Damned. I hate to see animals hurt. Sometimes when things are labled 'non-toxic, that means to humans. After all, chocolate, onions, grapes/rasins are POISONOUS to dogs, so only your vet or poison control would know. Does the product have a ph no listed on the packaging you could call? Cats are so sensitive to so many things, & god I love them dearly. I'm always having my heart ripped out over things cruel asswipes do to them. Should it turn out your ASS of a neighbor DID poison him, I'd exact some sweet revenge upon that sorry waste of space. (Provided he has no pets), An over dose of laxatives in the water supply would do just fine.
Keep us posted.