It acts as a meat substitute, binding the kibble together, and artificially increasing the protein content of the food. (acupetvetcare.com)
When I made this, I also increased the protein content by using a high protein, fat - free milk mixed with lemon juice rather than using buttermilk. (staceymattinson.com)
Dried egg product is generally a good ingredient but it is difficult to see why pea protein would be included except to increase the protein content without adding more meat. (pawster.com)