WHAT IS KIDNEY DISEASE?

Kidney disease in dogs can affect any breed at any stage in their life and sadly, there is no way of predicting which will develop it and which will not. Although there is nothing you can do to actually prevent your four-legged friend from developing kidney failure in dogs, feeding them a good quality diet throughout their life, and providing them with a constant supply of fresh, clean water will help support their kidneys and, if they do develop kidney failure, it could help to slow down its progress.

Just like human kidneys, your dog’s kidneys balance certain substances in the blood and filter out the body's wastes as urine. They maintain normal concentrations of salt and water in the body. Kidneys also help control blood pressure, aid in calcium metabolism and sustain phosphorous levels. Additionally, they manufacture a hormone that encourages red-blood cell production. When kidneys don't function properly, toxins build up in the blood and a dog will become ill.

THERE ARE 2 TYPES OF KIDNEY FAILURE:

ACUTE KIDNEY (RENAL) FAILURE:  

A sudden loss of function. This occurs so suddenly that the functioning nephrons don't have time to compensate. Acute kidney failure is often reversible if diagnosed in the early stages and treated aggressively.

CHRONIC KIDNEY (RENAL) FAILURE: 

A loss of function that occurs gradually over months or years. The kidneys lose their ability to filter the blood of wastes. CRF can lead to total kidney failure.

WHAT CAUSES KIDNEY FAILURE IN DOGS?

There are many ways for the nephrons to become damaged:

ACUTE

•          Ingestion of harmful substances such as antifreeze and rat poison
•          Cancer
•          Heart failure
•          Hypotension (low blood pressure)
•          Clotting disorders
•          Intestinal disease
•          Dehydration
•          Bacterial infection (bacteria invade the urinary tract and travel to the kidneys)
•          Certain medications (some antibiotics and chemotherapy drugs)

CHRONIC

•          Autoimmune diseases (the immune system attacks the body's organs)
•          Cysts in the kidneys which grow and destroy tissues
•          Genetics

IS AGE A FACTOR OF CHRONIC KIDNEY DISEASE?

The most common form of chronic kidney failure is the result of aging; it is simply a “wearing out” process. The age of onset is related to the size of the dog. For most small dogs, early signs of kidney disease occur at about 10 to 14 years of age. However, large dogs have a shorter age span and may go into kidney failure as early as seven years of age.

WHAT ARE THE SYMPOMS OF KIDNEY FAILURE?

•          Depression
•          Dehydration
•          Excess thirst
•          Lack of appetite and weight loss
•          Vomiting (may contain blood)
•          Diarrhea (may contain blood)
•          Weakness
•          Foul-smelling breath
•          Seizures

Some additional signs:

Acute:

•          Stiff-legged gait and arched back (a sign of painful kidneys)
•          Frequent or no urination

Chronic:

Chronic disease progresses over a period of years and can go unnoticed. When signs finally appear, the disease is already advanced. But with proper treatment, some dogs with chronic kidney failure live comfortably for years after diagnosis.

•          Increased urination
•          Bleeding or bruising easily

HOW TO DIAGNOSE KIDNEY FAILURE IN DOGS?

Blood and urine tests are used to diagnose acute kidney failure and to assess the severity of disease. Other tests, such as radiographs (X-rays), ultrasound and special blood tests are usually necessary to help determine what might have caused the kidney failure. Sometimes a biopsy of the kidney is recommended.

HOW IS KIDNEY FAILURE TREATED?

It is important to identify kidney failure and begin treatment in its earliest stage. Your veterinarian can determine if kidney disease is present and start appropriate treatment. Depending on whether the problem is acute or chronic, treatment may include the following:

 • Drugs that encourage urine production

• Fluid therapy

• Management of blood electrolyte abnormalities

• Monitoring of urinary output

• Control of vomiting

• Medication for gastrointestinal problems

• Dialysis

• Dietary management

• Correction of anemia

• Management of high blood pressure

• Therapy for any specific underlying causes identified (example: antifreeze toxicity, infection)

WHAT CAN DO TO PREVENT KIDNEY FAILURE IN MY DOG?

• Ensure that your dog drinks plenty of water, especially if they have been physically active.
• To prevent kidney problems due to poisoning, make sure your dog does not have access to potentially dangerous substances and that she is supervised at all times when outside
• Regular veterinary exams and lab work, especially in older or high risk dogs
• Do not breed dogs with hereditary causes of kidney failure

Hopefully the guide above has provided some insight into the realities of kidney failure in dogs. If you notice any of the symptoms as described above, then it is advisable to take your dog to visit a vet as soon as possible.

NUTRITION FOR DOGS WITH KIDNEY DISEASE

Water. Diseased kidneys are not as effective at excreting waste products from the body through the urine. One consequence of CKD is a decreased ability of the kidneys to concentrate the urine. In order to continue to rid the body of its toxins despite more dilute urine, the body compensates by stimulating greater thirst. This makes it critical for you to provide your dog with an unlimited supply of fresh water. Canned food can help increase your dog's intake of moisture. To encourage more water intake, change your pet’s water several times a day and clean your pet’s water bowl daily.

Protein. Decreased dietary protein appears to slow the progression of CKD by decreasing the workload on the kidneys to excrete protein waste products. Less protein also means less need for the excretion of protein itself through the filtration mechanism of the kidney, which helps preserve kidney function. The recommended range of protein on a dry matter basis for dogs with CKD is less than or equal to 14-20%.

Phosphorus. Limiting dietary phosphorus in dogs with CKD appears to help delay the progression of CKD, although the precise mechanism is unknown. The recommended phosphorus range on a dry matter basis for dogs with CKD is 0.2-0.5%. Since phosphorus content is related to protein content, it is impossible to achieve these lower levels of phosphorus without limiting protein content.

Sodium. Dietary sodium levels are mildly restricted to reduce the workload on the kidneys. This in turn helps to maintain a reasonable blood pressure.

Omega-3 fatty acids. Dietary omega-3 fatty acids help reduce the production of inflammatory compounds that create oxidative stress to the tissue of the diseased kidneys, thus contributing to slowed progression of CKD. This works by reducing protein 'leaking' through the kidneys.