I am less worried about actual income problems as to medical needs, even with required medical tests. CPP and OAS would generally not apply to this group.

From: http://www.cic.gc.ca/english/immigrate/sponsor/pgp-apply-who.asp
"When you sponsor a parent or grandparent to become a permanent resident of Canada, you must promise to support that person and their dependants financially. Therefore, you have to meet certain income requirements. If you have previously sponsored relatives who later turned to the Canadian government for financial assistance, you may not be allowed to sponsor another person."