This study investigated oxidative stress biomarkers at 3 different oxygen concentrations in dogs under general anesthesia to determine whether high-concentration oxygen increases oxidative stress. Six healthy beagles were randomly assigned to receive 3 anesthesia protocols (inhalation of 40%, 60%, and 100% oxygen) during 3 hours of general anesthesia with sevoflurane, with at least one week in between each protocol. For each experiment, blood samples were collected at 0, 3, 6, and 24 hours after inhalation of oxygen. Derivatives of reactive oxygen metabolites, biochemical antioxidant potential, superoxide dismutase, and 8-hydroxydeoxyguanosine in the blood did not significantly differ among the 3 groups at any time point. This study is the first comparing high concentrations of oxygen with low concentrations of oxygen for anesthesia in dogs. According to our findings, 100% oxygen may not alter the oxidative stress level in dogs during general anesthesia with sevoflurane for 3 hours.

OBJECTIVE To evaluate the thermal antinociceptive effects of hydromorphone hydrochloride after IM administration to orange-winged Amazon parrots (Amazona amazonica). ANIMALS 8 healthy adult parrots (4 males and 4 females). PROCEDURES In a randomized crossover study, each bird received hydromorphone (0.1, 1, and 2 mg/kg) and saline (0.9% NaCl) solution (1 mL/kg; control) IM, with a 7-day interval between treatments. Each bird was assigned an agitation-sedation score, and the thermal foot withdrawal threshold (TFWT) was measured at predetermined times before and after treatment administration. Adverse effects were also monitored. The TFWT, agitation-sedation score, and proportion of birds that developed adverse effects were compared among treatments over time. RESULTS Compared with the mean TFWT for the control treatment, the mean TFWT was significantly increased at 0.5, 1.5, and 3 hours and 1.5, 3, and 6 hours after administration of the 1- and 2-mg/kg hydromorphone doses, respectively. Significant agitation was observed at 0.5, 1.5, and 3 hours after administration of the 1 - and 2-mg/kg hydromorphone doses. Other adverse effects observed after administration of the 1- and 2-mg/kg doses included miosis, ataxia, and nausea-like behavior (opening the beak and moving the tongue back and forth). CONCLUSIONS AND CLINICAL RELEVANCE Although the 1- and 2-mg/kg hydromorphone doses appeared to have antinociceptive effects, they also caused agitation, signs of nausea, and ataxia. Further research is necessary to evaluate administration of lower doses of hydromorphone and other types of stimulation to better elucidate the analgesic and adverse effects of the drug in psittacine species.

There is evidence that perfusing the heart with a heart and lung machine is less injurious than cross-clamping the aorta and administering cardioplegia during cardiac surgery. Although mitral valve replacement has been carried out without aortic cross-clamping and cardioplegia, it has been stated that cross-clamping is necessary in order to maintain visualization and a motionless surgical field for mitral valve repair. The purpose of this study was to determine the surgical feasibility of mitral valve repair without cross-clamping the aorta and using cardioplegia. Our hypothesis was that a completely bloodless and motion-free field would not be necessary to carry out mitral valve repair with annuloplasty and synthetic chordae tendineae sutures. Papillary muscles, chordae tendineae, annulus, and mitral valve leaflets were all readily visualized. Chordae tendineae sutures were used and annuloplasty was conducted without visual obstruction or motion interference. Our results show that mitral valve repair is feasible without cross-clamping the aorta and using cardioplegia.

OBJECTIVE To establish a method for evaluation of the efficacy of a classical swine fever virus (CSFV) subunit vaccine in rabbits as determined via humoral immune responses to the virus. ANIMALS 40 specific pathogen–free rabbits. PROCEDURES Rabbits were randomly assigned to 4 groups (10 rabbits/group) for SC injection of 0.05, 0.1, and 0.2 mL of a CSFV subunit E2 vaccine (representing 1.15, 2.3, or 4.6 μg of E2 protein/dose, respectively) or saline (0.9% NaCl) solution. Blood samples were collected 21 days after vaccination for measurement of the antibody response against CSFV via ELISA and virus neutralization methods. On the same day, the CSFV Chinese (C) strain was injected into an ear vein. Vaccine efficacy was determined by monitoring of rabbits for pyrexia for 4 days and measurement of viral copies in spleen lysates at the end of the study. Reproducibility of the antibody response was tested with 2 other batches of the vaccine at the minimum immunization dose identified for the initially tested batch. RESULTS The E2 protein dose of the initially tested vaccine was positively correlated with the antibody response and protection rate in rabbits. The identified minimum immunization dose per rabbit was 0.1 mL, representing an E2 protein content of approximately 2.3 μg, and reproducibility of the antibody response to vaccination with the 2 other batches at this dose was good. CONCLUSIONS AND CLINICAL RELEVANCE A method was established in rabbits for evaluation of the efficacy of a CSFV subunit vaccine that could help in the optimization of later large-scale vaccine production and quality control processes as well as in the clinical application of the vaccine.

