pnuts did give you the link in comments, but to expand further, from cic.gc.ca:
A single entry visa allows you to come to Canada only one time. Once you have left Canada, excluding travel to the United States and St. Pierre and Miquelon, you will need a new visa to travel back to and enter Canada.
and
A multiple entry visa allows visitors to come and go from Canada for six months at a time, without having to reapply each time. It can be valid for up to 10 years, or one month before your passport expires, whichever is earlier. You must arrive in Canada on or before the expiry date on your visa.
Specifically to your question:
If your visa is still valid and you are travelling only and directly to the United States (including its Territories and Possessions) or St. Pierre and Miquelon, you do not need a new visitor visa to return to Canada.
So US, St. Pierre and Miquelon are fine – no impact on your visa. All other countries either require a new visa (if you are on single visit) or have no impact (if you are on a multiple entry visa).
Note that since February 2014, Canada does not seem to issue single-entry visa any more, so visiting any country should not joepardize the duration you are allowed to stay in Canada:
Starting on February 6, 2014 (00:01 EST), all visa applicants will automatically be considered for a multiple entry visa.
Credit:stackoverflow.com‘
5 Mar, 2024
5 Mar, 2024
4 Mar, 2024