That statistic has been debunked many times. It assumes that cattle are raised specifically for dogfood, which just isn’t true. Dogfood is made from beef (and other meat) by-products that are not suitable for human consumption. It’s nearly all surplus protein that would otherwise be thrown away.
Living on Vancouver Island salmon, trout, and other seafood are quite readily available to supplement our pet’s diets. The occasional rabbit, bird, or squirrel also helps out. They prefer things like “The Farmer’s Dog” and other pet food found in the refrigerated section of the pet store. And I will also an extra burger or chicken or two for the pack.