OBJECTIVE To determine the pharmacokinetics of amantadine after oral administration of single and multiple doses to orange-winged Amazon parrots (Amazona amazonica). ANIMALS 12 adult orange-winged Amazon parrots (6 males and 6 females). PROCEDURES A single dose of amantadine was orally administered to 6 birds at 5 mg/kg (n = 2), 10 mg/kg (2), and 20 mg/kg (2) in a preliminary trial. On the basis of the results, a single dose of amantadine (10 mg/kg, PO) was administered to 6 other birds. Two months later, multiple doses of amantadine (5 mg/kg, PO, q 24 h for 7 days) were administered to 8 birds. Heart rate, respiratory rate, behavior, and urofeces were monitored. Plasma concentrations of amantadine were measured via tandem liquid chromatography–mass spectrometry. Pharmacokinetic parameter estimates were determined via noncompartmental analysis. RESULTS Mean ± SD maximum plasma concentration, time to maximum plasma concentration, half-life, and area under the concentration-versus-time curve from the last dose to infinity were 1,174 ± 186 ng/mL, 3.8 ± 1.8 hours, 23.2 ± 2.9 hours, and 38.6 ± 7.4 μg·h/mL, respectively, after a single dose and 1,185 ± 270 ng/mL, 3.0 ± 2.4 hours, 21.5 ± 5.3 hours, and 26.3 ± 5.7 μg·h/mL, respectively, at steady state after multiple doses. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Once-daily oral administration of amantadine at 5 mg/kg to orange-winged Amazon parrots maintained plasma concentrations above those considered to be therapeutic in dogs. Further studies evaluating safety and efficacy of amantadine in orange-winged Amazon parrots are warranted.

OBJECTIVE To compare a ventral and a left lateral endoscopic approach to coelioscopy in bearded dragons (Pogona vitticeps). ANIMALS 18 adult bearded dragons. PROCEDURES In a randomized crossover design involving 2 surgical approaches, anesthetized bearded dragons first underwent coelioscopy with a ventral approach (left lateral of midline next to the umbilicus; animal positioned in dorsal recumbency) or left lateral approach (intercostal; animal positioned in right lateral recumbency) and then with the alternate approach. A 2.7-mm × 18-cm, 30° oblique telescope with a 4.8-mm operating sheath and CO2 insufflation at 2 to 5 mm Hg were used. Ease of entry into the coelom and ease of visual examination of visceral structures were scored. RESULTS Both approaches were straightforward, with the left lateral approach requiring significantly more time than the ventral approach. Scores for ease of visual examination for the heart, lungs, liver, stomach, intestines, pancreas, gallbladder, left kidney, gonads, and fat body were good to excellent. Visual examination of the spleen and adrenal glands was difficult in most animals via either approach. The left kidney, testis, and vas deferens were easier to see with the left lateral approach, whereas the pancreas in females and gallbladder in both sexes were easier to see with the ventral approach. All bearded dragons recovered without complications from the procedures, except for one with nephritis, renal gout, and hepatic necrosis. CONCLUSIONS AND CLINICAL RELEVANCE Both coelioscopy approaches could be safely and effectively used in bearded dragons. Choice of approach should be based on the coelomic structures requiring evaluation.

