Thank you both for replying to my question.
Leon, you asked where I found the info I stated earlier:
Applicants may be denied a Canada Immigration (Permanent Resident) Visa solely on medical grounds, if:
Their condition would endanger the health or safety of the Canadian population at large; or
Their admission might cause excessive demand on existing social or health services provided by the government. *
When determining whether any person is inadmissible on medical grounds, the medical officer is obliged to consider the nature, severity or probable duration of any health impairment from which the person is suffering as well as other factors, such as:
Danger of contagion;
Unpredictable or unusual behaviour that may create a danger to public safety; and
The supply of social or health services that the person may require in Canada and whether the use of such services will deprive Canadian nationals of these services.
* The excessive demand component is waived under the Family Sponsorship category of Canada immigration for the spouse, common-law partner, conjugal partner and dependent children of the Sponsor. The Sponsored person(s) still may be refused if their condition is considered to be a danger to Canadian public health or safety.
http://www.canadavisa.com/immigration-medical-inadmissibility.html