USE OF CONTRAST HARMONIC ULTRASOUND FOR THE DIAGNOSIS OF CONGENITAL PORTOSYSTEMIC SHUNTS IN THREE DOGS

Contrast harmonic ultrasound was used to determine macrovascular and perfusion patterns in three dogs with congenital extrahepatic solitary portosystemic shunts (PSS). With coded harmonic angiographic ultrasound, the size and tortuosity of the hepatic arteries were subjectively increased. Single pulse intermittent low-amplitude harmonic perfusion imaging provided contrast enhancement time-intensity curves from regions of interest in the liver. Mean (+/- standard deviation) peak perfusion times of dogs with PSS were significantly shorter (p = 0.01; 7.0 +/- 2.0 s) than reported in normal dogs (22.8 +/- 6.8 s). The contrast inflow slope for the dogs with PSS (14.6 +/- 3.7 pixel intensity units [PIU] was significantly (p = 0.05) larger than reported for normal dogs (3.6 +/- 1.4 PIU/s). These results indicate that combined coded harmonic angiographic and contrast harmonic perfusion sonography can be used to detect increased hepatic arterial blood flow as an indicator of PSS in dogs.     

ULTRASOUND EVALUATION OF SMALL BOWEL THICKNESS COMPARED TO WEIGHT IN NORMAL DOGS

The use of ultrasound to measure small bowel thickness is an important part of any ultrasound examination of the abdomen. Increased thickness of the intestinal wall is a hallmark for the detection of diseases ranging from inflammatory bowel disease to neoplasia. Our subjective impression has been that dogs with no clinical signs of gastrointestinal disease often have sonographic measurements greater than published norms. The purpose of this study was to prospectively reevaluate these norms. The clinical history on all dogs receiving an abdominal ultrasound examination was evaluated for signs of gastrointestinal disease. Those without clinical signs were entered into this study. The documentation of body weight, breed, jejunal thickness, and duodenal thickness was made in 231 dogs. Dogs were placed into five groups based on their weight. Sixty-nine breeds were represented with weight ranging from 2.1 to 64 kg. A statistically significant (P < or = 0.05) correlation between body weight and both jejunal and duodenal thickness was observed. We also found that the maximum thickness in both jejunum and duodenum in healthy dogs was larger than previously reported. These data indicate norms for the jejunum of < or = 4.1 mm for dogs up to 20 kg, < or = 4.4 mm for dogs between 20 and 39.9 kg, and < or = 4.7 mm for dogs over 40 kg. The data indicate norms for the duodenum < or = 5.1 mm for dogs up to 20 kg, < or = 5.3 kg for dogs between 20 and 29.9 kg, and < or = 6.0 mm for dogs over 30 kg.     

Thoracic Radiographic Features of Silicosis in 19 Horses

Clinical records and thoracic radiographs of 19 horses with a confirmed pathologic diagnosis of silicosis were reviewed. These horses had histories of varying degrees of chronic weight loss, exercise intolerance, and respiratory distress. At the time of presentation, two horses were asymptomatic. Ten horses were geldings and nine were female. The mean age of the 19 horses was 10.7 +/- 5.5 years. Fourteen horses were identified as being from the Monterey-Carmel Peninsula of midcoastal California. An abnormal, structured interstitial pulmonary pattern was identified on thoracic radiographs in each horse. The interstitial pulmonary changes were classified as miliary (13 horses), reticulonodular (4), or linear interstitial (2), and were best visualized dorsally and caudodorsally. In addition to the abnormal interstitial pulmonary pattern, areas of pulmonary consolidation were evident caudodorsally in seven horses. Other thoracic radiographic features included: hilar lymphadenopathy (4 horses), pleural effusion/thickening (4), cranial mediastinal lymphadenopathy (2), hyperinflation (1), and a discrete pulmonary mass (1). Necropsy findings in eight horses and results of lung biopsies in an additional five horses showed a diffuse, multifocal, granulomatous pneumonia with areas of pulmonary fibrosis. Cellular infiltrates included predominantly macrophages with intracellular and/or extracellular crystalline material, occasional lymphocytes, and giant cells. Similar cellular changes were also identified, during necropsy, in the hilar and tracheobronchial lymph nodes in each of the eight horses, although gross enlargement of the lymph nodes was present in only six horses. The radiographic and pathologic findings of these 19 horses are consistent with chronic or the accelerated forms of silicosis that are recognized in humans.