True there were other products in the same section that were not labeled for use in poultry. The place where I bought mine (90 minutes from home), this was the only pump spray one they had... and it was in the horse section. Also my LFS only carries it in their equine section and nothing like it for chickens in the chicken section. My closest TSC is like 6 hours away.
And it happens to have a picture of a chicken on the label. All others required me to have another sprayer, so this is what I went with and for $8 and lasting me 2 years with 82+ birds, 2 large goats, and 3 med/large dogs no guessing if my measuring or calculating skills for dosage is correct.. it was worth my time and $ to not have to store yet one more item I don't have room for or won't be able to find when I need it. I do believe it's also labeled for use on the walls and such.
Guess I didn't think of other ingredients not being chicken acceptable if they were just inert and not active. But that's a good point. Thanks for bringing it to my attention.