Any kind of companionship, even a mouse, can provide that kind of emotional support, but that says nothing of the animal's intent or ability to harm others. They are solitary creatures whereas dogs are social creatures. It's little wonder they would be carriers for parasites such as Toxoplasma gondii, whereas dogs aren't

Cats are very much social creatures. They can share activities (or, more often, lack thereof) with others. But they're not pack creatures like dogs.