Dr. Cindy Krane, DVM
Renal failure can be divided into two main categories: acute and chronic. Acute renal failure is defined as a sudden onset of failure which, if treated quickly and aggressively, can be reversed. Chronic renal failure is defined as progressive and irreversible disease process. This ongoing problem interferes with the ability of the kidneys to function properly. In the body, kidneys serve as a filter for the bloodstream. Toxins that are produced in the body are put in the urine to exit the body, and important electrolytes are kept in the bloodstream for further use. If the kidneys are experiencing difficulty functioning normally, there can be a build-up of toxins in the bloodstream, a condition known as “azotemia”. This does not indicate that the animal has a poor quality of life or feels sick; it simply means that the body is not currently functioning as it should. If this condition progresses, however, it can lead to a condition known as “uremia,” which means that the build-up of toxins has reached a level where the animal is now feeling poorly. By the time this condition is diagnosed, we can never get the kidneys to function at full capacity again. Treatment is centered around slowing the progression of the disease. Chronic renal failure is a terminal disease that progresses over months to years.
Typically, chronic renal failure occurs in dogs seven years of age or older. As a dog ages, it is more common to see this disease. Males and females are equally affected, and it can be seen more frequently in certain dog breeds, including: Beagles, Miniature Schnauzers, Cocker Spaniels, Shih Tzus, and Standard Poodles. Signs to look for at home include increased drinking, increased urination, loss of appetite and gastrointestinal signs.
In order to diagnose chronic kidney failure, bloodwork, a urinalysis (examination of the urine), and a bacterial culture of the urine is required. Unfortunately, bloodwork will not detect renal failure until ~ 75% of the functional mass is lost. Consequently, by the time it is diagnosed, the prognosis is fair to poor. Bloodwork may reflect the buildup of toxins in the bloodstream (increased BUN and creatinine), as well as the electrolyte changes and anemia. Radiographs may also be recommended, as a way to visualize the size and shape of the kidneys, and to assess the underlying cause of the disease. An ultrasound will also give further imaging to assess the kidneys and rule out other possible kidney diseases (such as cysts, cancer, kidney stones, or toxin damage).
At the time of diagnosis, your veterinarian may recommend hospitalization for intravenous fluids to rehydrate the patient and correct fluid and electrolyte imbalances. Medications to decrease nausea and increase appetite, antibiotics, red cell stimulants, blood pressure medications, and supplements may be prescribed. Once the pet is discharged from the hospital, subcutaneous fluids (fluids administered under the skin) and free access to plenty of fresh water is required. Dogs with kidney disease may also benefit from a diet with reduced protein, sodium, and phosphorus. Cutting edge technology and advances in veterinary care make kidney transplantation a possibility for some pets.
As with all diseases, animals need to be diagnosed and treated on a case-by-case basis, as no two animals and no two diseases are the same. As a dog becomes a senior citizen, it is recommended to visit the veterinarian every 6 months for a complete physical exam and laboratory testing. These simple visits can serve as an effective screening process to catch diseases early in their course. Early diagnosis of disease not only improves an animal’s treatment and helps delay the progression of disease, it greatly improves their quality of life and overall well-being.