Obviously our dogs and cats' ancestors ate their food raw. Today with the introduction of prepared pet foods our dogs and cats eat cooked food. Commercially prepared pet foods are cooked to destroy harmful bacteria and parasites and to insure adequate shelf life. Does cooking however remove many nutrients that our pets maybe missing? Yes cooking also removes good things as well.
Many years ago Dr. Francis M. Pottenger, while working at his father's sanatorium for the treatment of human tuberculosis patients in Monrovia, California, conducted what became known as the Pottenger cat study. A large colony of cats were maintained and used to assess some of the foods that were fed to the sanatorium patients. While maintaining the colony he noted variations in some cats and decided to look into it with a study. This study, over a ten year period, on 900 cats looked at the differences in cats fed raw vs cooked meat. This series of controlled experiments showed some startling differences between cats fed raw meat and those fed cooked meat. Cats by their nature are strict carnivores and their ancestors like the dog ate their food raw.
The diet of all the cats consisted of meat; bones; organs such as liver, heart, brains, kidneys and pancreas; raw milk and cod liver oil. One group was given raw meat and the other cooked meat everything else was the same. The raw meat group, over the ten year study, were healthy, of uniform size, skeletal development and fur. Each litter averaged five kittens, miscarriages were rare and causes of death were usually due to old age.
In contrast the cooked meat group had no end of problems. Litter mates varied in size and skeletal structure. Common were vision problems, infections, arthritis, heart problems, inflammation of joints and nervous tissues, skin problems, allergies and intestinal parasites. Common causes of death in adults were pneumonia and lung abscesses while pneumonia and diarrhea were the common causes of death in kittens. Reproductive and behavior problems were also common in the cooked meat group.
This study conducted on 900 cats over a ten year period on the effects of cooked meat fed to cats may help to explain some of the health problems we encounter in our modern cats and dogs today. Today our commercially prepared pet foods are not only cooked - to remove contamination from harmful bacteria - but also use cereals and vegetable products in their formulations primarily for a source of energy and fiber. These ingredients are not only cheaper but require less attention to preserving and maintaining shelf life. Animal products: proteins and fats are much more expensive and must be processed to remove possible contaminants then preserved to maintain shelf life. Canned foods need only be processed with heat as the air tight cans then maintains the shelf life without the need for preservatives.
So why is pet food cooked today? Raw is obviously natural as the dogs and cats of old and in the wild didn't cook their food before they ate it. However their food was cleaner in that it was killed relatively recent and not exposed to too many other things by the time it was eaten. Pet food ingredients today have great opportunities for contaminations from many sources. Because of these opportunities for contamination cooking is important to kill harmful bacteria and parasites that may cause disease. However the good things are lost as well.
Pottenger's study showed that cats fed raw meat were healthier and more resistant to diseases and parasites. So in other words if the cat is on a totally natural diet it is better able to resist infection from disease causing organisms. Once we alter from the natural diet problems arise which leads to other solutions which in turn leads to other problems. For example a diet high in meat, which is low in calcium, must be supplemented with ingredients such as bone meal to balance the diet. Ancestral dogs and cats ate bones.
Some sort of processing is required for the vegetable and cereal ingredients much like the digestion undergone in the stomach and intestines of the captured prey. Cooking or some sort of processing of plant products makes digestion easier because some breakdown has been started. Cooking, as we have said before, does in fact remove and change some nutrients. We must then replace these lost nutrients after cooking. An example are the water soluble B vitamins.
The question then arises what is best cooked or raw? We are told fresh raw fruits and vegetables are best for us. Can we say that fresh raw meats are best for our carnivorous pets?
About Edmund R. Dorosz, BSA, DVM
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