Distribution of extrahepatic congenital portosystemic shunt morphology in predisposed dog breeds.
BACKGROUND
An inherited basis for congenital extrahepatic portosystemic shunts (EHPSS) has been demonstrated in several small dog breeds. If in general both portocaval and porto-azygous shunts occur in breeds predisposed to portosystemic shunts then this could indicate a common genetic background. This study was performed to determine the distribution of extrahepatic portocaval and porto-azygous shunts in purebred dog populations.


RESULTS
Data of 135 client owned dogs diagnosed with EHPSS at the Faculty of Veterinary Medicine of Utrecht University from 2001 - 2010 were retrospectively analyzed. The correlation between shunt localization, sex, age, dog size and breed were studied. The study group consisted of 54 males and 81 females from 24 breeds. Twenty-five percent of dogs had porto-azygous shunts and 75% had portocaval shunts. Of the dogs with porto-azygous shunts only 27% was male (P = 0.006). No significant sex difference was detected in dogs with a portocaval shunt. Both phenotypes were present in almost all breeds represented with more than six cases. Small dogs are mostly diagnosed with portocaval shunts (79%) whereas both types are detected. The age at diagnosis in dogs with porto-azygous shunts was significantly higher than that of dogs with portocaval shunts (P < 0.001).


CONCLUSIONS
The remarkable similarity of phenotypic variation in many dog breeds may indicate common underlying genes responsible for EHPSS across breeds. The subtype of EHPSS could be determined by a minor genetic component or modulating factors during embryonic development.
Department of Clinical Sciences of Companion Animals, Utrecht University, Faculty of Veterinary Medicine, Utrecht, The Netherlands.
Lindsay
L
Van den Bossche
Frank G
FG
van Steenbeek
Robert P
RP
Favier
Anne
A
Kummeling
Peter A J
PA
Leegwater
Jan
J
Rothuizen
D000818:Animals; D004283:Dog Diseases / Q000151:congenital* / Q000000981:diagnostic imaging / Q000235:genetics; D004285:Dogs; D005260:Female; D020022:Genetic Predisposition to Disease; D008297:Male; D010641:Phenotype; D011168:Portal System / Q000002:abnormalities* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014463:Ultrasonography; D054079:Vascular Malformations / Q000000981:diagnostic imaging / Q000235:genetics*