I've just lokoed at the RSPCA site and two things make me deeply suspicious: first the dog doesn't look like it's very distressed by having a hook through its nose. The person holding its head is using a very gentle grip. Second, if you want to catch a shark, the hook has to end up in its mouth, which doesn't seem likely with the hook placed so on the dog (a medium-sized mongrel, from the picture; far more likely that the shark will pull the dog clean off the hook at first bite-and-thrash. To be honest, dead, bloody dog chunks would be better bait than a whole beast, and easier to manage on board a boat.