I know that dogs sometimes get flea drops, which gets in their blood and hence makes their fur poisonous for chicks. I hope horses don’t take medications that can remain in their fur?

That’s interesting, thanks for sharing!

Yes, according to vets and avian specialists, they pose a significant danger for birds. Personally, i wouldn’t risk it. Birds are very sensitive to polluted air, way more than humans are.

However, if you have pet birds and you would light a scented candle, or burn a non stick pot, these poisonous substances will affect them so much harder than for humans, often with deadly consequences