Uterus unicornis and pregnancy in two feline littermates.

The complexity of uterus unicornis and renal aplasia is demonstrated by this unique presentation of five related cats for ovariohysterectomy. This report raises questions regarding the genetic, environmental, hormonal or other underlying causes of this anatomic abnormality in cats that may spur additional research. This is the first publication describing uterus unicornis in gravid feline littermates, with one of the cats having ipsilateral renal agenesis. This is also the first publication to describe oviduct agenesis on the affected uterine horn in feline uterus unicornis.