Kidney (renal) problems in dogs

Written by Kate Abbott Reviewed by Kristin Westafer, DVM

Overview

The kidneys are very important organs. They have multiple functions in the body including filtering and eliminating waste from the blood, producing urine, and regulating blood pressure. The kidneys also produce a hormone, erythropoietin, that is responsible for stimulating the bone marrow to produce red blood cells. Vitamin D is also activated by the kidneys and is very important for proper calcium absorption from the gastrointestinal tract.

Within the kidneys are tens of thousands of microscopic tubes called nephrons. Nephritis is an inflammation of the nephrons, and nephrosis is when the nephrons are damaged. Nephrons can be damaged by many causes such as aging, poisons, infection, trauma, cancer, auto-immune diseases, and genetic predisposition. Kidney failure can result from low grade, long term inflammation of the kidney tissues called chronic nephritis.

Two common types of dog kidney problems are chronic renal failure and acute renal failure. Chronic renal failure, the most common form of renal disease in dogs, affects an estimated one in five elderly dogs, and is usually caused by some other illness, often age-related. Acute kidney failure is most often the result of ingesting toxins (such as antifreeze and certain types of rat poison), but can also result from viral infections, poor nutrition, immune deficiencies, kidney stones, rupture of the bladder, congestive heart failure, or genetic disorders.

Kidney disease is the second leading cause of death in dogs (cancer is the first). Renal diseases are common and seen in more than thirty breeds of dogs:

Airedale Terriers
Alaskan Malamutes
Basenjis
Beagles
Bedlington Terriers
Boxers
Bulldogs
Bull Terriers
Cairn Terriers
Cavalier King Charles Spaniels
Chinese Shar-Peis
Chow Chows
Cocker Spaniels
Collies
Doberman Pinschers
Flat-coated Retrievers
Golden Retrievers
Great Danes
Great Pyrenees
Irish Wolfhounds
Keeshonds
King Charles Spaniels
Lhasa Apsos
Miniature Poodles
Miniature Schnauzers
Newfoundlands
Norwegian Elkhounds
Old English Sheepdogs
Pekingeses
Samoyeds
Shetland Sheepdogs
Shih Tzus
Soft-Coated Wheaten Terriers
Standard Poodles
Swedish Foxhounds
Tibetan Spaniels
Tibetan Terriers
Welsh Corgis
Yorkshire Terriers

Symptoms

Clinical signs are often missed during the early stages of kidney disease because the changes are very subtle. When a dog has renal insufficiency, 66% of their kidney function is lost and they produce very dilute urine. As renal insufficiency progresses to kidney failure, greater than 75% of their kidney function is lost. Dogs with renal failure often feel poorly and decline because of the increased amount of waste products in their blood.

Excessive water consumption and urination are the two main signs that a dog may be suffering from kidney disease. Chronic renal failure can progress over a period of years with the signs of kidney problems going unnoticed until the disease is often well-advanced. Symptoms of kidney disease can include:

Drinking excess amounts of water
Frequent urination (urine is often very dilute and voided in large amounts)
Urinating in the house, especially if previously housetrained
Vomiting
Dehydration
Anorexia
Weight loss
Weakness, lethargy, and/or exercise intolerance
Tendency to bleed or bruise easily
Stiff-legged gait and arched back (a sign of painful kidneys)
Bleeding from the gums
Extremely bad breath (uremic breath
Complete lack of urine production (acute kidney disease)

Prevention

There are no specific ways to prevent kidney failure, but general recommendations include allowing your dog frequent opportunities to urinate and providing access to fresh, clean water at all times. Be aware of and prevent your dog from having access to toxins, such as antifreeze and other poisons.

Treatment

Your veterinarian should be consulted for treatment recommendations, but intravenous fluid therapy is usually the first course of treatment. Dogs with kidney disease often lose too much fluid through urine and are therefore at a very high risk for dehydration. Nutritional and fluid therapies can ease the work load of the kidneys by limiting and diluting the toxins that the kidneys must filter.

Dietary management can also help manage kidney problems. This consists primarily of restricting the amount of protein, phosphorus, and sodium in the diet, while providing adequate amounts of non protein calories, vitamins, and minerals. Consult with your veterinarian, as low-protein diets, if not carefully managed, can lead to malnutrition.

Dialysis and even kidney transplants are now available options for dogs with kidney disease, although often prohibitively expensive. Kidney dialysis for dogs is offered at several veterinary medical sites. The University of California, Davis, Veterinary Medical School is performing kidney transplants, but transplanted kidneys in dogs are commonly rejected.