STEP 4: PINPOINT THE CAUSE BASED ON DIAGNOSTIC TEST RESULTS
Table 1 summarizes possible causes of hematuria based on potential outcomes of the diagnostic algorithms for suspected urogenital
Table 1: Causes of Hematuria Based on Algorithm Findings and Localization of Urogenital Source
Exercise-induced hematuria may represent a rare subcategory of trauma that is diagnosed by excluding other causes of hematuria
and noting a history of vigorous exercise that occurred within minutes to a few days before blood became apparent in the urine.8,9 Exercise-induced hematuria, as described in people, is transient and is thought to be primarily related to bladder mucosal
damage that occurs as a result of repetitive or vigorous movement of the bladder during exercise. In some cases, the source
of exercise-induced hematuria may be nontraumatic and occur as a result of increased glomerular excretion of RBCs into the
Although uncommon, leakage of RBCs through the glomerulus can occur because of chronic congestive mechanisms resulting from
disorders such as heart failure8,12 or as a consequence of ischemic and congestive mechanisms associated with exercise-induced hematuria.11
Renal hematuria can fall in an idiopathic category. Primary (idiopathic) renal hematuria is thought to result from benign
vascular abnormalities that are not readily recognizable through typical diagnostic procedures.13-15
Handling patients with hematuria begins with confirming RBCs in the urine since a variety of pigmented substances can discolor
the urine. Hematuria can be confused with hemoglobinuria, myoglobinuria, bilirubinuria, and pseudohematuria. Once RBCs have
been confirmed, historical and physical examination findings can often localize the source of hematuria to the upper urinary
tract, lower urinary tract, or genital tract. Coagulopathies must be differentiated from disease of the urogenital tract as
the source of urine RBCs. After localizing the source of hematuria, you can follow a series of algorithmic steps delineating
a logical diagnostic plan to identify categories of disorders that can lead to a specific cause of hematuria.
Mary Bowles, DVM, DACVIM
Department of Veterinary Clinical Sciences
Center for Veterinary Health Sciences
Oklahoma State University
Stillwater, OK 74078
1. DiBartola SP. Renal disease: clinical approach and laboratory evaluation. In: Ettinger SJ, Feldman EC, eds. Textbook of veterinary internal medicine. 6th ed. St. Louis, Mo: Elsevier, 2005;1716-1730.
2. Chew DJ, DiBartola SP. Urinalysis interpretation. In: Interpretation of canine and feline urinalysis. Wilmington, Del: The Gloyd Group Inc, 1998;15-33.
3. Davies C, Shell L. Discolored urine. In: Common small animal diagnoses: an algorithmic approach. Philadelphia, Pa: Saunders, 2002;200-201.
4. Bartges JW. Discolored urine. In: Ettinger SJ, Feldman EC, eds. Textbook of veterinary internal medicine. 6th ed. St. Louis, Mo: Elsevier, 2005;112-114.
5. Chew DJ, DiBartola SP. Sample handling, preparation, and analysis. In: Interpretation of canine and feline urinalysis. Wilmington, Del: The Gloyd Group Inc, 1998;9-11.
6. McCarthy TC. Lower urinary tract endoscopy, in Proceedings. Western Vet Conf 2002.
7. Chew DJ, McLoughlin MA, Cannizzo K. Uroendoscopy in dogs and cats, in Proceedings. Western Vet Conf 2003.
8. Kaufman GM. Hematuria-dysuria. In: Ettinger SJ, ed. Textbook of veterinary internal medicine. 3rd ed. Philadelphia, Pa: WB Saunders Co, 1989;160-164.
9. Grauer GF. Clinical manifestations of urinary disorders. In: Nelson RW, Couto CG, eds. Manual of small animal internal medicine. St. Louis, Mo: Elsevier Mosby, 2005;368-377.
10. Gambrell RC, Blount BW. Exercise–induced hematuria. Am Fam Physician 1996;53(3):905–911.
11. Arbarbanel J, Benet AE, Lask D, et al. Sports hematuria. J Urol 1990;143(5):887-890.
12. Lorenz MD. Discolored urine. In: Lorenz MD, Cornelius LM, eds. Small animal medical diagnosis. Philadelphia, Pa: JB Lippincott Co, 1987;331-342.
13. DiBartola SP. Renal disease: clinical approach and laboratory evaluation. In: Ettinger SJ, Feldman EC, eds. Textbook of veterinary internal medicine. 6th ed. St. Louis, Mo: Elsevier, 2005;1716-1730.
14. Forrester SD. Diagnostic approach to hematuria in dogs and cats. Vet Clin North Am Small Anim Pract 2004;34(4):849-866.
15. Berent AC. Endourology and interventional radiology of the urinary tract, in Proceedings. Am Coll Vet Intern Med Forum 2007.