Your little one sounds amazing, what an amazing job you're doing raising him
In all honesty, kids can be mean and it's just a part of life. I suffered badly at the hands of bullies in primary school for being vegetarian. It is probably best to limit the impact by explaining to your child in what ways other kids may be mean about being vegetarian/vegan and why they do it. It does make it easier to deal with at the time and makes it easier to rise above any bullying.
By high school I had no issues really, the odd comment but I never fought back so it ended there.
At the end of the day people are generally just looking for a reaction, best thing I would say you could tell your child in regards to bullying is ignore it. They always stop when you don't give them fuel to go on.
