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Basics ⬇

Basics

Definition

Blood in urine

Pathophysiology

Secondary to loss of endothelial integrity in urinary tract, clotting factor deficiency, or thrombocytopenia.

Systems Affected

  • Renal/Urologic
  • Reproductive
  • Hemic/Lymphatic/Immune

Signalment

  • Dog and cat
  • Familial hematuria in young animals; neoplasia in older animals
  • Females at greater risk for UTI

Signs

Historical Findings

Red-tinged urine with or without pollakiuria

Physical Examination Findings

  • Palpable mass in patients with neoplasia
  • Abdominal pain in some patients
  • Enlarged and/or painful prostate gland in males
  • Petechiae or ecchymoses in patients with coagulopathy

Causes

Systemic

  • Coagulopathy
  • Thrombocytopenia
  • Vasculitis

Upper Urinary Tract

  • Anatomic-e.g., cystic kidney disease and familial malformations
  • Metabolic-e.g., nephrolithiasis
  • Neoplastic-e.g., renal lymphoma, adenocarcinoma, and hemangiosarcoma
  • Infectious-e.g., leptospirosis, FIP, and bacteria
  • Inflammatory-e.g., glomerulonephritis
  • Idiopathic
  • Trauma

Lower Urinary Tract

  • Anatomic-e.g., bladder malformations
  • Metabolic-e.g., uroliths
  • Neoplasia-e.g., transitional cell carcinoma and lymphosarcoma
  • Infectious-e.g., bacterial, fungal, and viral disease
  • Idiopathic-cats (idiopathic cystitis)
  • Traumatic
  • Cyclophosphamide-induced hemorrhagic cystitis

Genitalia

  • Metabolic-e.g., estrus
  • Neoplastic-e.g., transmissible venereal tumor, leiomyoma, and prostatic adenocarcinoma
  • Infectious-e.g., bacterial and fungal disease
  • Inflammatory-e.g., benign prostatic hyperplasia
  • Trauma

Risk Factors

Breed predisposed to urolithiasis (e.g., Dalmatians and urate urolithiasis), coagulopathy (e.g., Dobermans and von Willebrand disease), or neoplasia (e.g., Scottish terriers and transitional cell carcinoma).

Diagnosis ⬆ ⬇

Diagnosis

See Figure 1.

Differential Diagnosis

Other causes of discolored urine (e.g., myoglobinuria, hemoglobinuria, and bilirubinuria)

Laboratory Findings

Drugs That May Alter Laboratory Results

Substantial doses of vitamin C (ascorbic acid) may cause false-negative reagent test strip results; newer generations of reagent strips are more resistant to interference by reducing substances such as ascorbic acid.

Disorders That May Alter Laboratory Results

  • Common urine reagent strip tests for blood are designed to detect red blood cells, hemoglobin, or myoglobin.
  • Low urine specific gravity (polyuric syndromes) lyses RBCs.
  • Bacteriuria (bacterial peroxidase) causes false-positive reagent test strip results.
  • Formalin preservative causes false-negative reagent test strip results.

Valid if Run in a Human Laboratory?

Yes

CBC/Biochemistry/Urinalysis

  • Thrombocytopenia and severe anemia in some patients.
  • Azotemia in some patients with bilateral renal disease.
  • RBCs (>5–10 RBC/hpf) and possibly infectious agents seen in urine sediment.
  • Crystalluria in some patients with urolithiasis.

Other Laboratory Tests

  • ACT or clotting profile to rule out coagulopathy.
  • Bacterial culture of urine to identify urinary tract infection.
  • Examination of an ejaculate to identify prostatic disease.

Imaging

Ultrasonography, radiography, and possibly contrast radiography are often useful in localizing the underlying cause.

Diagnostic Procedures

  • Biopsy of mass lesion
  • Vaginourethrocystoscopy in females or urethrocystoscopy in males and females

Treatment ⬆ ⬇

Treatment

Medications ⬆ ⬇

Medications

Drug(s) Of Choice

  • Blood transfusion may be necessary if patient is severely anemic
  • Crystalloids to treat dehydration
  • Antibiotics to treat urinary tract infection and septicemia
  • Heparin for DIC

Contraindications

Immunosuppressive drugs, except to treat immune-mediated disease.

Possible Interactions

Intravenous contrast media can cause acute renal failure.

Follow-Up ⬆ ⬇

Follow-Up

Patient Monitoring

Depends on primary or associated diseases

Possible Complications

  • Anemia
  • Hypovolemia if severe hemorrhage
  • Ureteral or urethral obstruction due to blood clots

Miscellaneous ⬆

Miscellaneous

Age-Related Factors

  • Neoplasia tends to occur in older animals
  • Immune-mediated diseases tend to occur in young adult animals

Zoonotic Potential

Leptospirosis

Abbreviations

  • ACT = activated clotting time
  • DIC = disseminated intravascular coagulation
  • FIP = feline infectious peritonitis
  • RBC = red blood cell
  • UTI = urinary tract infection

Author Joseph W. Bartges

Consulting Editor Carl A. Osborne

Client Education Handout Available Online

Suggested Reading

Bartges JW. Discolored urine. In: Ettinger SJ, Feldman EC, eds., Textbook of Veterinary Internal Medicine, 7th ed. St. Louis: Elsevier, 2008, pp. 164–168.