Objective: To assess the transmission of bovine viral diarrhea virus (BVDV) from experimentally infected white-tailed deer fawns to colostrum-deprived calves by use of a BVDV strain isolated from hunter-harvested white-tailed deer. Animals: 5 white-tailed deer (Odocoileus virginianus) fawns and 6 colostrum-deprived calves. Procedures: Fawns were inoculated intranasally with a noncytopathic BVDV-1a isolate (2 mL containing 10(6.7) TCID(50)/mL), and 2 days after inoculation, animals were commingled until the end of the study. Blood and serum samples were obtained on days −6, 0, 7, 14, and 21 after inoculation for reverse transcriptase PCR assay, virus neutralization, and BVDV-specific antibody ELISA. Nasal, oral, and rectal swab specimens were collected on days 0, 3, 7, 14, 17, and 21 for reverse transcriptase PCR testing. By 21 days after inoculation, all animals were euthanized and necropsied and tissues were collected for histologic evaluation, immunohistochemical analysis, and virus isolation. Results: All fawns became infected and shed the virus for up to 18 days as determined on the basis of reverse transcriptase PCR testing and virus isolation results. Evidence of BVDV infection as a result of cohabitation with acutely infected fawns was detected in 4 of the 6 calves by means of reverse transcriptase PCR testing and virus isolation. Conclusions and Clinical Relevance: On the basis of these findings, BVDV transmission from acutely infected fawns to colostrum-deprived calves appeared possible.

Objective: To evaluate the effects of the pacemaker funny current (If) inhibitor ivabradine on heart rate (HR), left ventricular (LV) systolic and diastolic function, and left atrial performance in healthy cats and cats with hypertrophic cardiomyopathy (HCM). Animals: 6 healthy cats and 6 cats with subclinical HCM. Procedures: Anesthetized cats underwent cardiac catheterization and were studied over a range of hemodynamic states induced by treatment with esmolol (200 to 400 μg/kg/min, IV), esmolol and dobutamine (5 μg/kg/min, IV), ivabradine (0.3 mg/kg, IV), and ivabradine and dobutamine. Left ventricular systolic and diastolic function, cardiac output, and left atrial function were studied via catheter-based methods and echocardiography. Results: Treatment with ivabradine resulted in a significant reduction of HR, rate-pressure product, and LV contractile function and a significant increase in LV end-diastolic pressure, LV end-diastolic wall stress, and LV relaxation time constant (tau) in cats with HCM. Concurrent administration of ivabradine and dobutamine resulted in a significant increase of LV contractility and lusitropy, with blunted chronotropic effects of the catecholamine. Left atrial performance was not significantly altered by ivabradine in cats with HCM. Regression analysis revealed an association between maximum rate of LV pressure rise and tau in cats with HCM. Conclusions and Clinical Relevance: Ivabradine had significant effects on several cardiovascular variables in anesthetized cats with HCM. Studies in awake cats with HCM are needed to clinically validate these findings.

Objective: To determine the oncolytic efficacy of an attenuated form of myxoma virus lacking the serp2 gene in canine tumor cells. Sample: Primary cells were isolated from tumors that were surgically removed from dogs and from connective tissue obtained from the cadaver of a dog. Cells of various established cell lines from tumors and nontumorous tissues were obtained. Procedures: Experiments were performed with cells in monolayer culture. Cell cultures were inoculated with wild-type myxoma viruses or myxoma viruses lacking the serp2 gene, and measures of cytopathic effects, viral growth kinetics, and cell death and apoptosis were determined. Results: Myxoma viruses replicated in cells of many of the primary and established canine tumor cell lines. Canine tumor cells in which expression of activated protein kinase B was upregulated were more permissive to myxoma virus infection than were cells in which expression of activated protein kinase B was not upregulated. Myxoma viruses lacking the serp2 gene caused more cytopathic effects in canine tumor cells because of apoptosis than did wild-type myxoma viruses. Conclusions and Clinical Relevance: Results of the present study indicated myxoma viruses lacking the serp2 gene may be useful for treatment of cancer in dogs. Impact for Human Medicine: Results of the present study may be useful for development of novel oncolytic treatments for tumors in humans.

