TubeNet

Typically, the Canadian University system employs non-tenured instructors on (in this case) tuba/euph. Not all the schools are the same, but it is not as common as in the US. Typically, the guy in the orchestra teaches at the University or Conservatory with a few exceptions (as always). For example:
Montreal (McGill): Dennis Miller
Toronto: Mark Tetreault, Sal Fratia
Vancouver: Ellis Wean
Quebec: Lance Nagels
Calgary: Mike Eastep

If there are any jobs, you may find them here:

https://www.securewebexchange.com/oc.ca/index_eng.php" target="_blank" target="_blank
http://www.universityaffairs.ca/" target="_blank" target="_blank

Cheers,
DK

One thing to be aware of is that unless you are a Canadian citizen or a Landed Immigrant, you will be at a distinct disadvantage applying for a college or auditioning for an orchestra or band position. (In the case of the military and RCMP bands, Canadian citizenship is a requirement.)

Canadian law REQUIRES employers to give preference to Canadian citizens and landed immigrants. While it is not impossible for a non-permanent resident to gain employment in a Canadian university, orchestra, or band, the prospective employer must still show that:

it cannot find a suitable Canadian or permanent resident to fill the position;
bringing the prospective employee to Canada will not have a negative impact on the Canadian labour market; and
the prospective employee meets all other requirements and conditions, including immigration and health care eligibility requirements,

before a work visa will be issued.

Pgym