I absolutely an emphatically agree with the message here. Traditional antifreeze (ethelyn glycol) is not only toxic but also very tasty to pets. It’s exetremely important not to leave spills of this stuff lying around, and especially not to leave jugs or pans of it lying around, like if you’d drained it in preparation for refilling it with fresh.
I will add, however, to be sure that whatever you use is correct for your particular vehicle. There are different methods by which antifreezes protect engines, and you don;t want to use the wrong stuff. I’m not personally familiar with Sierra, but it’s worth looking into. If you have any doubt, talk to your dealer.