ULTRASONOGRAPHIC APPEARANCE OF CANINE PARVOVIRAL ENTERITIS IN PUPPIES NERISSA STANDER,WENCKE M. WAGNER,AMELIA GODDARD,ROBERT M. KIRBERGER The ultrasonographic appearance of the gastrointestinal tract of puppies suffering from parvoviral enteritis was characterized. Forty puppies between 6 and 24 weeks of age with confirmed canine parvoviral enteritis were examined ultrasonographically within 24 h of admission. Sonographic findings included fluid-filled small in- testines in 92.5% of subjects, and stomach and colon in 80% and 62.5% of subjects, respectively. Generalized atony was present in 30 subjects and weak peristaltic contractions indicative of functional ileus observed in the remaining 10 subjects. The duodenal and jejunal mucosal layer thicknesses were significantly reduced when compared with normal puppies with mean duodenal mucosal layer measuring 1.7 mm and jejunal mucosal layer 1.0 mm. Additionally, a mucosal layer with diffuse hyperechoic speckles was seen in the duodenum (15% of subjects) and the jejunum (50% of subjects). The luminal surface of the duodenal mucosa was irregular in 22.5% of subjects and the jejunal mucosa in 42.5% of subjects. In all of these subjects, changes were ac- companied by generalized indistinct wall layering. Small intestinal corrugations were seen within the duodenum in 35% of subjects and within the jejunum in 7.5%. A mild amount of anechoic free peritoneal fluid was observed in 26 subjects and was considered within normal limits and a moderate amount of anechoic free peritoneal fluid was observed in six subjects. The jejunal lymph node size was within normal limits. None of the above changes are pathognomonic for canine parvoviral enteritis but finding them in combination is highly suggestive. Veterinary Radiology & Ultrasound, Vol. 51, No. 1, 2010, pp 69–74. Key words: enteritis, gastrointestinal, mucosa, parvovirus, puppy, ultrasonography. Introduction C ANINE PARVOVIRAL ENTERITIS is a significant disease of high prevalence in South Africa, predominantly in puppies. Without treatment, mortality may reach 91%. 1 Canine parvovirus targets rapidly proliferating tissues. In puppies, commonly affected tissues are lymphoid tissues, intestinal epithelium, bone marrow and, less commonly, heart. 2 Histopathologically, destruction of intestinal crypt epithelial cells with loss of villi and dilation of the remain- ing crypts with necrotic debris or complete loss of crypts is seen. In extreme infections, collapse of the intestinal mu- cosa may be found. 3,4 The stomach often contains large quantities of thick mucus with normal underlying mucosa. 4 The colon is rarely affected. The jejunal lymph nodes may be enlarged, congested, or reduced in size. 3 Little information is available on the ultrasonographic appearance of acute inflammatory intestinal lesions in dogs. 5,6 Enteritis results in mild to moderate intestinal wall thickening without loss of layering throughout most of the length of the intestines. 7 In some severe inflammatory con- ditions, intestinal wall layers can be significantly affected or lost completely. 7,8 Altered motility is often present. De- creased motility is often associated with fluid and mucus sonographic bowel patterns and has been noted in func- tional and mechanical ileus. 9 Corrugations of the intestinal wall may be seen in enteritis due to irritability and spasm and has been observed in dogs with serologically proven parvoviral infection. 10 The ultrasonographic appearance of parvoviral enteritis has been described in a 2-month-old puppy. 5 Generalized fluid distended, atonic small intestine with presumed normal (3 mm) intestinal wall thickness was seen. 5 Mild to moderate lymph node enlargement can be seen in inflammatory or infectious bowel disease. 7 The abnor- mal lymph nodes usually enlarge and become hypoechoic or anechoic, but often retain a smooth margin and a homo- genous echo pattern. In humans, rotavirus is the most im- portant cause of pediatric dehydrating gastroenteritis in the world. 11 In that disease, increased ileal wall thickness and increased number and size of jejunal lymph nodes were noted in the acute phase of infection. 11 Our aim was to describe the gastrointestinal ultrasono- graphic changes associated with canine parvovirus infec- tion. It was hypothesized that acute canine parvovirus infection causes characteristic ultrasonographic gastroin- testinal changes such as generalized atonic, fluid distended intestines, thinning or echogenicity changes within the Address correspondence and reprint requests to Nerissa Stander, at the above address. E-mail: nerissa.stander@up.ac.za Received May 29, 2009; accepted for publication August 16, 2009. doi: 10.1111/j.1740-8261.2009.01625.x From the Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderste- poort 0110, Republic of South Africa. 69