Newts are generally a safe pet, however there are a few species that are known to carry salmonella, and other species are in fact poisonous, but only if consumed. The brightly colored bellies of a newt are one way to tip a person off to their toxicity.ewts are generally a safe pet, however there are a few species that are known to carry salmonella, and other species are in fact poisonous, but only if consumed. The brightly colored bellies of a newt are one way to tip a person off to their toxicity.