All-Wise,
You can do your medical in any of the DMP on CIC approved list. In other words, you can do it in Dubia. Just print out the medical forms and with your International passport you are good if its e-medical the DMP is operating otherwise, you will need passport photographs. However, you should also be mindful of the fact that you must have been given a time frame for the Visa office to receive all the documents they have requested from you which in most cases is 60days, so you will also need to plan how to ensure Accra receives the updated forms, PCC, RPRF etc on schedule. Hope this helps, enjoy your vacation and best of luck.
Ikemba