November 10, 2009

What problems affect the kidneys of pets and how can we tackle them?

Kidney or renal failure, kidney disease and impaired renal function, are all conditions of varying severity, that affect a worrying number of modern domesticated cats and dogs. It has become a leading cause of death in pets over age ten.

The job of the kidneys is to filter the blood and remove waste from the body, via the urine. When the kidneys don’t function properly, the nephrons (tiny filters within the kidneys) fail to filter the blood and so waste remains in the bloodstream.

Symptoms of kidney disease include:

  • Increased water intake
  • Increased urination
  • Fluid retention (sometimes causing an overweight appearance)

    • In kidney failure, blood test results will indicate elevated BUN (blood urea & nitrogen) as well as increased creatinine and phosphorus levels.

      The incidence of kidney disease in the United States has been increasing at an alarming rate in recent decades, particularly in cats. There has been a great deal of speculation about the cause and as with most things, a number of factors including vaccines, genetics and nutrition are all thought to play a role, but increasingly, poor quality pet food is being called into question.

      The effects food

      Cats and dogs are physiologically designed to consume meat as their main source of nutrition. Fresh meat is the most biologically appropriate choice and food that is moist when served is much less troublesome for the kidneys to process, than dry baked or kibbled food.

      In the long term, a diet that consists of very low moisture with a biologically inappropriate poor quality protein (by-products) as well as toxic preservatives like BHA, BHT and Ethoxyquin, will tax the kidneys and in a susceptible pet, and this can result in impaired renal function, renal disease and true kidney failure – causing severe pain and discomfort for the patient.

      Many conventional vets have historically recommended that cats and dogs with kidney disease be fed a diet that is worryingly low in protein. The theory is that these specially formulated “kidney diets” with their highly restricted protein, will be helpful for the kidneys whose role is to process this protein for use by the body. Less protein, the theory goes, will tax the kidneys less. But the fact is that cats and dogs need high protein and despite these low protein kidney diets being fed, no increase in survival rates has been documented.

      Dogs and cats with kidney disease or some level of kidney failure need a pet food diet that has moderate protein which is easily digestible. A diet that contains very low protein in the form of by products like beaks, feet and feathers is actually even more difficult for the kidneys to assimilate than one with more protein in a pure, highly digestible form. Keeping the percentage of meat about the same but using a fattier meat may be helpful as well.

      In addition to easy-to-digest protein, a pet with kidney disease also needs sufficient vegetables or other fiber to bind with phosphorus in the digestive tract, and adequate vitamins and minerals. Keeping the pet lean and supplementing with glandular extracts is also helpful and recommended by many holistic vets.