Best herbivorous pets?

One of the things barring me from committing to veganism is wanting pets. Despite the many choices for a pet, cats and dogs remain the best choices. One is their ubiquity and the second the long amount of time humans have been with them. Them being mammals also means that their brains are more developed which makes them more interesting to be around and they also form social bonds.

A thought I've had is that if I'm a vegan but I acquire a pet that's not, that I'm still contributing to the needless slaughter of industrial farming.

I don't hate carnivorous animals that's just the way they evolved. Humans aren't and we have a choice to not be carnivorous.

I've looked into small fish because I like watching them swim around. Tortoises seem like a good option but they're not mammals. I've thought've pigeons because they're smart, social and herbivorous. I've thought of rabbits but apparently rabbits can die of being scared so maybe not. A pygmy goat seems like a good option too. Maybe a pygmy pig?