Zoomanaic the Canadian hippos cannot breed for a number of reasons. Yes there is the genetic component with so many being related. There are definitely Canadian options. Samson from Toronto could move to any other zoo and breed with any female. That zoos male could easily come to Toronto and breed with Petal and Perky. And there could be swaps with US zoos for sure.
Bigger problem is that no Canadian hippo has enough of a known lineage to make the SSP consider them breedable. Sure Canadian zoos could just ignore the ssp and breed but then the SSP has the right to say no when it comes to finding new homes for the calves. That's the big problem. Where will unwanted calves with questionable genetics go? Canada only has so much space and US zoos would rather house hippos that they themselves can breed in the future. All those new facilities in the US want breeding pairs so that they can cash in on adorable calves and recoup some of the massive expenses associated with building a state of the art hippo exhibit.
In the end unless more space is built in Canada... I think Toronto is the only one with a hippo exhibit reno in consideration in the next 20 years... breeding the current stock is unwise. Seeing as Toronto's crew is the oldest, Toronto stands the best shot at having breeding stock in the future. If the reno that is planned long down the line happens it is very likely Samson will not be alive and a breeding pair can be brought it. If Petal and Perky are still around they could live with the female and calf.
@TZFan: Thank you for your reply and your explanations.
Just one question: What about importing hippos from European Zoos for Canada? Afaik there are also many individuals in our continent with unknown origin. Or is there a problem with SSP/ESB regulations respectively? (There is no EEP for hippos afaik)?
Canadian zoos could perhaps deal with European zoos. Import export could prove tricky and costly though. Toronto just imported a pygmy hippo and that was in works for well over a year that I know of. Plus Toronto and Calgary are probably the only two who could seriously afford importing or exporting hippos. It'll probably be easier to wait out the current stock and replacing with AZA animals down the line.