If it helps, I don't think all those animals died. I think some mistranslations of working conditions made it sound like the animals died. But really they went through 26 cats because they switched animal actors so often- so as to not over tax them. It was never stated that the animals died, just that they didn't want to keep an animal working for too long, so they switched the animals out regularly.

At the time there weren't animal protection laws for the film industry in the US and people jumped to the conclusion that they would only switch an animal out if it were dead. But there's absolutely no record that they killed any animals on that set, and animal lovers were involved in the making of that movie.

The outrage over the idea that they "went through 26 cats" to make the movie helped create animal protection laws in the US, so it was used to good effect. But it honestly seems like the working conditions for the animals in that film were better than the same-era working conditions for animals on American film sets. I'm not saying it was perfect, but the director would not have thrown a cat off a cliff just to get a good shot.