Here's how it happened
15,000 years ago

Human interaction led to eating leftover scraps of meat, bones & organs.
1860

The first dog cakes were made from leftover sailor biscuits in the shipyard.
1920s

Technology to preserve food changed everything. Horse meat was the main ingr.
1940-50s

Made from the same process as puffed cereal (extrusion), kibble was born.