Introduction
Kidney disorders in dogs can occur for a variety of different reasons, and they can affect dogs in a number of different ways. Kidney diseases tend to be categorized into those that occur acutely and those that are more chronic in nature.
Chronic Kidney Disorders
Chronic renal disorders, often called chronic renal failure (CRF), results from long-term insult to the kidneys which, over time, damages their ability to adequately concentrate urine and remove nitrogenous wastes from circulation. Chronic kidney disease can be caused by trauma, congenital abnormalities, chronic urinary tract obstruction or infection, kidney stones, polycystic kidney disease, exposure to toxins (drugs, plants, venom, chemicals), lymphoma, and a number of kidney-specific disorders that your veterinarian can discuss with you if they pertain to your pet (glomerulonephritis, pyelonephritis, tubulonephrosis, amyloidosis, tubulointerstitial nephritis, etc.). Chronic kidney disorders are particularly devastating for owners because by the time clinical signs become apparent, the dog’s kidneys have already suffered severe and irreversible damage.
The clinical signs of chronic renal disease are a result of the body’s attempt to compensate for the kidneys’ diminishing ability to flush toxins out of the body. Among the early signs are “polyuria” and “polydipsia,” which mean dramatically increased volume of urine and excessive thirst manifested by increased water intake. Other signs that owners commonly notice are anorexia/inappetance, weight loss, vomiting, diarrhea, lethargy, halitosis (bad breath), seizures, bleeding/clotting problems, poor hair coat, weakness, depression and altered states of consciousness. In severe cases, affected dogs may develop high blood pressure (called hypertension), with the adverse effects associated with that condition.
Acute Kidney Disorders
The signs of acute kidney disorders appear abruptly. If appropriate treatment is provided quickly, it is possible to avoid permanent damage to the kidneys. Acute kidney disorders can be caused by venomous snake or insect bites, shock, bacterial and viral infections and exposure or ingestion of renal toxins such as antifreeze. The signs of acute-onset kidney disorders parallel those caused by chronic kidney damage and include lethargy, depression, vomiting, anorexia, collapse, abdominal discomfort, oral ulceration and bad breath. Another common sign is no urine production or no efforts by the dog to urinate.
If your dog is showing any of these signs, see your veterinarian as soon as you can. While chronic kidney damage is not reversible, acute renal damage can be treated if the cause of the insult is identified and rectified promptly. Your veterinarian will perform a series of tests, such as x-rays and blood tests, in order to assess kidney function and diagnose kidney disease.