Basically, in the UK, the rat submerged in the oxygenated liquid scene breaks the law in regard to cruelty to animals on screen.
Disney asked for guidance about this last year and the BBFC said the film would have to be resubmitted for cuts as the law still stands. The film has not been resubmitted, so I guess Disney just cancelled the UK release.
I’m waiting to see where I can import from the cheapest…
The rat survives, all of them did as you say. It’s been a very long time, but I believe in the documentary, Cameron says there were vets on set to care for the animals.
The problem with UK law can be seen in this quote from the article,
As you can see, here in the UK, the fact the animal survived doesn’t matter, it’s the fact it was put into distress for the purposes of making the film.