Just a few useless stats and stuff :

Commercial dog food has only been around for about 100 years, how long has the modern dog been around for? Pekes have been around since 2000BC.

An american had the idea for it on a voyage to Great Britain. When he came off his ship docked in England, his attention was caught by the sight of dogs scavenging for discarded ships' biscuits on the quayside. (One question is were these dogs owned and cared for or were they stray dogs?)

James Spratt saw the need for specially prepared food for animals and turned his efforts to the production of dog biscuits. As far as I know these were based on ships biscuits.

And so the prepared pet food industry was born. Later, American companies like Mars produced canned food for dogs, followed on a commercial scale by Chappel Brothers in the United Kingdom who began canning a meat and cereal dog food.

Chappie dog food in 1935 was bought by Mars, 1954 - Pal launched in the UK, 1960 Chum is launched in the UK, 1964 - Chum dog food is renamed Pedigree Chum and begins its long standing relationship with the Crufts Dog Show in the UK. Silbury Soames is the first dog fed on Pedigree Chum to win the Best in Show award. 1980's saw Cesar dog food and Frolic. 2000+ Mars buys Royal Canin, Doane Pet Care (US dry food manufacturers) & Neutro Natural pet foods. (Mars timeline)

Extract from F.E.D.I.A.F. NUTRITIONAL GUIDELINES FOR COMPLETE AND COMPLEMENTARY PET FOOD FOR CATS AND DOGS (p53)
"There are proteins against which dogs and cats seem to react more often (Wills ‘94). Milk, beef, eggs, cereals and dairy products are mentioned most often whereas more controlled studies mentioned wheat, soy, chicken and maize as the most important allergens. However, it is not always clear whether these data are taken over from human literature or not. In addition, the data does not always enable us to see whether the high incidence is not simply the consequence of the fact that those proteins have been eaten more frequently by cats and dogs."