Image Quiz: Ultrasonography-A cat with a distended abdomen

A 12-year-old spayed female domestic shorthaired cat is presented for increased urination. On abdominal palpation, the abdomen is diffusely distended and uncomfortable. You investigate with an ultrasonographic examination and see this image. What is your interpretation?

a) Transudate ascites

b) Bladder mass on the cranioventral bladder wall

c) Perinephric pseudocyst

d) Ureterocele