I was advised by a professional to include animal protein in larger than moderate amounts (low carb). is that safe after a decade of veganism? thanks

Safe, yes: This may be recommended because you have a deficiency of some sort. However, like anything we do to our bodies, try to give it time to adjust by making the transition slowly instead of overnight. Hydrate well also.

Maybe: Have you spoken with a physician or a nutritionist? The only reason to ingest animals would be a vitamin b deficiency. I would be very hesitant to tell you to eat animals. It may give you diarrhea but there aremany reasons to avoid meat. High amounts of protein can harm the kidneys and animals can cause weight gain, cholsterol elevations, heart disease and more.