Sim. Se você é concedido um visto de entrada única, você pode solicitar um visto de trânsito. Mas parece que você não precisaria, pois aparentemente há uma exceção que se aplica ao Estados Unidos :
Single entry visa
A single entry visa lets you travel to Canada only one time. For instance, you may only be eligible for a single entry visa if:
- you are eligible for a fee-exemption and the purpose of your entry to Canada is limited (such as, for an official visit by a foreign national)
- you are taking part in a one-time special event in Canada
- there are approved country-specific procedures or guidelines in place.
In most cases, once you have left Canada, you will need a new visa to enter Canada again.
You won’t need a new visitor visa to return to Canada if you are travelling directly to the United States (including its Territories and Possessions) or St. Pierre and Miquelon.