Reddit mentions of Kirkland Signature Fllea & Tick Control for Cats

Don't buy their flea treatment. Fucking awful (I've never seen that many 1-star amazon reviews on any other product).

Their food is fantastic, though.

Hartz is absolutely terrible. I had a cat get very sick from it. That being said, Frontline is decent, but you can get it directly from the vet, and some pet stores. Obviously whatever the vet recommends I would go with.

My boyfriend picked up the Costco brand flea treatment (link is terrible reviews on Amazon) thinking it was the same as the Frontline without reading the package, and he treated the cats without me knowing, and its basically the same as Hartz or Bioguard. We had cats lose hair/get bald spots and get sick/flu-like symptoms and I got very angry with him. I had to wash it off of them.

He just assumed that because all other Kirkland products were good, that it was too. I never would have bought it after my experience with Hartz. I'd only trust something the vet gave me/recommended directly or Frontline.