Numerous locations have been reported for vegetal foreign body migration. However, urogenital migration has rarely been documented. In this retrospective study, the ultrasonographic features associated with intrauterine migrating vegetal foreign bodies (grass seeds) are described in one intact and ten ovariectomized bitches. The most common ultrasonographic finding was focal and mild ampullary dilation of the uterus, containing the foreign body outlined by scant intraluminal fluid. There were no changes seen to the uterine wall, except in one dog with uterine perforation, confirmed at surgery. The remainder of the uterus had a normal appearance in 8/11 dogs, while there was a small amount of intraluminal fluid in 2/11 cases. Mild, focal steatitis around the focal dilation of the uterus segment containing the foreign body was observed in one case. The subtlety of these findings suggests that the ultrasonographic diagnosis of uterine grass awns can be challenging. This underlines a discrepancy with other reported migration sites commonly associated with marked inflammation.