If you let your cats outside, they may eat it. And it can make them
sick.
As my Vet told me, he has to work very fast on a cat that has eaten
snail
bailt lest the cat get well before  he can save it...

LT
.

It would depend entirely on which active ingredient is in the snail bait.
There are some that are "pet friendly" but that would still make an animal
sick at their stomach if they consumed enough of it. Sluggo contains iron
phosphate which is safe to use around pets.  I still wouldn't want them to
be eating it, as it definately could cause a tummy upset, but it won't kill
them.

There are a lot of solutions to slugs, such as a beer trap and laying down a
board that you turn over in the morning and then salt the accumulation off
into the trash.  Copper tape around a raised bed will also prevent slug
infiltration.  Keep a spray bottle of ammonia and water and go out at night
with a flashlight looking for slime trails.  Spray the intruder and watch
them do a Wicked Witch dissolving act.