OBJECTIVE To determine the plasma total antioxidant capacity, erythrocyte superoxide dismutase activity, whole blood glutathione peroxidase activity, and plasma coenzyme Q10 (CoQ10) concentration in dogs with various stages of cardiovascular diseases and in healthy dogs; assess the influence of cardiac treatment on the levels of antioxidant variables, plasma CoQ10 concentration, and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, and determine any correlation between the disease severity (NT-proBNP concentration) and antioxidant variables or CoQ10 concentration. ANIMALS 43 dogs with various types and stages of cardiovascular diseases (congenital and acquired) and 29 healthy dogs. PROCEDURES Blood samples were collected from all dogs for spectrophotometric assessment of antioxidant variables. Plasma CoQ10 concentration was determined with a high-performance liquid chromatography–atmospheric pressure chemical ionization–tandem mass spectrometry method. Serum NT-proBNP concentration was measured with an ELISA. RESULTS Values for antioxidant variables did not differ among groups of dogs with cardiovascular diseases, regardless of disease stage or treatment. Plasma CoQ10 concentration was significantly increased in treated dogs with congestive heart failure (CHF), compared with untreated patients. However, plasma CoQ10 concentration did not differ among heart failure classes. A significant, negative correlation between serum NT-proBNP and plasma CoQ10 concentrations was identified in treated CHF-affected dogs, suggesting that low plasma CoQ10 concentration may be associated with increased severity of CHF. CONCLUSIONS AND CLINICAL RELEVANCE The antioxidant variables evaluated were not altered in dogs with CHF, regardless of cardiac disease stage or treatment. Further investigation into the possible effects of CoQ10 supplementation in dogs with advanced stages of CHF is warranted.

OBJECTIVE To evaluate and compare morphological characteristics of the dens in atlantoaxial instability (AAI)-predisposed toy-breed dogs (TBDs) with and without AAI and non–AAI-predisposed healthy Beagles. ANIMALS 80 AAI-affected and 40 nonaffected TBDs and 40 Beagles. PROCEDURES Each dog underwent CT examination of the cervical vertebral column. On median 3-D multiplanar reconstruction images, the dens angle (DA) was measured as were the lengths of the dens and the body of the axis; the dens-to-axis length ratio (ratio of the dens length to the axis body length [DALR]) was calculated. Data were compared among dog groups. RESULTS The DALR in nonaffected TBDs and Beagles did not differ significantly. The mean DALR for AAI-affected TBDs was significantly lower than that for nonaffected TBDs. The mean DA of AAI-affected TBDs was significantly greater than that of Beagles and nonaffected TBDs. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that a low DALR might be associated with a high probability of dens abnormalities in TBDs. Additionally, dens length in AAI-affected TBDs appeared to be smaller than that in non–AAI-affected TBDs, given the low DALR in AAI-affected TBDs. Further investigations to determine reference ranges of the DA and DALR and the potential usefulness of those variables as diagnostic markers for AAI in TBDs are warranted.

Ultrasonography is not often used in feline dermatology. The purpose of this study was to assess the usefulness and applicability of ultrasonography for skin evaluation in 21 clinically healthy cats. Ultrasonographic examination was conducted in 4 cutaneous regions (frontal, dorsal neck, sacral, and abdominal) using an 18-MHz linear-sequential-array transducer. Findings were assessed using histomorphometric analysis of skin samples set as reference standards. Morphologic evaluation, thickness measurements, measurement variability, and comparison between regions and genders were carried out. The ultrasonographic pattern of feline skin was characterized by 3 distinct layers of different echogenicity and echostructure. Skin was thickest at the dorsal neck region and thinnest at the abdominal region. Skin at the frontal region and dorsal neck region was thicker in males. Variability was < 10% in all regions. No apparent correspondence was found between ultrasonographic and histometric measurements of skin thickness. Collectively, these findings suggest that ultrasonography is a simple, noninvasive, and reproducible technique that allows cutaneous layers to be identified and accurately measures skin thickness in cats.

