Perirenal pseudocysts in 26 cats

Objective To evaluate clinical features, anatomical location, nature of pse udocyst fluid, results of surgical treatment and links with underlying rena l disease in cats with perirenal pseudocysts. Design A retrospective study of 26 affected cats, including 8 treated surgi cally. Results Nineteen (73%) affected cats were male. The median age was 11 years . Most presented for abdominal enlargement and had varying degrees of renal dysfunction on presentation. Thirteen cats (50%) had bilateral pseudocysts . The pseudocyst fluid was a transudate or modified transudate in all cases . All surgically treated cats had subcapsular perirenal pseudocysts. Associ ated renal lesions were identified in all cats that had renal biopsies or d etailed ultrasonographic examinations. Surgery relieved clinical signs but did not stop progression of renal disease. Cats survived a median of 9 mont hs after surgery and survival was correlated statistically to degree of azo taemia at presentation. Percutaneous drainage of pseudocysts was ineffectiv e in controlling long-term fluid accumulation. Conclusions Subcapsular perirenal pseudocysts are formed in cats by accumul ation of transudate between the capsule and parenchyma of the kidney as a r esult of underlying parenchymal disease. Pseudocyst formation can occur at variable stages of renal dysfunction. Resection of the pseudocyst wall is u sually effective in eliminating signs but does not stop progression of rena l disease. The prognosis for cats with pseudocyst formation is related to t he degree of renal dysfunction at time of diagnosis.