This study established a disease model and protocol for bacterial challenge with Escherichia coli serogroup O2 strain EC317 in Japanese quail. Five groups of 10 birds each were injected subcutaneously in the breast with 200 μL of a brain–heart infusion (BHI) culture containing 1 × 10(8), 1 × 10(7), 1 × 10(6), 1 × 10(5), or 1 × 10(4) colony-forming units/mL of the test organism, which had been isolated from a turkey with cellulitis and septicemia. Birds in a 6th group were controls that received sterile BHI alone. Localized lesions of cellulitis developed in all of the birds that received E. coli. The morbidity and mortality rates were highest (100%) in the birds receiving the highest dose of E. coli and decreased linearly with decreasing dose (P < 0.05). Severity of disease, including lesions of pericarditis and perihepatitis, was also directly proportional to the dose of E. coli. These findings indicate that this disease challenge protocol can be used to study disease resistance and immunologic consequences of contaminant exposure or other stressors in birds.

This is one of few published population-based studies describing breed specific rates of canine primary bone tumors. Incidence rates related to dog breeds could help clarify the impact of etiological factors such as birth weight, growth rate, and adult body weight/height on development of these tumors. The study population consisted of dogs within 4 large/giant breeds; Irish wolfhound (IW), Leonberger (LB), Newfoundland (NF), and Labrador retriever (LR), born between January 1st 1989 and December 31st 1998. Questionnaires distributed to owners of randomly selected dogs - fulfilling the criteria of breed, year of birth, and registration in the Norwegian Kennel Club - constituted the basis for this retrospective, population-based survey. Of the 3748 questionnaires received by owners, 1915 were completed, giving a response rate of 51%. Forty-three dogs had been diagnosed with primary bone tumors, based upon clinical examination and x-rays. The breeds IW and LB, with 126 and 72 cases per 10 000 dog years at risk (DYAR), respectively, had significantly higher incidence rates of primary bone tumors than NF and LR (P < 0.0001). Incidence rates for the latter were 11 and 2 cases per 10 000 DYAR, respectively. Pursuing a search for risk factors other than body size/weight is supported by the significantly different risks of developing primary bone tumors between similarly statured dogs, like NF and LB, observed in this study. Defining these breed-specific incidence rates enables subsequent case control studies, ultimately aiming to identify specific etiological factors for developing primary bone tumors.

Objective--To establish a computed tomography (CT)-angiography protocol and measure the diameters of major arteries in parrots. Animals--13 Hispaniolan Amazon parrots (Amazona ventralis). Procedures--16-slice CT scanning was used to measure the apparent diameter of the ascending aorta, abdominal aorta, pulmonary arteries, and brachiocephalic trunk. Before scanning, all birds underwent ECG and echocardiographic assessment and were considered free of detectable cardiovascular diseases. Each bird was anesthetized, and a precontrast helical CT scan was performed. Peak aortic enhancement was established with a test bolus technique via dynamic axial CT scan over a predetermined single slice. An additional bolus of contrast medium was then injected, and a helical CT-angiography scan was performed immediately afterward. Arterial diameter measurements were obtained by 2 observers via various windows before and after injection, and intra- and interobserver agreement was assessed. Results--Reference limits were determined for arterial diameter measurements before and after contrast medium administration in pulmonary, mediastinal, and manual angiography windows. Ratios of vertebral body diameter to keel length were also calculated. Intraobserver agreement was high (concordance correlation coefficients ≥ 0.95); interobserver agreement was medium to high (intraclass correlation coefficients ≥ 0.65). Conclusions and Clinical Relevance--CT-angiography was safe and is of potential diagnostic value in parrots. We recommend performing the angiography immediately after IV injection of 3 mL of iohexol/kg. Arterial diameter measurements at the described locations were reliable.

