Objective—To determine renal arterial resistive index (RI) and pulsatility index (PI) and clinical signs of overhydration induced by IV administration of saline (0.9% NaCl) solution and to assess RI and PI as variables for monitoring of dogs to detect overhydration.
Animals—10 clinically normal Beagles.
Procedures—Each dog received saline solution at a maintenance rate (2.5 mL/kg/h) and a rate 3 times that of the maintenance rate (overhydration rate; 7. 5 mL/kg/h). Values of RI and PI were determined with pulsed-wave Doppler ultrasonographic examination of renal interlobar or arcuate arteries before saline solution administration, every hour during 5 hours of administration, and 1 hour after administration was stopped.
Results—No significant changes in RI or PI were detected during administration of saline solution at the maintenance rate. However, RI (starting 1 hour after the beginning of fluid administration [mean ± SD value, 0.589 ± 0.012]) and PI (starting 2 hours after the beginning of fluid administration [value, 0.867 ± 0.052]) were significantly lower during administration at the overhydration rate than they were during administration at the maintenance rate. Clinical signs of overhydration were observed in all dogs starting 4 hours after the beginning of fluid administration at the overhydration rate.
Conclusions and Clinical Relevance—Results indicated overhydration of dogs caused significant decreases in RI and PI prior to detection of clinical signs of overhydration. Ultrasonographic determination of renal arterial RI and PI seemed to be a noninvasive and sensitive method for evaluation of overhydration in dogs.
To investigate the clinical feasibility of attenuation imaging of the hepatic parenchyma in healthy dogs, identify technical factors that influence measured attenuation coefficients, and determine intraobserver repeatability of measurements.
10 healthy Beagles.
Attenuation coefficients were calculated for various measurement sites (left vs central division of the liver), scanning planes (transverse vs sagittal plane), scanning depths (10 to 20 mm vs 20 to 30 mm), scanning approaches (intercostal vs subcostal approach), and breathing conditions (free breathing vs breath holding at end expiration). Intraoperator intraday and interday reliability was assessed by computing intraclass correlation coefficients.
Attenuation coefficients were not influenced significantly by scanning plane (P = .120 to 1.000), measurement site (P = .292 to .848), or breathing condition (P = .166). However, coefficients were significantly (P < .01) less with deeper scanning depths and significantly (P < .05) more for the subcostal approach than the intercostal approach. The intraday and interday intraclass correlation coefficients showed good repeatability (0.799 and 0.771, respectively), regardless of the scanning plane and measurement site. Scanning the central division of the liver with the right intercostal approach at a depth of 10 to 20 mm from the liver capsule yielded good reliability.
Attenuation imaging was a feasible technique for evaluating the hepatic parenchyma in healthy dogs with good repeatability. Measured attenuation coefficients were not affected by the scanning plane, measurement site, or breathing condition.
To fluoroscopically evaluate the effects of head posture and sedation on the laryngopharyngeal anatomic structures in dogs.
6 clinically normal Beagles (mean age, 6.2 years; mean weight, 10.4 kg).
Each dog was sedated and placed in right lateral recumbency, and fluoroscopic examinations were performed with flexed, neutral, and extended head postures (FHP, NHP, and EHP, respectively). During 3 respiratory cycles, the angle between the basisphenoid bone and nasopharyngeal dorsal border (ABN), thickness of the soft palate, diameter of the nasopharyngeal lumen (DNL), overlapping length between the epiglottis and soft palate, and distance between the epiglottis and tympanic bulla (DET) were measured and percentage difference in the DNL (PDNLD) during a respiratory cycle was calculated.
For the FHP, NHP, and EHP, median ABN was 91.50° (interquartile range [IQR], 86.75° to 95.00°), 125.00° (IQR, 124.50° to 125.50°), and 160.00° (IQR, 160.00° to 163.50°), respectively, with no significant differences between ABN and posture angle. For the FHP, median DNL and DET significantly decreased, compared with values for the NHP, and median thickness of the soft palette significantly increased. For the EHP, the minimal DNL and DET significantly increased, and the median overlapping length between the epiglottis and soft palate significantly decreased, compared with values for the NHP. The PDNLD significantly increased and decreased with FHP and EHP, respectively, compared with the PDNLD with NHP. Sedation did not affect upper airway structure changes.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that head posture significantly affected the laryngopharyngeal structures in dogs. Fluoroscopic examination of the upper respiratory tract of a dog should be performed with an NHP to minimize posture-induced changes in measurements.
To compare shear-wave velocities (SWVs) with shear-wave elastography of various peripheral lymph nodes (LNs).
11 healthy Beagles.
For each dog, bilateral mandibular, medial retropharyngeal, superficial cervical, axillary, superficial inguinal, and popliteal LNs were evaluated with shear-wave elastography in sagittal and transverse scanning planes. Depth of each lymph node was recorded, and intra- and interobserver reliability was determined.
SWVs for all LNs were significantly higher in the sagittal scanning plane, compared with those in the transverse scanning plane. The SWV of the most superficial LN, the mandibular LN, was significantly higher, compared with that for the other LNs, except for the medial retropharyngeal LN. The SWV of the deepest LN, the medial retropharyngeal LN, was as high as that for the mandibular LN. Intra- and interobserver reliability was excellent.
CONCLUSIONS AND CLINICAL RELEVANCE
SWVs for normal peripheral LNs of Beagles may serve as a reference to compare with those for other breeds and diseased LNs. Scanning plane, LN depth, and interfering tissues between the LN and the transducer may affect SWV. Shear-wave elastography may not be operator dependent.