Objection to commercial pet food
There are numerous arguments over the health effects of feeding commercial pet foods, and many raw feeding pet owners claim to have noticed a significant increase in overall health after switching to a raw food diet.
Because commercial pet foods are assumed to be the primary or exclusive element of a pet's diet, manufacturers enrich their product by supplementing the food with vitamins and mineral. As the heat used to process commercial pet foods may reduce the level of naturally occurring nutrients, critics question the actual nutritional value of commercial foods. Critics argue that there may be elements to pet nutrition are yet to be discovered or well recognized enough to be supplemented. There is also skepticism over the efficacy of supplements vs the natural absorption of naturally occurring nutrients. The same rationale is used by some to reject supplemented home cooked pet food. A study involving rats has suggested that the digestibility of the amino acids in cat food is altered during heat processing.
Commercial pet foods, dry foods in particular, often contain a large amount of grains, which proponents of grain-free food feel are inappropriate for dogs and cats. Because cats are obligate carnivores, it is believed that a switch to a predominantly meat based raw diet would be especially beneficial (as compared to a raw diet for dogs) due to cats' relative inability to digest grains. Studies comparing the source of protein in dry cat food concluded that the digestibility of meat-based protein is superior to corn-based protein.
Veterinary surgeon and raw feeding proponent Tom Lonsdale states that food from dry or canned commercial kibble sticks to teeth and enables bacteria to proliferate, causing "sore gums, bad breath and bacterial poisons that affect the rest of the body". Lonsdale further states that dogs lack the necessary enzymes to digest grains and plant material and claims that grains cooked at high temperature can cause starch, proteins and fats to become "denatured or toxic in variable degrees." The poorly digested grain is said to support toxin-producing bacteria in the lower bowel which may eventually lead to "poisons pass[ing] through the bowel wall into blood circulation" creating further problems in other organs.
Source - Wikipedia
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