I put Seargents flea stuff on my chihuahuas and they both got very sick for days. It is also odd they both got infested with ticks 5 days later. They had no ticks prior to putting this crap on. It was like it attracted them. I bought a Bayer brand soap to kill the ticks and get them off. I will never use this cheap Sargeants stuff again. I normally switch from Advantage and Frontline but I did not have any and thought I would try the cheap stuff. Never again!!! You get what you pay for.