Do any of the Canadian provinces require that you offer continuation of health coverage to terminated employees, employees going on long-term disability, etc. similar to the COBRA requirements in the U.S.? If so, do you know where I can learn more?

No there isn't anything similar to COBRA in Canada.

I will point out though that if the employer terminates the employee in some provinces such as Ontario there maybe the requirement to continue benefits. OFten the employer value of the benefits for the severance period is paid out in cash as part of the severance. Its typical in Canada for severances to also include an additional amount equal to teh employuer paid value of the company provuided benfits ffor the length of the severance period.