> the British Veterinary Association does not recommend giving a dog a vegetarian or a vegan diet

Imagine picking and misrepresenting what someone said. This is what British Veterinary Association said about vegan diet:
"advice is to always talk to your vet before changing any aspect of your pet’s diet"
https://www.bva.co.uk/news-and-blog/blog-article/is-it-safe-to-feed-my-dog-a-plant-based-diet-hold-the-greens-only-meals-why-the-jury-is-still-out-on-vegan-dog-diets/