are pyrethrins toxic to cats
Most pyrethrin poisoning happens when a well-meaning owner uses too much of a pyrethrin-based product or uses one that is too strong for a cat. Kittens, elderly cats and underweight cats are even more susceptible to pyrethrin toxicity. This is because their bodies can't process the chemical as well, and the lack of a protective layer of fat allows the chemical to soak right into muscles and tissues.