Hematuria in a Dog

Katy, an 8-year-old spayed female Scottish terrier, presented with a vague history of intermittent hematuria over the past 6 months.

History. Previous episodes of hematuria were treated with antibiotics and resolved in several days. Further workup was not completed during the prior episodes. The current problem had been ongoing for nearly a week and did not improve with antibiotic therapy.

Physical Examination. Katy was in good condition and was active and playful. Abdominal palpation was normal and physical examination revealed no abnormalities.

Laboratory Evaluation. A complete laboratory profile consisting of a hemogram, urinalysis, and serum biochemical panel was performed. The biochemistry results were unremarkable as were numbers of white blood cells. Other hemogram and urinalysis results are in the Table. Morphologic characteristics of the urine sediment are shown in Figures 1 and 2.

ASK YOURSELF ...• What is the interpretation of the hemogram?• What is the interpretation of the urinalysis?• What are the most likely differential diagnoses?• What additional tests will help make the definitive diagnosis?

Diagnosis: Transitional cell carcinoma

Cytology. Morphologic changes, such as those shown in the figures on the previous page, are suspicious for neoplasia. In these cases, an air-dried, Romanowsky-stained sediment smear should be made and microscopically evaluated.

Cytologic preparations of urine sediment are made by placing a drop of sediment at one end of a slide. Continue to prepare the slide the same way as a blood film is made. The air-dried film is stained with a routine Romanowsky (hematologic) stain such as Wright's stain or Diff-Quik.

The urine sediment smears shown in Figures 3 through 5 reveal clumps of epithelial cells that are morphologically consistent with transitional cells. These cells exhibit anisokaryosis (variable nuclear size), giantism, variable nuclear/cytoplasmic ratios, abnormally clumped chromatin patterns (Figure 4), and abnormal mitotic figures (Figure 5). The presence of more than 4 nuclear criteria of cancer leads to a likely diagnosis of transitional cell carcinoma.

Ultrasonography demonstrated a mass in the trigone of the bladder, which supported the cytologic diagnosis. When all of the findings are considered collectively, the presumptive diagnosis is transitional cell carcinoma of the bladder with associated secondary bacterial cystitis and blood-loss anemia. This can be confirmed via biopsy and histopathologic evaluation.

Discussion. Tumors of the urinary bladder are uncommon in dogs. However, transitional cell carcinoma is the most common primary tumor of the urinary bladder, and there is a higher incidence in older Scottish and West Highland white terriers, Shetland sheepdogs, and dachshunds.

Clinical signs such as hematuria, dysuria, pollakiuria, and stranguria in any combination suggest the possibility of transitional cell carcinoma. Diagnostic evaluation begins with a thorough physical examination, which should include abdominal palpation and rectal examination. Laboratory findings vary and may include azotemia. If urine sediment contains large numbers of epithelial cells, Romanowsky-stained, air-dried preparations should be evaluated for criteria of cancer. Cytologic diagnosis can be confirmed either with double-contrast cystography or ultrasonography.

In dogs, transitional cell carcinoma is an aggressive neoplasm, which usually arises in the trigone area. Obstruction of the ureters and/or growth down the urethra are common local and life-threatening complications. These tumors are also highly metastatic. Up to 40% have metastasized by the time of initial diagnosis.

Treatment depends on presentation. If cancer is localized, complete surgical excision is preferred. If complete excision is not possible, a combination of partial resection and medical management is usually followed. Current treatment recommendations are for piroxicam alone (0.3 mg/kg PO Q 24 H) or piroxicam combined with mitoxantrone (5 mg/m2 IV Q 21 D). Radiation therapy may also be useful. Response to therapy varies, but survival rates with medical treatment alone rarely exceed 12 months.

DID YOU ANSWER ...• Marginal lymphopenia and marginal eosinopenia (both at the low end of the reference interval) indicate a stress leukogram associated with high circulating glucocorticoids. The low hematocrit, red cell count, and hemoglobin all indicate anemia. The moderately elevated reticulocyte count indicates regenerative anemia (either from blood loss or hemolysis). The high-normal MCV and low MCHC are both consistent with mild to moderate regenerative anemia. Given the history, degree of regeneration, and absence of indicators of hemolysis (eg, spherocytes, Heinz bodies), this is probably a case of blood-loss anemia.• Increased red and white blood cells in urine indicate inflammation. Coupled with the bacteria, there is evidence of urinary tract infection. The large number of epithelial cells in clumps in a voided sample is unusual and suggests a proliferative process, either hyperplasia or neoplasia.• The most likely diagnoses are either proliferative bacterial cystitis with associated blood-loss anemia or transitional cell carcinoma with associated bacterial cystitis and blood-loss anemia.• Cytologic evaluation of stained air-dried preparations of urine sediment and ultrasonography of the bladder are indicated. Biopsy and histopathologic evaluation may be needed to confirm the diagnosis.

HEMATURIA IN A DOG • A. H. Rebar

Suggested ReadingCanine transitional cell carcinomas. Mutsaers AJ, Widmer WR. J Vet Intern Med 17:136-144, 2003.Urogenital and mammary gland tumors. Chun R, Garrett L. In Ettinger SJ, Feldman EC (eds): Textbook of Veterinary Internal Medicine, 6th ed-St. Louis: Elsevier, 2005, pp 784-785.