80% of what we do for our pets is to feed them. And realistically, eating is a large part of what we do as humans. Therefore it’s easy to blame ill health on diet. It certainly has been my focus for the last eight years – 80% of what walked in the door of my clinic could be fixed through good nutrition.
However, there comes a time when we have to think beyond an easy scapegoat and figure what is really going on. Case in point: a pet owner reached out to me recently that her three-year-old cat, to whom she has been feeding a raw diet since adoption, has abnormal blood work. This young cat has dilute urine and elevated blood kidney values. Her veterinarian immediately blamed the diet.
Certainly, it has been documented that a raw diet can cause slight increases blood levels of both creatinine and BUN (blood urea nitrogen) – after all, both of these are normal breakdown products of protein digestion. Ironically, a slight elevation in BUN and creatinine do not suggest the health of the animal has changed, it suggests the laboratory reference range needs to be adapted for the raw fed animal. Regardless, in healthy animals, while a raw diet can mildly elevate blood parameters of kidney function, the diet does not affect the kidneys ability to concentrate urine.
Kidneys are responsible for filtering the blood, excreting excess liquid and some waste products, while retaining important minerals for cellular function. In cats with normal renal function, the kidneys will produce relatively concentrated urine. (Urine concentration is measured by specific gravity and should be higher than 1.020.) Regardless of the diet. If the kidneys are not concentrating urine, it suggests something very serious is going on.
What is surprising to those who have not done the research, is that raw companies do have historical data regarding bloodwork and other health parameters. If these diets were causing kidney failure, these diets would have been removed from the marketplace years ago!
It is easy to blame something to which we do not agree. It takes a little bit more effort to evaluate the biological process to explain the allegation.
It may seem minor that this young cat is not concentrating its urine; except that kidneys’ important job is to help bodies conserve fluids. Cats are notorious for developing kidney issues; some cats are even born with defective kidneys which is why some of these wonderful creatures prematurely developed kidney failure. This particular concerned owner is intelligent and knows that a three-year-old cat should not have early signs suggesting kidney failure.
Traditional “solutions” include starting a prescription kidney diet. There are critical differences between feeding a prescription kidney diet and feeding a raw meat diet. These differences include protein level as well as ingredient quality.
The typical prescription kidney diet is low in protein. Logically, no protein intake results in low protein by-products in the output. Remember, from above, the kidneys’ job is to filter these protein by-products, BUN and creatinine. So if you don’t feel protein to a cat, the cat doesn’t lose protein in its urine due to failing kidney function. That makes sense.
But the next question to ask is what the protein is used for by the cat (any species really). Protein is used to build muscle. Not just body muscle, but heart muscle.
Think of the cats that you know of who are on a kidney diet. Hopefully, their weight is the same as it was before they went into kidney failure, but many of them have lost muscle mass. If we don’t feed protein, the body can’t rebuild muscle. These cats lose more and more muscle weight. But they may have excess body fat.
Because if you remove protein from the diet, it has to be replaced with something: the only choices are fat or carbohydrates. Neither fat nor carbohydrates are going to build muscle, but they contribute to excess body fat.
It is common in our society to consider the doctor to be the expert – certainly doctors and veterinarians have extensive training in how the body works. But it’s also vital to use common sense. It makes no sense for a three-year-old cat to be showing signs of kidney failure. It’s easy to blame a diet that is against conventional practice, but it’s not logical when the physiology is explained.
Every time an allegation is made for or against a food or product, the logic test must be applied.
In the case of this little kitty, I’ve encouraged the owner to return to her veterinarian and do more diagnostic testing to figure out what’s really going on. It’s very possible this little kitty was born with defective kidneys.
In order to extend his quality of life, it is critical to provide the highest quality nutrition possible so he has the best quality of life for as long as possible. Muscle wasting due to feeding a diet deficient in protein does not sound like quality of life to me.