Objective: To evaluate perineal analgesic effects of 3 doses of neostigmine coadministered epidurally with lidocaine to geldings. Animals: 6 healthy geldings. Procedures: A few days before each treatment, a catheter was inserted between the first and second coccygeal vertebrae via the caudal approach in each gelding; the catheter tip was threaded approximately 10 cm cranial into the midsacral region. Each horse received 4 epidural treatments: 2% lidocaine (0.2 mg/kg) alone and 3 doses of neostigmine (0.5, 1, or 2 μg/kg) coadministered with that same dose of lidocaine. Horses were restrained in stocks in a standing position. Heart rate, blood pressure, respiratory rate, rectal temperature, intestinal motility, analgesia, behavior, and ataxia were determined before treatment (time 0; baseline); at 5, 10, 15, 30, 45, 60, 75, and 90 minutes; and every 30 minutes thereafter until the cessation of analgesia. Results: All doses of neostigmine coadministered with lidocaine improved and extended the duration of analgesia in the perineal region of the geldings. Total duration of analgesia was not a dose-dependent effect (120, 150, and 150 minutes for 0.5, 1, and 2 μg/kg, respectively). All treatments induced mild or moderate ataxia. Cardiovascular changes were within acceptable limits. Conclusions and Clinical Relevance: Administration of neostigmine (1 μg/kg) combined with lidocaine (0.2 mg/kg) in the caudal epidural space induced analgesia for 2.5 hours with a low prevalence of adverse effects in standing conscious geldings. Epidural doses of neostigmine greater than these should be avoided because they may cause undesirable effects in geldings.

Objective: To assess joint kinematics in dogs with osteoarthritis of the hip joints during walking up an incline or down a decline and over low obstacles and to compare findings with data for nonlame dogs. Animals: 10 dogs with osteoarthritis of the hip joints (mean ± SD age, 6.95 ± 3.17 years; mean body weight, 34.33 ± 13.58 kg) and 8 nonlame dogs (3.4 ± 2.0 years; 23.6 ± 4.6 kg). Procedures: Reflective markers located on the limbs and high-speed cameras were used to record joint kinematics during walking up an incline or down a decline and over low obstacles. Maximal flexion, extension, and range of motion of the hip joints were calculated. Results: Osteoarthritis of the hip joints reduced extension of both hip joints and flexion of the contralateral hind limb, compared with flexion of the lame hind limb, during walking down a decline. Walking up an incline resulted in decreased extension of the stifle joint in both hind limbs of osteoarthritic dogs; extension was significantly decreased for the lame hind limb. During walking over low obstacles, maximal flexion of the stifle joint was increased significantly for the contralateral hind limb. Maximal flexion was increased in both tarsal joints. Conclusions and Clinical Relevance: Osteoarthritis of the hip joints led to complex changes in the gait of dogs, which involved more joints than the affected hip joint alone. Each exercise had specific effects on joint kinematics that must be considered when planning a rehabilitation program.

Objective: To determine the influence of intensified training and subsequent reduced training on glucose metabolism rate and peripheral insulin sensitivity in horses and identify potential markers indicative of early overtraining. Animals: 12 Standardbred geldings. Procedures: Horses underwent 4 phases of treadmill-based training. In phase 1, horses were habituated to the treadmill. In phase 2, endurance training was alternated with high-intensity exercise training. In phase 3, horses were divided into control and intensified training groups. In the intensified training group, training intensity, duration, and frequency were further increased via a protocol to induce overtraining; in the control group, these factors remained unaltered. In phase 4, training intensity was reduced. Standardized exercise tests were performed after each phase and hyperinsulinemic euglycemic clamp (HEC) tests were performed after phases 2, 3, and 4. Results: 10 of 12 horses completed the study. Dissociation between mean glucose metabolism rate and mean glucose metabolism rate-to-plasma insulin concentration ratio (M:I) was evident in the intensified training group during steady state of HEC testing after phases 3 and 4. After phase 4, mean glucose metabolism rate was significantly decreased (from 31.1 ± 6.8 μmol/kg/min to 18.1 ± 3.4 μmol/kg/min), as was M:I (from 1.05 ± 0.31 to 0.62 ± 0.17) during steady state in the intensified training group, compared with phase 3 values for the same horses. Conclusions and Clinical Relevance: Dissociation between the glucose metabolism rate and M:I in horses that underwent intensified training may reflect non-insulin–dependent increases in glucose metabolism.

