Cystitis is inflammation of the bladder. In most canine cases, cystitis is due to bacterial infection. Canine hemorrhagic cystitis, however, has no bacterial cause. Because no bacteria are present, it is often referred to as sterile hemorrhagic cystitis. Hemorrhagic cystitis is a rare side effect of certain chemotherapy drugs. Preventative measures can help reduce the risk.
Common symptoms of hemorrhagic cystitis include hematuria, dysuria and pollakiuria. Hematuria is blood in the urine. Often, this blood is not visible to the naked eye but seen in urinalysis. You may notice your pooch straining or having difficulty urinating. This is dysuria. Frequent urination, or pollakiuria, may cause your pet to urinate small, frequent dribbles.
Hemorrhagic cystitis is a complication of the chemotherapy drugs cyclophosphamide and ifosfamide. These drugs cause a chemical irritation to the mucous lining in the bladder due to the metabolites. Dogs with pre-existing immune deficiencies or history of urinary tract infections are at greater risk of developing hemorrhagic cystitis while taking these drugs.
Before treating hemorrhagic cystitis, a veterinarian needs to rule out bacterial causes. A urinalysis, a urine culture and sensitivity, and urinary tract imaging help to rule out a bacterial cause. If the veterinarian determines it is hemorrhagic cystitis due to the chemotherapy drugs, the use of the drug stops. There is no direct treatment of hemorrhagic cystitis; it usually clears up within a few days to a few months. Often anti-inflammatory drugs reduce the symptoms. If blood loss is severe, transfusions may be necessary.
The administration of additional drugs during chemotherapy treatments helps to reduce the risk of developing hemorrhagic cystitis. Furosemide is a diuretic designed to dilute the metabolites caused by the chemotherapy drugs. The sulfa drug mesna binds with the metabolites in the urine, reducing the risk of inflammation. During chemotherapy treatments, it is essential that your dog has free access to fresh water and has the opportunity to urinate frequently.
- VCA Animal Hospitals: Cystitis in Dogs
- Victorian Animal Cancer Care: General Recommendations for Management of the Common Side Effects of Chemotherapy
- Oncology for Veterinary Technicians and Nurses; Antony S. Moore and Angela E. Frimberger, editors
- Journal of the American Veterinary Association: Risk Factors for Sterile Hemorrhagic Cystitis in Dogs With Lymphoma Receiving Cyclophosphamide With or Without Concurrent Administration of Furosemide: 216 Cases (1990 - 1996)
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