Effects of Midazolam and Midazolam-Butorphanol on Gastrointestinal Transit Time and Motility in Cockatiels (Nymphicus hollandicus).

Positive contrast gastrointestinal (GI) studies are performed frequently in avian medicine to identify GI obstruction, luminal distension, and intracoelomic mass effects. However, repeated manual restraint and radiographic positioning may result in a stress-response and associated morbidity in birds, which can be attenuated by administration of sedative drugs. In mammals, many sedative drugs have been shown to affect GI transit times and motility. In this randomized, blinded, controlled prospective study, the effects of midazolam (M; 6 mg/kg IM) and midazolam-butorphanol (MB; 3 mg/kg each IM) on GI transit times were evaluated in 12 healthy cockatiels (Nymphicus hollandicus). Iohexol (20 mL/kg) was administered by crop gavage 15 minutes after induction of sedation, and fluoroscopic images were obtained at different time points. Both sedation protocols significantly affected GI transit times and motility, and the MB protocol had more pronounced effects. Overall median (range) GI transit times were 60 (30-120), 90 (30-120), and 120 (120-180) minutes for the control, M, and MB groups, respectively. Ventricular contractions were markedly reduced with both sedation protocols, while esophageal boluses were reduced only in the MB group. Visualization of the GI tract after iohexol administration was graded highest in the control group and poorest in the MB group. Our results show that commonly used sedative drugs have significant effects on GI transit time and motility in birds. Therefore, GI transit times obtained in sedated birds should not be compared to available reference transit times obtained from unsedated animals.

Contrast fluoroscopic evaluation of gastrointestinal transit times with and without the use of falconry hoods in red-tailed hawks (Buteo jamaicensis).

OBJECTIVE To evaluate gastrointestinal transit times in red-tailed hawks (Buteo jamaicensis) by use of contrast fluoroscopic imaging and investigate the effect of falconry hooding in these hawks on gastrointestinal transit time. DESIGN Prospective, randomized, blinded, complete crossover study. ANIMALS 9 healthy red-tailed hawks. PROCEDURES Hawks were gavage-fed a 30% weight-by-volume barium suspension (25 mL/kg [11.3 mL/lb]) into the crop. Fluoroscopic images were obtained at multiple time points after barium administration. Time to filling and emptying of various gastrointestinal tract organs and overall transit time were measured. The effect of hooding (hooded vs nonhooded) on these variables was assessed in a randomized complete crossover design. RESULTS In nonhooded birds, overall gastrointestinal transit time ranged from 30 to 180 minutes (mean ± SD, 100 ± 52 min). Time to complete crop emptying ranged from 30 to 180 minutes (83 ± 49 min). Contrast medium was present in the ventriculus in all birds within 5 minutes of administration and in the small intestines within 5 to 15 minutes (median, 5 min). Hooding of red-tailed hawks resulted in a significant delay of complete crop emptying (no hood, 83 ± 49 minutes; hood, 133 ± 48 minutes), but no significant effects of hooding were found on other measured variables. CONCLUSIONS AND CLINICAL RELEVANCE These results indicated that overall gastrointestinal transit times are faster in red-tailed hawks than has been reported for psittacines and that the use of a falconry hood in red-tailed hawks may result in delayed crop emptying. Hooding did not exert significant effects on overall gastrointestinal transit time in this raptorial species.

Determination of Gastrointestinal Transit Times in Barred Owls ( Strix varia ) by Contrast Fluoroscopy.

Contrast imaging studies are routinely performed in avian patients when an underlying abnormality of the gastrointestinal (GI) tract is suspected. Fluoroscopy offers several advantages over traditional radiography and can be performed in conscious animals with minimal stress and restraint. Although birds of prey are commonly encountered as patients, little is known about GI transit times and contrast imaging studies in these species, especially owls. Owls are commonly encountered in zoological, educational, and wildlife settings. In this study, 12 adult barred owls ( Strix varia ) were gavage fed a 30% weight-by-volume barium suspension (25 mL/kg body weight). Fluoroscopic exposures were recorded at 5, 15, 30, 60, 120, 180, 240, and 300 minutes after administration. Overall GI transit time and transit times of various GI organs were recorded. Median (interquartile range [IQR]) overall GI transit time was 60 minutes (IQR: 19-60 minutes) and ranged from 5-120 minutes. Ventricular and small intestinal contrast filling was rapid. Ventricular emptying was complete by a median of 60 minutes (IQR: 30-120 minutes; range: 30-240 minutes), whereas small intestinal emptying was not complete in 9/12 birds by 300 minutes. Median small intestinal contraction rate was 15 per minute (IQR: 13-16 minutes; range: 10-19 minutes). Median overall GI transit time in barred owls is more rapid than mean transit times reported for psittacine birds and red-tailed hawks ( Buteo jamaicensis ). Fluoroscopy is a safe, suitable method for investigating GI motility and transit in this species.

COMPARISON OF FLUOROSCOPY AND COMPUTED TOMOGRAPHY FOR TRACHEAL LUMEN DIAMETER MEASUREMENT AND DETERMINATION OF INTRALUMINAL STENT SIZE IN HEALTHY DOGS.