OBJECTIVE To evaluate mechanical properties of pigeon (Columba livia) cadaver intact humeri versus ostectomized humeri stabilized with a locking or nonlocking plate. SAMPLE 30 humeri from pigeon cadavers. PROCEDURES Specimens were allocated into 3 groups and tested in bending and torsion. Results for intact pigeon humeri were compared with results for ostectomized humeri repaired with a titanium 1.6-mm screw locking plate or a stainless steel 1.5-mm dynamic compression plate; the ostectomized humeri mimicked a fracture in a thin cortical bone. Locking plates were secured with locking screws (2 bicortical and 4 monocortical), and nonlocking plates were secured with bicortical nonlocking screws. Constructs were cyclically tested nondestructively in 4-point bending and then tested to failure in bending. A second set of constructs were cyclically tested non-destructively and then to failure in torsion. Stiffness, strength, and strain energy of each construct were compared. RESULTS Intact specimens were stiffer and stronger than the repair groups for all testing methods, except for nonlocking constructs, which were significantly stiffer than intact specimens under cyclic bending. Intact bones had significantly higher strain energies than locking plates in both bending and torsion. Locking and nonlocking plates were of equal strength and strain energy, but not stiffness, in bending and were of equal strength, stiffness, and strain energy in torsion. CONCLUSIONS AND CLINICAL RELEVANCE Results for this study suggested that increased torsional strength may be needed before bone plate repair can be considered as the sole fixation method for avian species.

OBJECTIVE To acquire MRI diffusion data (apparent diffusion coefficient [ADC] and fractional anisotropy [FA] values, including separate measures for gray and white matter) at 3.0 T for multiple locations of the brain of neurologically normal dogs. ANIMALS: 13 neurologically normal dogs recruited from a group of patients undergoing tibial plateau leveling osteotomy. PROCEDURES: MRI duration ranged from 20 to 30 minutes, including obtaining preliminary images to exclude pathological changes (T2-weighted fluid-attenuated inversion recovery transverse and dorsal images) and diffusion-weighted images., RESULTS: Globally, there were significant differences between mean values for gray and white matter in the cerebral lobes and cerebellum for ADC (range of means for gray matter, 0.8349 × 10(−3) s/mm2 to 0.9273 × 10(−3) s/mm2; range of means for white matter, 0.6897 × 10(−3) s/mm2 to 0.7332 × 10(−3) s/mm2) and FA (range of means for gray matter, 0.1978 to 0.2364; range of means for white matter, 0.5136 to 0.6144). These values also differed among cerebral lobes. In most areas, a positive correlation was detected between ADC values and patient age but not between FA values and patient age. CONCLUSIONS AND CLINICAL RELEVANCE: Cerebral interlobar and cerebellar diffusion values differed significantly, especially in the gray matter. Information about diffusion values in neurologically normal dogs may be used to diagnose and monitor abnormalities and was the first step in determining the clinical use of diffusion imaging. This information provided an important starting point for the clinical application of diffusion imaging of the canine brain.

MK-467 is a peripherally acting α2-adrenoceptor antagonist due to its low lipid solubility and poor penetration of the blood-brain barrier (BBB). The aim of this study was to assess whether MK-467 could be a substrate of an active efflux transport mechanism. Using Madin-Darby Canine Kidney cells (MDCKII) and MDCKII cells transfected with the human multidrug resistance gene 1, drug transport was assessed in apical-basolateral and basolateral-apical directions. MK-467 was studied at 2 concentrations: 200 and 1000 ng/mL. Samples for analysis were taken at 15, 30, 45, 60, and 90 min after drug application. Drug concentrations were measured using liquid chromatography and mass spectrometry. MK-467 showed no apparent permeability in the apical-basolateral direction, transport in the basolateral-apical direction occurred in both cell lines. Efflux ratios were not calculated. However, MK-467 appeared to undergo active cellular transport. The identity of the transporter requires further investigation.

Genus Iotatorquevirus consists of 2 species, Torque teno sus virus 1a and Torque teno sus virus 1b, which are ubiquitous in swine populations, and are widely reported in association with porcine circovirus associated disease (PCVAD). To evaluate the relationship with PCVAD, 100 formalin-fixed paraffin-embedded tissue samples were used to detect both Iotatorquevirus species by nested PCR and sequencing. Sixty-eight PCVAD cases were selected as well as 32 porcine circovirus type 2 (PCV2) non-affected cases. Overall, 33 of the 100 cases were positive for Torque teno sus virus 1a and 8 of 100 were positive for Torque teno sus virus 1b. Only 24 of 68 (35%) PCVAD cases were positive for Torque teno sus virus 1a; 39% (9/23) of post-weaning multisystemic wasting syndrome, and 33% (15/45) of PCV2-associated reproductive failure cases. Among PCV2 non-affected cases, 28% were positive for Torque teno sus virus 1a and 6% were positive for Torque teno sus virus 1b. Torque teno sus virus 1b was not detected in PCV2-associated reproductive failure cases. Regardless of the PCV2-status, a lower frequency of both Iotatorquevirus species was found than depicted in other reports and there was no statistical relationship with PCVAD (χ 2 < 0.01). Given the worldwide genomic variability of Iotatorquevirus species, it is feasible that species prevalent in Mexico share a lower nucleotide sequence identity, leading to different pathogenic potential.

