Fire crews were called to a farm in Middlesex Centre to deal with a large barn fire near Lucan on Thursday morning.
Crews from three separate fire halls were called to the scene shortly after 7 a.m.
By early afternoon the blaze was contained to the end of the barn where straw and hay were stored.
About 500 chickens and 65 pigs were reportedly in the barn when the fire broke out, but it's unclear how many animals have survived or how much damage there is to the structure.
There have been no reports of injuries.
