On dogs yes, but you can overdose them.
It can kill cats that come into contact with treated dogs, via seizures.
Something about a cat's nervous system that makes them more sensitive to it.
Each person must decide for them if the juice is worth the squeeze in any given situation.
If I moved or was in a more tick infested area I might also use it, to.
Ticks and parasites in general aren't pleasant, and the viruses ticks carry are potentially very serious and sometimes, for some people life long.
I find it interesting that noone talks to much about the potential for negatives though, except that you should let it dry on your clothes before you wear them.