Objective: To characterize acute inflammatory and hemostatic surgical stress responses following castration in cats and to evaluate whether the addition of local anesthesia to the anesthetic protocol attenuates these responses. Animals: 39 male cats. Procedures: Cats undergoing castration were randomly assigned to 2 groups: both groups underwent surgery with general anesthesia, and 1 group additionally received a local anesthetic (lidocaine [2.0 mg/kg in total, divided intratesticularly and SC]) prior to incision. Blood samples were collected after anesthetic induction (baseline) and 1, 5, and 24 hours later. Thromboelastography and coagulation variables (activated partial thromboplastin time [aPTT] and prothrombin time [PT]) were analyzed; fibrinolysis was assessed with plasma D-dimer concentrations. The acute-phase response was evaluated via measurement of plasma fibrinogen and serum amyloid A (last time point, 28 hours) concentrations. Hematologic variables were analyzed at baseline and 1, 5, and 24 hours later. Results: Evidence of hemostatic and inflammatory activation after surgery was detected in both groups. Maximum amplitude and G (global clot strength) were significantly increased at 24 hours, and significant, but not clinically relevant, decreases were detected in aPTT at 5 and 24 hours and in PT at 24 hours, compared with baseline values. Serum amyloid A concentrations were significantly higher at 24 and 28 hours than at baseline, and plasma fibrinogen concentration was significantly increased at 24 hours; WBC and RBC counts and Hct were significantly increased at multiple time points. No differences between groups were detected for any variables. Conclusions and Clinical Relevance: Castration appeared to induce hypercoagulability and an acute-phase inflammatory response in cats. Local anesthesia with lidocaine did not attenuate this response.

Objective: To describe the anatomic features of dentition and surrounding structures of the head in rabbits assessed by use of a newly developed micro-computed tomography (CT) device. Sample: Cadavers of 7 clinically normal adult Dendermonde White domestic rabbits raised for human consumption. Procedures: The rabbits were slaughtered in a slaughterhouse, flayed, and decapitated; the rabbit heads were frozen for micro-CT examination. Transverse images were obtained from the nares to the occipital condyles with a custom-designed micro-CT scanner built at the Ghent University Centre for X-ray Tomography. Scan settings were chosen to highlight bony structures on the basis of the designers' experience. The micro-CT images were reviewed, and all recognizable anatomic features were labeled. Afterward, micro-CT images were used to create 3-D reconstructions by use of a custom-developed reconstruction package and 3-D rendering with dedicated software. Results: Microstructures of the bones and teeth were clearly visible on micro-CT images. Conversely, soft tissue contrast was relatively poor on these images. Conclusions and Clinical Relevance: Micro-CT appeared to be a promising technique for appropriate diagnosis of dental disease in rabbits. Further research is needed to determine the clinical applications of micro-CT imaging.

Objective: To characterize adiponectin protein complexes in lean and obese horses. Animals: 26 lean horses and 18 obese horses. Procedures: Body condition score (BCS) and serum insulin activity were measured for each horse. Denaturing and native western blot analyses were used to evaluate adiponectin complexes in serum. A human ELISA kit was validated and used to quantify high–molecular weight (HMW) complexes. Correlations between variables were made, and HMW values were compared between groups. Results: Adiponectin was present as a multimer consisting of HMW (> 720-kDa), low-molecular weight (180-kDa), and trimeric (90-kDa) complexes in serum. All complexes were qualitatively reduced in obese horses versus lean horses, but the percentage of complexes < 250 kDa was higher in obese versus lean horses. High–molecular weight adiponectin concentration measured via ELISA was negatively correlated with serum insulin activity and BCS and was lower in obese horses (mean ± SD, 3.6 ± 3.9 μg/mL), compared with lean horses (8.0 ± 4.6 μg/mL). Conclusions and Clinical Relevance: HMW adiponectin is measurable via ELISA, and concentration is negatively correlated with BCS and serum insulin activity in horses. A greater understanding of the role of adiponectin in equine metabolism will provide insight into the pathophysiology of metabolic disease conditions.

Objective: To evaluate the accuracy of artificial neural networks (ANNs) for use in predicting subjective diagnostic scores of lameness with variables determined from ground reaction force (GRF) data. Animals: 21 adult mixed-breed dogs. Procedures: The left cranial cruciate ligament of each dog was transected to induce osteoarthritis of the stifle joint as part of another study. Lameness scores were assigned and GRF data were collected 2 times before and 5 times after ligament transection. Inputs and the output for each ANN were GRF variables and a lameness score, respectively. The ANNs were developed by use of data from 14 dogs and evaluated by use of data for the remaining 7 dogs (ie, dogs not used in model development). Results: ANN models developed with 2 preferred input variables had an overall accuracy ranging from 96% to 99% for 2 data configurations (data configuration 1 contained patterns or observations for 7 dogs, whereas data configuration 2 contained patterns or observations for 7 other dogs). When additional variables were added to the models, the highest overall accuracy ranged from 97% to 100%. Conclusions and Clinical Relevance: ANNs provided a method for processing GRF data of dogs to accurately predict subjective diagnostic scores of lameness. Processing of GRF data via ANNs could result in a more precise evaluation of surgical and pharmacological intervention by detecting subtle lameness that could have been missed by visual analysis of GRF curves.