Do you mean a stroller, in which the baby is pushed around? Or do you mean a walker which supports a baby while he learns to walk?
Walkers are not sold in Canada because they are dangerous.
My nephew has a long scar on his chin from a fall caused by one of these. He needed five stitches which is a lot on a year old child.
Today it is covered by his beard, since he is over 40. The walkers were banned about a decade after his accident.
So no. It would be seized at the border and not returned to the seller.