Objective--To investigate the roles of transforming growth factor-β (TGF-β) isoforms and matrix metalloproteinases (MMPs) in development of chronic mitral valvular disease (CMVD) in dogs. Sample Population--12 mitral valve leaflets collected from cadavers of 5 clinically normal dogs and from 7 dogs with CMVD. Procedures--Expression of TGF-β isoforms 1, 2, and 3; MMPs 1, 2, 3, and 9; TGF-β receptor II (TβR-II); and α smooth muscle actin (αSMA) in mitral valves of dogs with CMVD was compared with that in mitral valves from clinically normal dogs. Additionally, responses of valvular interstitial cells (VICs) to TGF-β3, MMP-3, and angiotensin-converting enzyme inhibitor (ACEI) as a suppressor of TGF-β3 were examined in vitro. Results--Expression of TGF-β3, TβR-II, αSMA, and MMP-3 was only detected in mitral valves of dogs with CMVD. Concentrations of αSMA and proteoglycans in cultured VICs were significantly increased following incubation with TGF-β3; treatment with MMP-3 resulted in increased amounts of active and total TGF-β3, and total TGF-β3 in VICs was significantly decreased by incubation with ACEI. Conclusions and Clinical Relevance--Findings suggested that increased TGF-β3 and MMP-3 contribute to the pathogenesis of valvular degeneration associated with CMVD. In addition, it is possible that the use of ACEI could effectively block pathological alterations in VICs associated with CMVD in vitro. Impact on Human Medicine--CMVD is associated with primary mitral valve prolapse and Marfan syndrome in humans. Results of the study reported here will help to elucidate the molecular mechanisms of CMVD in dogs and humans.

Objective—To describe daily, hourly, and animal-to-animal effects on lying behavior in steers. Animals—25 crossbred beef steers. Procedures—Wireless accelerometers were used to record behavioral data for cattle housed in a drylot cattle research facility during two 20-day periods (winter 2007 [n = 10 steers] and spring 2008 [15]). Behavioral data were categorized into lying, standing, and walking behaviors for each time point recorded. Logistic regression models were used to determine potential associations between the percentage of time spent lying and several factors, including time (hour) of day, day of trial, and steer. Results—Lying behavior was significantly associated with hour of day, and a distinct circadian rhythm was identified. Steers spent > 55% of the time between 8:00 pm and 4:00 am lying and were most active (<30% lying behavior) during feeding periods (6:00 am to 7:00 am and 4:00 pm to 5:00 pm). Model-adjusted mean percentage of time spent lying was significantly associated with study day and was between 45% and 55% on most (27/40 [67.5%]) days. Lying behavior varied significantly among steers, and mean ± SD percentage of time spent lying ranged from 28.9 ± 6.1 % to 66.1 ± 6.6%. Conclusions and Clinical Relevance—Cattle had distinct circadian rhythm patterns for lying behavior, and percentage of time spent lying varied by day and among steers. Researchers need to account for factors that affect lying patterns of cattle (ie, time of day, day of trial, and individual animal) when performing research with behavioral outcomes.

Objective—To compare cardiovascular effects of sevoflurane alone and sevoflurane plus an IV infusion of lidocaine in horses. Animals—8 adult horses. Procedures—Each horse was anesthetized twice via IV administration of xylazine, diazepam, and ketamine. During 1 anesthetic episode, anesthesia was maintained by administration of sevoflurane in oxygen at 1.0 and 1.5 times the minimum alveolar concentration (MAC). During the other episode, anesthesia was maintained at the same MAC multiples via a reduced concentration of sevoflurane plus an IV infusion of lidocaine. Heart rate, arterial blood pressures, blood gas analyses, and cardiac output were measured during mechanical (controlled) ventilation at both 1.0 and 1.5 MAC for each anesthetic protocol and during spontaneous ventilation at 1 of the 2 MAC multiples. Results—Cardiorespiratory variables did not differ significantly between anesthetic protocols. Blood pressures were highest at 1.0 MAC during spontaneous ventilation and lowest at 1.5 MAC during controlled ventilation for either anesthetic protocol. Cardiac output was significantly higher during 1.0 MAC than during 1.5 MAC for sevoflurane plus lidocaine but was not affected by anesthetic protocol or mode of ventilation. Clinically important hypotension was detected at 1.5 MAC for both anesthetic protocols. Conclusions and Clinical Relevance—Lidocaine infusion did not alter cardiorespiratory variables during anesthesia in horses, provided anesthetic depth was maintained constant. The IV administration of lidocaine to anesthetized nonstimulated horses should be used for reasons other than to improve cardiovascular performance. Severe hypotension can be expected in nonstimulated horses at 1.5 MAC sevoflurane, regardless of whether lidocaine is administered.

