Bilateral renal hypoplasia in feline

Abstract

Renal hypoplasia occurs when there is incomplete development of the kidney, resulting in fewer nephrons, lobes and calyces at birth. The severity of this anomaly depends on the level of involvement. When unilateral, compensatory hypertrophy of the healthy kidney occurs and, in bilateral cases, renal failure and infections are frequent. It has been portrayed as an inherited condition in some pure or mixed breeds of pigs, foals, goats, cattle and dogs, however, it is uncommon in felines. This paper aims to report the case of a feline, mixed breed, two months old, with complaints of apathy, anorexia and emesis for three days. Physical examination showed an estimated dehydration of 10%, capillary refilling time of three seconds, hypothermia, hypoglycemia and lethargy. In view of these changes, complementary exams were requested to better clarify the condition. Biochemical examinations revealed severe azotemia and hyperphosphatemia, as well as hypercalcemia and mild hyperkalemia. Urinalysis, on the other hand, indicated a reduction in urinary density associated with the presence of hyaline and brain cylinders. Abdominal ultrasound showed a loss of corticomedullary differentiation and a decrease in both kidneys, changes compatible with nephropathy. Palliative treatment was instituted in order to minimize secondary complications of acute kidney injury, however, the patient died. At necropsy, the kidneys were bilaterally reduced in size and histopathological examination revealed the presence of moderate multifocal primitive glomeruli associated with distention of the glomerular space. Clinical evaluation and histopathological lesions were consistent with the diagnosis of congenital renal hypoplasia.