Tracheal collapse is a progressive airway disease that can ultimately result in complete airway obstruction. Intraluminal tracheal stents are a minimally invasive and viable treatment for tracheal collapse once the disease becomes refractory to medical management. Intraluminal stent size is chosen based on the maximum measured tracheal diameter during maximum inflation. The purpose of this prospective, cross-sectional study was to compare tracheal lumen diameter measurements and subsequent selected stent size using both fluoroscopy and CT and to evaluate inter- and intraobserver variability of the measurements. Seventeen healthy Beagles were anesthetized and imaged with fluoroscopy and CT with positive pressure ventilation to 20 cm H2 O. Fluoroscopic and CT maximum tracheal diameters were measured by three readers. Three individual measurements were made at eight predetermined tracheal sites for dorsoventral (height) and laterolateral (width) dimensions. Tracheal diameters and stent sizes (based on the maximum tracheal diameter + 10%) were analyzed using a linear mixed model. CT tracheal lumen diameters were larger compared to fluoroscopy at all locations (P-value < 0.0001). When comparing modalities, fluoroscopic and CT stent sizes were statistically different. Greater overall variation in tracheal diameter measurement (height or width) existed for fluoroscopy compared to CT, both within and among observers. The greater tracheal diameter measured with CT and lower measurement variability has clinical significance, as this may be the imaging modality of choice for appropriate stent selection to minimize complications in veterinary patients.

Effect of 6-8 weeks of oral ursodeoxycholic acid administration on serum concentrations of fasting and postprandial bile acids and biochemical analytes in healthy dogs.

BACKGROUND: Ursodeoxycholic acid (UDCA) is commonly used for the treatment of hepatobiliary disease. UDCA is a bile acid that can be detected in the bile acid assay. Its effect on biochemical analytes is unknown. OBJECTIVES: The aim of this study was to determine the effect of 6-8 weeks of UDCA administration on fasting and postprandial concentrations of serum bile acids (SBA), cholesterol, triglycerides, bilirubin, and liver enzyme activities in healthy dogs. METHODS: Twenty healthy dogs received UDCA for 6-8 weeks. CBC, biochemistry profile, urinalysis, fasting and postprandial SBA, and hepatobiliary ultrasound examination were performed prior to starting UDCA (timepoint 0) and after 6-8 weeks of therapy, while animals were still receiving UDCA (timepoint 1). Timepoint 0 and timepoint 1 values were compared with a paired t-test. SBA were remeasured 72 hours after UDCA discontinuation. RESULTS: Only mean fasting SBA at timepoint 1 increased significantly (P = .03) from timepoint 0 (2.26 µmol/L at time 0 and 3.81 µmol/L at time 1) but were not elevated above the normal reference interval (0-9 µmol/L). Two dogs had timepoint 1 fasting SBA above the reference interval (10 and 11.7 µmol/L). One dog had timepoint 1 postprandial SBA above the reference interval at 20.1 µmol/L (reference interval 0-17 µmol/L). Repeat SBA 72 hours after UDCA discontinuation were normal. CONCLUSIONS: Long-term administration of UDCA to healthy dogs may increase fasting SBA above pretreatment values (typically within the reference interval). Long-term administration of UDCA to healthy dogs does not alter liver enzyme activities, and bilirubin, cholesterol, or triglyceride concentrations.

Suspected primary hematomyelia in 3 dogs.

Primary hematomyelia refers to hemorrhage occurring within the spinal cord without an identifiable etiology. Clinical signs, magnetic resonance imaging characteristics, and histopathological findings are described. Diagnosis was made through histological analysis and rule-outs for underlying factors. Following removal of the hematoma, neurologic deficits improved, although some residual deficits persisted.

Hématomyélie primaire suspectée chez 3 chiens. L'hématomyélie primaire fait référence à l'hémorragie qui se produit dans la moelle épinière sans une étiologie identifiable. Les signes cliniques, les caractéristiques de l'imagerie par résonance magnétique et les résultats de l'histopathologie sont décrits. Le diagnostic a été posé à l'aide d'une analyse histologique et de l'élimination des facteurs sous-jacents. Après l'enlèvement de l'hématome, le déficit neurologique s'est amélioré, même si des déficits résiduels ont persisté.(Traduit par Isabelle Vallières).

Interobserver variability of radiographic pulmonary nodule diameter measurements in dogs and cats.

The purpose of this study was to determine the interobserver variability of radiographic pulmonary nodule diameter measurements among readers with varying levels of experience. Because interobserver variability may lead to inaccurate estimations of nodule growth on repeat radiographic assessment, an incorrect presumption of malignant etiology or misclassification of tumor response to treatment may result. The maximum diameters of 47 pulmonary nodules from 22 dogs and 7 cats were measured. Measurements were performed using one digital thoracic radiographic projection by eight clinicians. The eight clinicians included two interns, two residents, two board-certified veterinary specialists, and two board-certified veterinary radiologists. A mixed-effect analysis of variance model was used to evaluate the contribution of reader, experience level, patient, nodule, and nodule size to the overall variability in mean pulmonary nodule diameter. The interobserver variability in diameter measurement for any given nodule was 16%, and experience level and nodule size classification did not contribute to measurement variability. Linear measurements of the diameter of a pulmonary nodule can vary significantly among a group of clinicians; however, depending on the criteria used to evaluate nodule growth or tumor response, the 16% interobserver variability reported here is likely not clinically significant.