Perirenal Pseudocysts is the term used to describe an abnormal or dilated space resembling a cyst but not lined with epithelium, containing fluid. This condition is characterized by a capsule of accumulated fluid that causes one or both kidneys to enlarge. The capsule or sac is not a cyst as it lacks a true membrane covering. This rare disorder in dogs is mostly seen in older dogs.
Usually, the dogs remain asymptomatic (without any signs) but some dogs may manifest signs such as abdominal distention, excessive drinking and urinating, weight loss, poor appetite and vomiting.