How do I know if my cat has eaten something toxic to them?

So that's hard because so many of the toxins can lead to different things, but I would say definitely monitor for his or her appetite level, his energy level, and any vomiting or diarrhea I would definitely take him into a veterinarian and see what's going on.

If the illness can be traced back to the addition of a new ingredient or food or something along those lines, that is when I would become suspicious. To answer one specific set of signs that can say, oh, that means your cat ate something bad, I can't do that because it just depends on what they ate. Certain foods can be toxic to an animal's gastrointestinal system. Some can be toxic to their heart and some can cause skin any issues. It just depends on what they ingest in order to be able to answer that.