The value of ultrasonography was evaluated in 85 dogs and 17 cats presented with a clinically suspected portosystemic shunt (PSS). A PSS was confirmed in 50 dogs and nine cats (single congenital extrahepatic in 42, single congenital intrahepatic in 11, and multiple acquired in six). Six dogs and one cat had hepatic microvascular dysplasia, and 29 dogs and seven cats had a normal portal system. Ultrasonography was 92% sensitive, 98% specific, and had positive and negative predictive values of 98% and 89%, respectively, in identifying PSS, with an overall accuracy of 95%. When a PSS was identified with ultrasonography, extrahepatic, intrahepatic, and multiple acquired PSS could be correctly differentiated in 53/54 patients (98%). The combination of a small liver, large kidneys, and uroliths had positive and negative predictive values of 100% and 51% for the presence of a congenital PSS in dogs. The portal vein/aorta (PV/Ao) and portal vein/caudal vena cava (PV/ CVC) ratios were smaller in animals with extrahepatic PSSs compared with animals with microvascular dysplasia, intrahepatic PSSs and those without portal venous anomalies (P<0.001). All dogs and cats with a PV/Ao ratio of < or = 0.65 had an extrahepatic PSS or idiopathic noncirrhotic portal hypertension. Dogs and cats with PV/Ao and PV/CVC ratios of > or = 0.8 and > or = 0.75, respectively, did not have an extrahepatic PSS. Reduced or reversed portal flow was seen in four of four patients with multiple acquired PSSs secondary to portal hypertension. The presence of turbulence in the caudal vena cava of dogs had positive and negative predictive values of 91% and 84%, respectively, for the presence of any PSS terminating into that vein.

Renal size is an important parameter in the assessment of renal disease in dogs. However, because of the great variability in body conformation, absolute renal measurements cannot solely be used when evaluating kidneys with ultrasonography. The use of a ratio comparing renal length and aortic luminal diameter (K/Ao) was investigated. After confirming the reproducibility of these measurements, K/Ao ratios were obtained in 92 dogs without clinical evidence of renal disease. Left and right K/Ao ratios were statistically similar. Based on 95% confidence intervals, renal size should be considered reduced if the K/Ao ratio is < 5.5 and increased when > 9.1.

The differentiation of benign vs. neoplastic lymph nodes impacts patient management. Specific sonographic features are typically considered when assessing lymph nodes in dogs. However, the usefulness of these criteria in distinguishing benign vs. malignant lymph nodes remains largely unknown, especially for deep lymph nodes. Our aim was to compare sonographic features in benign and neoplastic deep lymph nodes with the hope of identifying predictive criteria. Thirty-one deep lymph nodes (16 mesenteric, 10 medial iliac, three hepatic, one sternal, and one cranial mediastinal) in 31 dogs were examined prospectively with B-mode and Color flow Doppler. Lymph nodes were aspirated using ultrasound-guidance and final diagnosis were established based on cytologic and/or histopathologic interpretation. Prevalence of each sonographic feature and combinations of two features was calculated for each group and compared using a χ(2) -test or Student's t-test for unequal variances. Ten lymph nodes were benign (hyperplastic and/or inflammatory) and 21 were neoplastic. All were hypoechoic, except for one neoplastic lymph node. Maximal short-axis diameter (P=0.0006) and long-axis diameter (P=0.01), and SA/LA ratio (P=0.008) were increased significantly for neoplastic (2.8, 5.5 cm, and 0.50, respectively) vs. benign (1.2, 3.8 cm, and 0.34, respectively) lymph nodes. The prevalence of other features was similar between groups. Doppler evaluation was possible in 77% of lymph nodes, but there was no significant difference between groups. When any two ultrasound features were combined, the only difference between benign and neoplastic lymph nodes was for the combination of contour regularity and appearance of the perinodal fat (P=0.03).

Clinical data, thoracic radiographs, ultrasonographic exams, and histopathologic reports in 13 dogs and two cats with confirmed lung lobe torsion were reviewed. Age of dogs ranged from 4 months to 11.5 years, (mean of 6.4 years) and several breeds of large and small dogs were represented. Right middle lobe torsion was predominant in large dogs (five of eight large breed dogs) and left cranial lobe torsion was more commonly seen in small dogs (three of five small-breed dogs). Two domestic short-hair cats, 10 and 14 years of age, had right cranial and right middle lobe torsion, respectively. Underlying thoracic disease was found in only five of 15 patients. On thoracic radiographs, increased lobar opacity and pleural effusion were found in all patients (100%). Small dispersed air bubbles were found within the affected lobe of 13 patients (87%). This pattern, which was the result of vesicular emphysema, was variably extensive, and became more evident on follow-up radiographs in five of six dogs. The lobar bronchi could be seen in only eight of 15 patients (54%), and appeared irregular, focally narrowed or blunted in six of the eight patients, and displaced in five of the eight. Other common radiographic findings included mediastinal shift (nine), curved and dorsally displaced trachea (seven), and axial rotation of the carina (seven). Ultrasonography was used in seven patients and considered generally useful, although variable signs were observed.

Renal pelvic dilatation is often recognized sonographically in dogs and cats, but ranges of measurements expected with different urologic conditions remain unknown. Ultrasound images of 81 dogs and 66 cats with renal pelvic dilatation were reviewed, and six groups were formed based on medical records: (I) clinically normal renal function, and (II) clinically normal renal function with diuresis; (III) pyelonephritis; (IV) noninfectious renal insufficiency; (V) outflow obstruction; (VI) miscellaneous nonobstructive anomalies. Medians for maximal pelvic width (range) for group I was 2.0 mm (1.0-3.8) in 11 dogs, and 1.6 mm (0.8-3.2) in 10 cats; for group II, 2.5 mm (1.3-3.6) in 15 dogs, and 2.3 mm (1.1-3.4) in 16 cats; for group III, 3.6 mm (1.9-12.0) in nine dogs, and 4.0 mm (1.7-12.4) in seven cats; for group IV, 3.1 mm (0.5-10.8) in 33 dogs, and 2.8 mm (1.2-7.3) in 13 cats; for group V, 15.1 mm (5.1-76.2) in six dogs, and 6.8 mm (1.2-39.1) in 17 cats; and for group VI, 3.8 mm (1.2-7.6) in seven dogs, and 3.0 mm (1.3-7.5) in three cats. Pelvic width in group I was lower than in groups III-V (P ¼ 0.0001), but did not significantly differ from group II. Pelvic width !13 mm always indicated obstruction. While the proportion of bilateral pelvic dilatation was not different among groups, the difference in pelvic width (maximal-minimal) was greater in group V vs. groups I, II, and IV (P ¼ 0.0009). These results confirm that renal pelvic dilatation can be detected sonographically in dogs and cats with clinically normal renal function, and that it increases with renal insufficiency, pyelonephritis, or outflow obstruction. Nevertheless, renal pelvic width varies substantially within groups and should be interpreted with caution. r