You have basically just stated the equivalent that Arsenic will not kill people because it is in the food we eat (and it is).
Correct to some degree, like all things it comes down to the amount of exposure. We have all been exposed to Roxarsone but we aren't dropping dead from consuming chicken; we have all been exposed to cigarette smoke either directly or second hand yet we won't all die from it.
Sorry, man. Pyrethrin can be deadly to any pet in a relatively small dose (though not always of course)
Here's an opportunity to better educate me, define or better yet quantify what a "relatively small dose" is.
Lets look at the oral LD50 of a 1% pyrethrin based product, for a male rat you are talking about 2140mg/kg, conversely (and I apologize this isn't quite apples to apples but you get the idea) the LD50 from the venom of a Honey bee on mice is 2.8 mg/kg... I'll take my chances with the pyrethrin.
Do you have any experience with treating Pyrethretic animals???
No I do not, nor did I ever encourage anyone to sprinkle some pyrethrin on their pets food and I am sure your wife has seen animals who became sick from exposure to a lawn application but I am willing to bet the amount of animals she has seen versus the amount of animals exposed to pyrethrin is very, very small. I doubt anyone else besides you and I really care about this side topic so if you want to get into a much more detailed discussion, shoot me a PM, I think you'll be surprised at just how much I know about certain insectides
For those who are concerned about using a "pesticide" on their hops, have a look into Diatomaceous Earth, not quite as effective but I doubt there is any argument regarding its safety.
Sorry for the unintended hijack.