Originally Posted by Melcakes  Well here are some things I've across that looks at the "perhaps myths (as they like to call them)" about raw diets or should I saw what raw feeders believe. Some of it is interesting, but I've also read a lot of other things and some additional studies that make you also question what I'm about to post below.
1. Evolution Divergence from Wolves - Some studies that go the "Other Way"
"Robert Wayne PhD, geneticist at the University of California at Los Angeles examined DNA in dogs and wolves. Wayne's recent genetic work suggests dog ancestors of some sort broke away from wolves about 100,000 years ago. Wayne's work included 147 dogs representing 67 breeds and 162 wild canids of all species from around the world. Wolf and human remains have been discovered in early fossils from over 400,000 years ago, but dog and human fossils date back only 14,000 years. Prior to this study, domestic dogs were thought to have originated only 14,000 years ago. In this new study, Wayne and his associates studied patterns in the mitochondrial DNA from dogs, wolves, coyotes and jackals. This type of maternally passed DNA changes at a specific rate. Wayne's study showed so many DNA changes that dogs must have diverged genetically from wolves about 100,000 years ago.
"We expected to find DNA sequences in dogs that were closely related to those in wolves, perhaps even indistinguishable from those in wolves," Wayne said. "We expected to find a few different sequences in dogs; instead, we found 26."
The researchers found four distinct genetic groups in the dog world. This suggests that dog ancestors domesticated several times within the +100,000 year window, or at different places, and that no single wolf ancestor is common to all dogs.
In a similar study conducted by Vila and Maldonado at the Department of Evolutionary Biology, Uppsala University in Sweden, maternal DNA showed a separation of 135,000 years between modern domestic dogs and wolves."
Not sure how true this is but from additional readings and an article:
"One of many good examples of internal changes that natural selection wrought is a significant difference in the eye of modern wolves and modern domestic dogs. The topographical distribution of retinal ganglion cells in seven breeds of dog (Canis lupus f. familiaris) and in the wolf (Canis lupus) was studied (Can't find the study online - need to look more ). A prominent feature of wolf retinae was a pronounced "visual streak" of high ganglion cell density. By contrast, a moderate visual streak was found in dog retinae. The estimated total number of ganglion cells averaged about 200,000 cells in the wolf and 115,000 in the dog.10 Evolutionary natural selection reduced the domestic dogs eyesight to almost half that of the wolf. Yet raw feeders would have you believe there are neither biological nor physiological differences between the two. Still not convinced this alone affects how a wolves and dogs nutrionial needs would differ. Seems a bit irrelevant to nutrition, but does show biological/physiological differences.
Further evidence of evolutionary changes in the dog compared to the wolf abounds in the literature. In a study of 2,959 dogs across 40 different breeds Genetic mtDNA variations in domestic dogs show a much higher level of heterozygosity when compared to wolves. (Can't find this study online, just an article) Differences in musculature, tendon strength, gut wall arterials and many other distinct differences in the internal organs and abilities are described.
2. Increased BUN levels in dogs fed raw.
"A large study conducted by Dr. Joe Bartges, Dr. Jean Dodds and Dr. Susan Wynn, they looked at blood work from over 200 raw fed dogs, and compared it to 75 dogs eating 'normal' diets and used by the lab for reference values. Mean BUN (blood urea nitrogen) was indeed significantly higher in dogs eating the raw diet. Increased BUN is one of the most critical values examined when looking for renal failure. While it is incorrect to state that increased BUN might cause renal failure, it certainly is a significant warning of impending danger in older geriatric dogs with undetected renal failure."
Just little, but of course interesting little tidbits of information since you want to look at "both sides". Will post more later. |