**The problem with poison grains is that the critter will pack its
cheeks with it and travel on.
Gophers can go 500' from the source of the grain.

I had an acquaintance lose his Borzoi a couple of months ago from eating
a gopher whose cheeks were packed with the poison. (The autopsy showed
the grains in the dog's stomach, and they checked with neighbors
surrounding their 2 acre parcel. Unfortunately their neighbor had been
baiting. Once the dog starts seizing their not much anyone can do.)
The normal poisoned gopher probably wouldn't kill a large dog except if
he was storing the grain in the cheek pouches.
Gracie was picking off a couple of gophers a day in the spring and we
were just hoping we weren't close to anyone using poison for control.

Having animals keeps us honest about using pesticides and poison.
I had 3 Basenjis climb a 6 foot ladder to get at an unopened box of
Corry's Snail bait.
They ate enough to kill them, so off to the vet they went.
The vet said that most snail baits taste like licorice so they're very
appealing to dogs.
The poison rodent grains are probably equally tasty.