It is very common for Huskies to simply never become 'cat-safe' dogs even with dedicated training. They are dogs with a high prey drive. Cats also have this bad habit of just gawking at dogs with those huge eyes of theirs, which can very easily be seen as a challenge to the dog. I wouldn't say that there is anything out of the ordinary or wrong with your dog; a lot of dogs would kill a cat if they had the chance. Difference being that Huskies are very fast, athletic and poised creatures. So if/when they do go for the cat, its a lot less likely that the cat will simply escape unscathed.