(As appeared in the Canine Gazzette Newsletter Jan 1997)

In the past 10 years there has been much research in the use of both soybean meal and animal fat, as sources of adding protein to the canine diet. Along with the research, there has been much controversy about which source provides better protein without too many side effects. Many advertisements will promote their dog food product by claiming that their food contains one type over the other in an attempt to optimize their ingredients and minimize the effectiveness of the other.

The bottom line to all the research has shown that both soybean and animal fat are excellent sources of protein, in fact recent studies have shown that because soy protein provides very high levels of quality amino acids, it is an excellent source of most amino acids. In most dog foods available today, soy protein is combined with other sources of protein in a complementary way to provide dogs with high quality, easy digestible dietary protein.

Animal protein on the other hand will show great deviations in the quality of amino acids, depending on the source that it was derived from. The poorer the quality of meats or animal by-products used, the lower the grade of amino acid that it will provide, thus making these sources not as digestible as those from higher grades of animal meats. Protein derived from chicken is considered to be more useful to the dog digestion than protein derived from red meat, likewise fish-derived protein was by far the more digestible of the animal based proteins, thus utilized more by the dog's digestive system. It is evident that the source of the protein becomes very important when considering its' value for the canine diet.

Some other concerns that have been addressed recently with the newer studies have been whether soy causes more allergies and also whether there is a higher rate of "bloat" in dogs feeding on soy based diets. In the past, critics of soy protein had contended that soy protein was a potential cause of bloat, since soy based diets sometimes cause flatulence or gas, in dogs.

Bloat most often occurs in the medium to large breeds and can be a potentially fatal disease. The conditions causes abnormal swelling of the stomach, distending its' size and thus compressing other vital organs and constricting arteries and blood vessels.

The College of Veterinary Medicine at Cornell reported that there was no evidence that supported the claims that soy protein contributed to bloat. Their research concluded that dogs consuming meat-based diets were just as likely to develop the condition leading to bloat as dogs consuming soy-based diets.

Further research into the causes of bloat have shown that dogs that are fast eaters, scarfing their food too rapidly and then consuming great quantities of water were more likely to develop bloat, regardless of the source of food they consumed. Some researchers also have demonstrated that the gas associated with bloat was actually swallowed air and not gas caused by the fermentation of soy or other proteins and foodstuffs.

Another area that was explored by researchers was the claims about whether certain sources of protein caused more allergies than others. Surprisingly the largest percentage of allergies was not food related at all, but rather, most stemmed from respiratory allergens. Air pollutants, pollen, dust and flea-related allergies comprised the largest percentages seen in most of the research work. Food allergies were minimal in comparison to the vast numbers attributed to the aforementioned. Although reactions to proteins can occur, they are rather rare and dietary trials must be performed to isolate the suspected allergens

In conclusion; all the newest research indicates that there is no single perfect source of protein, however, what is important is that quality of the source plays a very important role. Most sources of protein can actually be used together to complement each other, with the amino acids that are deficient in one might be present in the other.