.

Objective-To compare in vitro expansion of equine tendon- and bone marrow–derived cells with fibroblast growth factor-2 (FGF-2) supplementation and sequential matrix synthesis with pulverized tendon and insulin-like growth factor-I (IGF-I). Sample-Cells from 6 young adult horses. Procedures-Progenitor cells were expanded in monolayers with FGF-2, followed by culture with autogenous acellular pulverized tendon and IGF-I for 7 days. Initial cell isolation and subsequent monolayer proliferation were assessed. In pulverized tendon cultures, cell viability and expression of collagen types I and III and cartilage oligomeric matrix protein (COMP) mRNAs were assessed. Collagen and glycosaminoglycan syntheses were quantified over a 24-hour period. Results-Monolayer expansion with FGF-2 significantly increased the mean +/- SE number of tendon-derived cells (15.3 +/- 2.6 × 10(6)), compared with bone marrow-derived cells (5.8 +/- 1.8 × 10(6)). Overall, increases in collagen type III and COMP mRNAs were seen in tendon-derived cells, compared with results for bone marrow-derived cells. After IGF-I supplementation, increases in collagen type I and type III mRNA expression were seen in bone marrow–derived cells, compared with results for unsupplemented control cells. Insulin-like growth factor-I significantly increased collagen synthesis of bone marrow–derived cells. Monolayer expansion with FGF-2 followed by IGF-I supplementation significantly increased glycosaminoglycan synthesis in tendon-derived cells. Conclusions and Clinical Relevance-Tendon-derived cells had increased cell numbers and matrix synthesis after monolayer expansion with FGF-2, compared with results for bone marrow–derived cells. In vivo experiments with FGF-2-expanded tendon-derived cells are warranted to evaluate effects on tendon healing.

Objective: To investigate contrast-enhanced ultrasonography as a minimally invasive method for the subjective and quantitative assessment of pancreatic and duodenal perfusion in healthy adult dogs, with reference to perfusion in adjacent liver tissue. Animals: 8 clinically normal adult dogs. Procedures: Contrast-enhanced ultrasonograms of the right pancreatic limb, proximal portion of the descending duodenum, and adjacent liver were acquired after IV administration of a microbubble contrast medium. Following subjective evaluation, quantitative time-intensity curves were generated from regions of interest in the pancreas, duodenum, and liver. Five contrast medium characteristics representing perfusion parameters were determined for each organ and used for statistical analysis: interval to arrival, inflow rate, peak intensity (PI), time of peak intensity (TPI), and outflow rate. Results: Significant associations between pancreatic and duodenal values were found for interval to contrast medium arrival, PI, TPI, and outflow rate. Pancreatic and duodenal inflow rates were not correlated. Inflow and outflow rates were significantly faster and TPI significantly shorter for the pancreas and duodenum, compared with values for the liver. There was no significant difference among all 3 organs for interval to arrival and PI of contrast medium. Subjective evaluation findings corresponded to quantitative analysis results. Conclusions and Clinical Relevance: Results suggested that contrast-enhanced ultrasonography may be a useful, minimally invasive method for evaluating pancreatic and duodenal perfusion in dogs. The data from healthy dogs reported here could aid in the assessment of pancreatic and duodenal conditions and their response to medical treatment.

Objective: To compare the axial stiffness, maximum axial displacement, and ring deformation during axial loading of single complete and incomplete circular (ring) external skeletal fixator constructs. Sample: 32 groups of single ring constructs (5 constructs/group). Procedures: Single ring constructs assembled with 2 divergent 1.6-mm-diameter Kirschner wires were used to stabilize a 60-mm-long segment of 16-mm-diameter acetyl resin rod. Construct variables included ring type (complete or incomplete), ring diameter (50, 66, 84, or 118 mm), and fixation wire tension (0, 30, 60, or 90 kg). Axial loading was performed with a materials testing system. Construct secant stiffness and maximum displacement were calculated from the load-displacement curves generated for each construct. Ring deformation was calculated by comparing ring diameter during and after construct loading to ring diameter prior to testing. Results: Complete ring constructs had greater axial stiffness than did the 66-, 84-, and 118-mm-diameter incomplete ring constructs. As fixation wire tension increased, construct stiffness increased in the 66-, 84-, and 118-mm-diameter incomplete ring constructs. Maximum axial displacement decreased with increasing fixation wire tension, and complete ring constructs allowed less displacement than did incomplete ring constructs. Incomplete rings were deformed by wire tensioning and construct loading. Conclusions and Clinical Relevance: Mechanical performance of the 66-, 84-, and 118-mm-diameter incomplete ring constructs improved when wire tension was applied, but these constructs were not as stiff as and allowed greater displacement than did complete ring constructs of comparable diameter. For clinical practice, tensioning the wires placed on 84- and 118-mm-diameter incomplete rings to 60 kg is recommended.