There are lists of what is safe and what isn't. I don't look at the lists. I have a plant I know is p poison that grows in their run and they don't eat it.
I believe tomato plants may be on the dangerous list, but mine live tomatoes! I think they eat them green, red or rotten. I also think mine leave the plants alone.
Mine eat small quantities of things I think are on the no list, but after 4 years, who am I to stop them. It seems to be more an issue of eating too much of certain things that cause the problems. It shouldn't be their only food. Cabbage is an example of a treat that can be harmful if overdone, I believe. Fine as a treat, not good as a primary dirt