Thank you for your question. It appears to be scab, which you can read about here: https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-scab However, this is based on a Pacific Northwest diagnostic tool, which may not be applicable to your region. Although it has chemical treatment suggestions, they may not be available in Canada. I would suggest that you contact the Toronto Master Gardener association for recommendations: https://www.torontomastergardeners.ca/ Good luck!