Ultrasonographic findings in dogs with hyperammonemia: 90 cases (2000-2002).
OBJECTIVE
To determine ultrasonographic abnormalities in dogs with hyperammonemia.


METHODS
Retrospective study.


METHODS
90 client-owned dogs with hyperammonemia.


METHODS
Ultrasonography of the abdominal vessels and organs was performed in a systematic way. Dogs in which the ultrasonographic diagnosis was a congenital portosystemic shunt were included only if they underwent laparotomy or necropsy. Dogs in which the abdominal vasculature appeared normal and dogs in which the ultrasonographic diagnosis was acquired portosystemic shunts and portal hypertension were included only if liver biopsy specimens were submitted for histologic examination.


RESULTS
Ultrasonography excluded portosystemic shunting in 11 dogs. Acquired portosystemic shunts were found in 17 dogs, of which 3 had arterioportal fistulae and 14 had other hepatic abnormalities. Congenital portosystemic shunts were found in 61 dogs, of which 19 had intrahepatic shunts and 42 had extrahepatic shunts. Intrahepatic shunts originated from the left portal branch in 14 dogs and the right portal branch in 5. Extrahepatic shunts originated from the splenic vein, the right gastric vein, or both and entered the caudal vena cava or the thorax. Ultrasonography revealed splenic-caval shunts in 24 dogs, right gastric-caval shunts in 9 dogs, splenic-azygos shunts in 8 dogs, and a right gastric-azygos shunt in 1 dog.


CONCLUSIONS
Results suggest that ultrasonography is a reliable diagnostic method to noninvasively characterize the underlying disease in dogs with hyperammonemia. A dilated left testicular or ovarian vein was a reliable indicator of acquired portosystemic shunts.
Division of Diagnostic Imaging, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 10, 3584 CM, Utrecht, The Netherlands.
Viktor
V
Szatmári
Jan
J
Rothuizen
Ted S G A M
TS
van den Ingh
Frederik  J
F
van Sluijs
George
G
Voorhout
D000818:Animals; D016319:Corrosion Casting / Q000662:veterinary; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000151:congenital / Q000000981:diagnostic imaging* / Q000209:etiology; D004285:Dogs; D005260:Female; D022124:Hyperammonemia / Q000000981:diagnostic imaging / Q000209:etiology / Q000662:veterinary*; D007813:Laparotomy / Q000662:veterinary; D008099:Liver / Q000002:abnormalities / Q000000981:diagnostic imaging; D008297:Male; D011168:Portal System / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D018615:Ultrasonography, Doppler, Color / Q000662:veterinary