Mld. Cuypers et al., RENOMEGALY IN DOGS AND CATS .1. DIFFERENTIAL DIAGNOSES, The Compendium on continuing education for the practicing veterinarian, 19(9), 1997, pp. 1019
Detection of renomegaly is important because, when combined with other
clinical information (such as signalment and history), it provides a
narrow list of differential diagnoses. Clinicians who are familiar wit
h the potential causes of renomegaly can often quickly arrive at a def
initive diagnosis with the aid of radiographic, ultrasonographic, cyto
logic, or histopathologic information. Renomegaly is caused by various
pathophysiologic processes, such as infiltration of the renal parench
yma by inflammatory or neoplastic cells, alteration of renal structure
by developmental disorders or renal insult, and distortion of the col
lecting system secondary to urinary tract obstruction. In this review,
the causes are grouped into several categories for ease of discussion
: renomegaly caused by diffuse renal parenchymal disorders, such as ac
ute renal failure, amyloidosis, renal lymphoma, pyogranulomatous nephr
itis secondary to feline infectious peritonitis, and renal hypertrophy
; renomegaly caused by focal or multifocal parenchymal disorders, such
as polycystic kidney disease and primary or metastatic renal neoplasi
a; renomegaly caused by subcapsular and perirenal disorders, such as p
erinephric pseudocysts and subcapsular and perirenal hematomas and abs
cesses; and renomegaly caused by collecting system disorders, such as
hydronephrosis and acute bacterial pyelonephritis. Part II of this rev
iew will focus on the diagnostic approach to patients with renomegaly.