Kidney Failure

Kidney failure is a common problem in dogs.

The kidney filters blood to remove waste products of digestion and metabolism. These wastes are then eliminated from the body through urine. Protein is broken down into urea, which makes up the main part of urine. When the kidney fails, wastes that are normally filtered out remain in the blood and build up, causing the dog to become ill.

The kidney also maintains the level of water in the body (hydration), and if the body is dehydrated, it concentrates the urine to retain as much water as possible. When the kidney fails, the dog produces dilute urine even when he is dehydrated, and has to in turn drink more water to stay hydrated.

Another important role that the kidney plays is the production of the hormone erythropoietin that stimulates the production of red blood cells. When the kidney starts to fail over a period of time, the dog becomes anemic.

Chronic kidney failure occurs mainly in older dogs. Breeds most at risk are:

• Cocker Spaniels
• Lhasa Apsos
• Shih Tzus
• Doberman Pinschers
• Soft-coated Wheaten Terriers
• Golden Retrievers
• Bull Terriers
• Cairn Terriers
• German Shepherds
• Samoyeds

Causes
Kidney failure can be caused by:

• Ingesting toxins (eg. anti-freeze, contaminated pet foods)
• Certain prescription medications (e.g. NSAIDs, gentamicin)
• Poor blood flow to the kidney (e.g. heart failure, general anesthesia)
• Inflammatory disease
• Infections
• Cancers
• Auto immune diseases

Symptoms

•  Increased thirstiness and increased consumption of water
• Urinating clear urine frequently and in large amounts
• Not urinating at all
• Lack of energy
• Weakness and depression
• Vomiting
• Bad breath
• Poor appetite

Diagnosis
A diagnosis of kidney failure can be achieved with:

• Complete medical history
• Physical examination
• Urine test (dilute urine in a dehydrated dog)
• Blood tests – Complete blood count (CBC) and biochemistry. Blood levels of urea, creatinine and phosphate are low but are increased in kidney failure and the kidney is unable to filter out these toxins. An abnormal build up of urea and creatinine is termed “azotaemia” and tend to make the dog feel very ill.

Other tests to help determine the cause of kidney failure may include:

• Ultrasound of the kidney
• Excretory urography
• Blood gas analysis
• Endogenous or exogenous creatinine clearance
• Urine protein/creatinine ratio
• Kidney biopsy

Treatment
Unfortunately, there is no cure for kidney failure. The damage is irreversible once done, hence why it is very important to get your dog to your vet as soon as you see symptoms. However, when this disease is diagnosed early, steps can be taken to slow the progression of the disease. Acute cases (of short duration but typically severe) are life threatening and require hospitalization. In chronic cases (persisting for a long time or constantly recurring), the patient will require hospitalization from time to time.

Treatments may include:

• IV Fluids to rehydrate and correct electrolytes abnormalities
• Providing a protein and phosphate restricted diet
• Symptomatic therapies such as anti-vomiting medication or appetite stimulants
• Blood dialysis
• Kidney transplant
• Erythropoietin to help treat anemia
• Daily home subcutaneous fluids

Prevention

• Select a puppy without a family history of kidney failure
• Provide access to fresh, clean water
• Avoid accidental access to toxins
• Have IV fluids to maintain blood pressure for general anesthesia