Some mals do really well with cats - especially if they grow up from puppyhood with them. Some mals do not ever do well with cats and have been known to easily kill them. That is the worst-case scenario though and everything in between. I would ask your breeder for sure or even try to get a pup from a breeder who has small animals as you would have a better chance that way. It is the prey instinct that they can have - out of the blue - for a small fast-moving animal. They do not intend to be bad or go after small animals but it is in their 'genetic' makeup so to speak. Mals left alone - especially if there is only 1 - they can get into trouble really fast. I would recommend getting with a good breeder and making sure you understand all the precautions - they can be famous furious diggers, leap fences in a single bound, etc. If they are bored or feel alone, that's when you can have some "not" fun. We leave one of ours alone for a few hours in the backyard but we will not leave our young male at all by himself - just as a precaution as we want him to be there when we get home! Every dog is different though and again, it has a lot to do with breeding and then training them as pups or if more mature, it can take longer to break bad habits if anything has been done with them that isn't quite right for malamutes.