OBJECTIVE To determine whether a customized unilateral intervertebral anchored fusion device combined with (vs without) an intervertebral spacer would increase the stability of the L1-L2 motion segment following complete intervertebral diskectomy in canine cadaveric specimens. SAMPLE Vertebral columns from T13 through L3 harvested from 16 skeletally mature Beagles without thoracolumbar disease. PROCEDURES Complete diskectomy of the L1-2 disk was performed in each specimen. Unilateral stabilization of the L1-L2 motion segment was performed with the first of 2 implants: a unilateral intervertebral anchored fusion device that consisted of a locking compression plate with or without an intervertebral spacer. The resulting construct was biomechanically tested; then, the first implant was removed, and the second implant was applied to the contralateral side and tested. Range of motion in flexion and extension, lateral bending, and torsion was compared among intact specimens (prior to diskectomy) and constructs. RESULTS Compared with intact specimens, constructs stabilized with either implant were as stable in flexion and extension, significantly more stable in lateral bending, and significantly less stable in axial rotation. Constructs stabilized with the fusion device plus intervertebral spacer were significantly stiffer in lateral bending than those stabilized with the fusion device alone. No significant differences in flexion and extension and rotation were noted between implants. CONCLUSIONS AND CLINICAL RELEVANCE Findings did not support the use of this customized unilateral intervertebral anchored fusion device with an intervertebral spacer to improve unilateral stabilization of the L1-L2 motion segment after complete L1-2 diskectomy in dogs.

OBJECTIVE To determine whether blood taurine concentrations in dogs with exocrine pancreatic insufficiency (EPI) were lower than the reference interval (200 to 350 nmol/mL) or the cutoff used to indicate taurine deficiency (< 150 nmol/mL). ANIMALS 18 dogs with clinical or presumptive subclinical EPI with residual blood samples available for taurine concentration analysis. PROCEDURES Dogs were classified as having clinical EPI if they had a serum trypsin-like immunoreactivity concentration of < 2.0 μg/L and presumptive subclinical EPI if they had a concentration of 2.0 to 5.0 μg/L. Archived, frozen blood samples stored in EDTA were submitted for measurement of taurine concentration with an automated high-performance liquid chromatography amino acid analyzer. Medical record data were examined for associations with blood taurine concentration. RESULTS None of the 18 dogs had a blood taurine concentration < 150 nmol/mL. Two dogs had a concentration < 200 nmol/mL. No clinical signs, physical examination findings, or serum biochemical abnormalities were associated with blood taurine concentration. Eleven of the 17 dogs for which diet histories were available were not receiving a diet that met recommendations of the World Small Animal Veterinary Association Global Nutrition Committee. CONCLUSIONS AND CLINICAL RELEVANCE A low blood taurine concentration was noted in a small subset of dogs with EPI. Additional research is needed to determine whether EPI was the primary cause of this low concentration. Findings suggested the importance of obtaining complete diet histories and ensuring dietary requirements are sufficiently met in dogs with EPI.

Various types of human and nonhuman adenoviral (AdV) vectors are being used as gene delivery vectors in preclinical and clinical investigations. The objective of this study was to determine the ratio between the 2 best assays that would effectively address the variability in the titration of various AdV vectors in different cell lines and help obtain consistent results in preclinical and clinical studies using different AdV vectors. Here, we compared plaque-forming units, tissue culture infectious dose 50, focus-forming units (FFU), virus particle (VP) count, and genome copy number (GCN) of purified preparations of human AdV type C5, bovine AdV type 3, and porcine AdV type 3 to determine a correlation between infectious and noninfectious virus particles. Our results suggest that a VP:FFU or a VP:GCN ratio could accurately reflect the quality of an AdV preparation and could serve as an indicator to control batch-to-batch variability.

The aim of this study was to assess the genetic variability of Mycoplasma hyopneumoniae within various swine production flows. Four M. hyopneumoniae positive production flows, composed of 4 production stages, were selected for this study. Laryngeal and/or bronchial swabs were collected from each production stage within a flow, for a period of 4 months up to 3 years. A multiple-locus variable-number tandem repeat analysis was performed to assess the genetic variation of M. hyopneumoniae within and across production flows through the identification of variable-number tandem repeat (VNTR) types. A maximum of 6 M. hyopneumoniae VNTR types were identified in a single flow, in which VNTR types appeared to be flow specific. An identical VNTR type was detected across several production stages for up to 3 years. In this study, minimal M. hyopneumoniae genetic variation was evidenced within and across production flows.