Veterinary nutritionists and pet food company representatives will argue that they are smart enough to know *exactly* what is missing from a plant in terms of nutrient forms and amounts - nutrients that would otherwise be in a meat-based diet. They will then claim that these missing elements are added to their diets
to make it complete and balanced to sustain life in an obligate carnivore.
The problem with this way of thinking is that Man is just not that smart and has made fatal errors in the past when trying to guess how to compensate for such a drastic deviation from nature. Not all that long ago (1980s) cats were going blind and dying from heart problems due to Man's arrogance. It was discovered in the late 1980s that cats are exquisitely sensitive to taurine deficiency and our cats were paying dearly for Man straying so far from nature in order to increase the profit margin of the pet food manufacturers
There are several situations that can lead to a diet being deficient in taurine but one of them is using a diet that relies heavily on plants as its source of protein. Instead of lowering their profit margin and going back to nature by adding more meat to the diets, the pet food companies simple started supplementing their diets with taurine.
This is all well and good - for this particular problem - but how do we know that Man is not blindly going along unaware of another critical nutrient that is missing from a plant-based diet? Why is Man so arrogant that he thinks he can stray so far from what a cat is designed by nature to eat?
Let's also ask ourselves how many cats become ill or die from these species-inappropriate diets yet the patient's diet is never even questioned as a possible cause of the illness or death? We cannot answer that question definitively but I have no doubt that the answer would be "many".
Do cats survive on these supplemented plant-based diets? Yes, many of them do
Do cats thrive on these diets? No, they do not.
Please pay special attention to the words *survive* versus *thrive* as there is a very big difference between the two states of health.
Another important issue with regard to the protein contained in a dry food is that it has been cooked at very high temperatures for a long period of time. This extensive cooking required to dry the product significantly decreases the biological value of the protein sources.
With regard to the overall protein amounts contained in a food, do not be confused by the listing of the protein percentages in dry food compared to canned food. At first glance, it might appear that the dry food has a higher amount of protein than the canned food—but this is not true on a dry matter basis which is the accurate way to compare the two foods. Most canned foods, when figured on a dry matter basis, have more protein than dry food. And remember, even if this were not the case, the percentage numbers do not tell the whole story. It is the protein’s biological value that is critical.
above information taken from http://www.catinfo.org/index.htm#Cats_Need_Animal-Based_Protein_
Lisa A. Pierson DVM
Information on this site is for general informational purposes only and is provided without warranty or guarantee of any kind. This site is not intended to replace professional advice from your own veterinarian and nothing on this site is intended as a medical diagnosis or treatment. Any questions about your animal's health should be directed to your veterinarian.