While you may see "veterinarian recommended" printed on pet products, my experience has been that vets don't generally recommend pet products that they don't sell in their practices. Except for Feline Greenies.
Making money off of your pets seems somewhat counter-intuitive. Don't we adopt pets to be our companions? Yet 'stage moms' like Gypsy Rose Lee and the term 'momager' first introduced by Kris Jenner who promotes her brood of Kardashians have been cashing in on their progeny for quite some time now.