Urogenital disorders of ferrets and rabbits (Proceedings)
Although many diseases of the urinary and genital systems are similar in many aspects in all mammals, there are features and presentations which are unique to certain species. Ferrets and rabbits each have specific disease presentations, and the understanding of these disorders is essential in recognizing normal and abnormal, and treating these pets. Although diagnostic evaluation is similar, etiologies, interpretation of laboratory results, and therapeutic strategies may vary substantially. A thorough understanding will lead to the most rapid, effective treatment plan.
AnatomySimilar to that of other mammals. Kidneys are usually radiographically evident in the retroperitoneal space in both species, surrounded by fat. Rabbit kidneys may be radiographically located more ventrally than usual due to the presence of retroperitoneal fat. The bladder is cranial to the pelvic inlet and easily palpable when full.
When azotemia is present, determine whether prerenal, renal, or postrenal. Assess chronicity and duration of renal disease.
Assess hydration, renal discomfort, kidney size and shape, presence of other abdominal masses, and urinary obstruction.
Essential in evaluation of the urinary system – polyuria, hematuria, casts, proteinuria, crystalluria, or isosthenuria accompanying dehydration all are indicators of urinary disease. Normal urine pH values in carnivores are acidic, and are alkaline in herbivores. Microcytic, hypochromic, nonregenerative anemia, hyperphosphatemia, hypocalcemia, and metabolic acidosis often accompany chronic renal failure.
Radiographs are ideal for detection of calculi (bladder, renal, urethral, or ureteral) or calciuria, as well as prostatic or uterine enlargement. Excretory urography (IVP-Intravenous pyelography) is useful to detect obstruction and hydronephrosis, and to evaluate renal perfusion. Contrast cystography can be used as in other species for evaluation of the bladder and urethra. Both sexes of rabbits can be easily catheterized; male ferrets, however, are extremely difficult to catheterize and always require sedation. There is a j-shaped os penis, which is exteriorized by placing pressure on the base of the penis, and the urethral opening is not quite at the distalmost aspect of the penis. Female ferrets are extremely difficult to catheterize.
An excellent diagnostic tool for evaluating the renal system as well as other organs. Also enables aspirates of masses or fluid-filled structures, and can be used to guide renal biopsies. (Note: due to the small patient size, there can be increased risk of injury to the renal vessels in small patients.)
Can be used to determine glomerular filtration rate (GFR) in mammals, and can assess each kidney individually. This is the most accurate assessment of renal function. Although not yet described for ferrets or rabbits, this is an emerging technique in veterinary medicine which enables assessment of GFR in each kidney individually with no patient risk other than anesthesia. (Note: the author has performed GFR scans in ferrets and in rabbits, although there are no published normal values for comparison.)
Renal or bladder biopsy is performed as in other species.