Objective--To characterize the localization, visible extent (ie, measurement of selected dimensions), and appearance of the liver, caudal vena cava, portal vein, and gallbladder during ultrasonography in healthy goats. Animals--27 female Saanen goats. Procedures--A 5.0-MHz linear transducer was used to ultrasonographically examine the localization, visible extent of various dimensions, and appearance of the liver, caudal vena cava, portal vein, and gallbladder from the right side of each goat. Results--Images of the liver were obtained in all goats. The dorsal margin of the liver extended in a cranioventral to caudodorsal direction parallel to the caudal margin of the lungs. The greatest visible extent of the liver was evident at the seventh and eighth intercostal spaces (mean value, 15.9 cm), and width was evident at the 10th intercostal space (mean value, 5.2 cm). The caudal vena cava had a triangular shape on cross section; the maximum width in cross section, circumference, and surface area ranged from 1.2 to 1.8 cm, 4.8 to 5.2 cm, and 0.8 to 1.1 cm2, respectively. The portal vein was round on cross section (diameter, 0.8 to 1.7 cm) with stellate ramifications into the liver parenchyma. The gallbladder was pear-shaped and variable in size; it extended beyond the ventral margin of the liver to a variable degree depending on the amount of bile. Conclusions and Clinical Relevance--Results provided information regarding the ultrasonographic appearance of the liver, caudal vena cava, portal vein, and gallbladder in healthy goats; these data may be useful during examination of goats with suspected liver disease.

Objective: To determine accuracy of the use of triaxial accelerometry for measuring daily activity as a predictor of maintenance energy requirement (MER) in healthy adult Labrador Retrievers. Animals—10 healthy adult Labrador Retrievers. Procedures: Dogs wore an accelerometer for two 2-week periods, with data on daily activity successfully collected for 24 to 26 days. These data, along with body weight, were used as independent variables in a multiple linear regression model to predict the dependent variable of daily MER. The predictive accuracy of the model was compared with that of a model that excluded activity. Dietary energy intake at a stated amount of body weight stability was used as an equivalent measure of MER in these analyses. Results: The multiple linear regression model that included body weight and daily activity as independent variables could be used to predict observed MER with a mean absolute error of 63.5 kcal and an SE of estimation of 94.3 kcal. Removing activity from the model reduced the predictive accuracy to a mean absolute error of 129.8 kcal and an SE of estimation of 165.4 kcal. Conclusions and Clinical Relevance: Use of triaxial accelerometers to provide an independent variable of daily activity yielded a marked improvement in predictive accuracy of the regression model, compared with that for a model that used only body weight. Improved accuracy in estimations of MER could be made for each dog if an accelerometer was used to record its daily activity.

The objective of this study was to estimate the presence of the important foodborne pathogen Campylobacter jejuni in organically raised chickens in the province of Quebec. The recovered isolates were further characterized for their antimicrobial resistance profile, autoagglutination property and chemotaxis. Antimicrobial resistance was evaluated using agar dilution for: tetracycline, erythromycin, chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid, clindamycin, ampicillin, azithromycin, bacitracin, and ceftiofur. Autoagglutination was measured by monitoring optical density changes in a bacterial suspension after 3 h of incubation at room temperature. Chemotaxis was evaluated after a contact time of 3 h between isolates and mucin, using a quantitative protocol. A total of 10 lots of chickens was sampled in August and September 2009; half of them were positive for the presence of C. jejuni. Antimicrobial resistance was found only for tetracycline (44%), erythromycin (6%), azithromycin (6%) and clindamycin (2%). Variation was observed in the minimum inhibitory concentrations (MICs) for ceftiofur and bacitracin, for which C. jejuni possess intrinsic resistance. Autoagglutination and chemotaxis varied among isolates and lot-level differences in these were observed. Autoagglutination and chemotaxis levels appeared as independent isolate properties. Further monitoring and characterization of isolates originating from organic chickens is of interest since this type of production might represent another source of exposure of consumers to a variety of the foodborne pathogen C. jejuni.

This study was focused on the genotyping and quantification of Porcine circovirus type 2 (PCV2) in thirty PCV2-positive pigs with different clinical symptoms (PCV2-infected without wasting, PCV2-infected with wasting, PCV2-infected with wasting and lymphoid depletion). The quantity of PCV2 DNA in diverse tissues was significantly differed among these groups. (One-way ANOVA test, p less than 0.001) Interestingly, PCV2-DNA load in tissues of PCV2-infected pigs without wasting and PCV2-infected pigs with wasting and lymphoid depletion were not significantly differed (p = 0.38), while they were all significantly higher when compared with PCV2-infected pigs with wasting-only. PCV2 DNA quantity in tissues was significantly higher in PCV2a and 2b co-infected pigs compared to the PCV2b only-infected pigs (Wilcoxon test, p = 0.039). The PCV2a and 2b co-infected pigs had increased wasting and lymphoid depletion rate but it was not statistically significant. Therefore, this cross-sectional study suggested that PCV2 DNA load in tissues was diverse by clinical and histological findings. Furthermore, co-infection of PCV2a and 2b affected to the PCV2 DNA load in tissues with increased rate of wasting and lymphoid depletion.