Canine Renal Biopsy | Renal biopsy in dogs

Canine Renal Biopsy | Renal biopsy in dogs
The biopsy and histopathologic evaluation of renal tissue is a valuable diagnostic and prognostic tool. Renal biopsy in dogs and cats should be considered if the diagnosis is in question (e.g., immune complex glomerulonephritis versus amyloidosis in dogs with proteinuria), if treatment may be altered on the basis of results (e.g., confirmation and culture of bacterial pyelonephritis), or if the prognosis may be altered on the basis of results (e.g., evidence of reversible tubular lesion in a dog or cat with acute tubular necrosis). A specific diagnosis is required in order to implement specific treatment in most animals with renal disease, and for a specific diagnosis to be obtained, frequently a biopsy must be done. In addition, the prognosis for animals with renal disease is most accurate if based on three variables: the severity of disfunction, the response to treatment, and the renal histopathologic findings.

Renal biopsy in dogs and cats should be considered only after less invasive tests have been done and the blood clotting ability has been assessed. Contraindications to renal biopsy include a solitary kidney, a coagulopathy, severe systemic hypertension, and renal lesions associated with fluid accumulation (e.g., hydronephosis, renal cysts and abscesses). In addition, renal biopsy should not be attempted by inexperienced clinicians or in animals that are not adequately restrained.

Renal biopsy specimens can be obtained percutaneously using the keyhole technique or under laparoscopic or ultrasonographic guidance. Frequently the best way to obtain a specimen is at laparatomy when both kidneys can be visualized, because postbiopsy hemorrhage can then be accurately assessed and treated, and an adequate biopsy specimen assured. The cortical region of the kidney should be biopsied to obtain an adequate number of glomeruli in the specimen and to avoid renal nerves and major vessels in the medullary region. Most animals will have microscopic hematuria for 1 to 3 days after the biopsy procedure, and overt hematuria is not uncommon. Severe hemorrhage occurs less than 3% of the time and is almost always the result of faulty technique.