This study evaluated the circulating levels of serum symmetric dimethylarginine (SDMA) in 12 dogs with different severities of heartworm disease (HWD) and assessed the biochemical renal markers (blood urea nitrogen, creatinine). Dogs were classified into 2 groups based on the severity of clinical signs. Group A - asymptomatic to mild clinical signs, group B - moderate to severe clinical signs. The serum SDMA levels were higher in dogs in group B. Although the serum SDMA levels in dogs in group A were also higher than those of the control dogs, the difference was not statistically significant. There was a good correlation between renal markers and severity of clinical signs. This study demonstrated that the glomerular filtration rate was significantly decreased in dogs in group A; therefore, earlier detection of renal impairment is required for successful management of dogs with HWD.

OBJECTIVE To evaluate pharmaceutical characteristics (strength or concentration, accuracy, and precision), physical properties, and bacterial contamination of fluconazole compounded products. SAMPLE Fluconazole compounded products (30- and 240-mg capsules; 30- and 100-mg/mL oral suspensions) from 4 US veterinary compounding pharmacies. PROCEDURES Fluconazole compounded products were ordered 3 times from each of 4 pharmacies at 7- or 10-day intervals. Generic fluconazole products (50- and 200-mg tablets; 10- and 40-mg/mL oral suspensions) served as references. Compounded products were evaluated at the time of receipt; suspensions also were evaluated 3 months later and at beyond-use dates. Evaluations included assessments of strength (concentration), accuracy, precision, physical properties, and bacterial contamination. Acceptable accuracy was defined as within ± 10% of the labeled strength (concentration) and acceptable precision as within ± 10%. Fluconazole was quantified by use of high-performance liquid chromatography. RESULTS Physical characteristics of compounded products differed among pharmacies. Aerobic bacterial cultures yielded negative results. Capsules (30 and 240 mg) had acceptable accuracy (median, 96.3%; range, 87.3% to 135.2%) and precision (mean ± SD, 7.4 ± 6.0%). Suspensions (30 and 100 mg/mL) had poor accuracy (median, 73.8%; range, 53.9% to 95.2%) and precision (mean ± SD, 15.0 ± 6.9%). Accuracy and precision were significantly better for capsules than for suspensions. CONCLUSIONS AND CLINICAL RELEVANCE Fluconazole compounded products, particularly suspensions, differed in pharmaceutical and physical qualities. Studies to evaluate the impact of inconsistent quality on bioavailability or clinical efficacy of compounded fluconazole products are indicated, and each study should include data on the quality of the compounded product evaluated.

OBJECTIVE To measure concentrations of trazodone and its major metabolite in plasma and urine after administration to healthy horses and concurrently assess selected physiologic and behavioral effects of the drug. ANIMALS 11 Thoroughbred horses enrolled in a fitness training program. PROCEDURES In a pilot investigation, 4 horses received trazodone IV (n = 2) or orally (2) to select a dose for the full study; 1 horse received a vehicle control treatment IV. For the full study, trazodone was initially administered IV (1.5 mg/kg) to 6 horses and subsequently given orally (4 mg/kg), with a 5-week washout period between treatments. Blood and urine samples were collected prior to drug administration and at multiple time points up to 48 hours afterward. Samples were analyzed for trazodone and metabolite concentrations, and pharmacokinetic parameters were determined; plasma drug concentrations following IV administration best fit a 3-compartment model. Behavioral and physiologic effects were assessed. RESULTS After IV administration, total clearance of trazodone was 6.85 ± 2.80 mL/min/kg, volume of distribution at steady state was 1.06 ± 0.07 L/kg, and elimination half-life was 8.58 ± 1.88 hours. Terminal phase half-life was 7.11 ± 1.70 hours after oral administration. Horses had signs of aggression and excitation, tremors, and ataxia at the highest IV dose (2 mg/kg) in the pilot investigation. After IV drug administration in the full study (1.5 mg/kg), horses were ataxic and had tremors; sedation was evident after oral administration. CONCLUSIONS AND CLINICAL RELEVANCE Administration of trazodone to horses elicited a wide range of effects. Additional study is warranted before clinical use of trazodone in horses can be recommended.