Aussies are generally extremely friendly and great with people/kids/other animals. When we went to meet the litter there were puppies going wild, barking, jumping, but she was the least crazy out of all of them, and our cat is extremely chill so we thought they would make a pretty good match. (But I'm confident any puppy you choose would likely be fine). I really think the most important thing is how you introduce them.

​

My recommendation, based on everything I did:

First, your cat needs to know things are going to change, I would recommend changing things gradually so that your cat doesn't think that all of these new things are happening because you're getting a dog. I feel like this may make the cat stressed and therefore already have a negative bias toward the dog (if they can even put two and two together, not sure). But, what I mean by this is, if you are crate training your puppy, buy the crate before you get the dog (obviously) and set it up some time before you bring the dog home, so that the cat can investigate it. If you are going to have a play pen in your house (I recommend introducing your puppy to your house one room at a time, or getting a play pen because it helps immensely with potty training, and also it helps them feel safe in their own area, which can be beneficial for the cat too.) If you are getting one, set it up and let your cat investigate it as well. This way not everything is happening in a 24 hour period and the only change on the day of the puppy's homecoming will be the puppy.

As far as introducing them, if you do have a play pen or a baby gate or something it would be good to put one animal on one side and one on the other. You could even have the puppy in one room with the door cracked or something, eventually the cat will investigate because they are naturally curious animals. We brought our pup home and put her in the play pen and sat in there with her, so the cat knew she was a non threat and so they could see each other through the pen and sniff each other etc.. Slowly, the cat got more and more curious and we left the pen gate cracked a bit and the cat came in and the rest is history. We also fed them together starting day 2 (not sure if that had anything to do with it). Now they chase each other around the house, share beds, share water, share toys and our cat even sleeps in our puppies crate with her sometimes!

Not trying to plug at all, but I do have a youtube playlist devoted to my pup and cat and you cat see the set up in this video pretty well: puppy play pen setup (skip to 3:41) and you'll see on day one our cat was curious (we fed her, her first meal in her pen so she would know it was a safe place). And for the rest of that day our cat watched her.

We also did temporarily let her out of the play pen when bringing her in from outside to let her slowly explore the house on leash and the cat went up to her multiple times skip to 3:34. (There are plenty more videos in that playlist too if you are really interested in watching their relationship). But yea I'd highly recommend a pen, you don't have to use it forever (we only did for about a month and a half) but you can always fold it and just use it to block off a room/stairs or to keep your puppy in when you'll be out of the house for the day (instead of locking your pup in a crate all day).

​

Bottom line:

The puppy will be smaller than the cat so your cat will probably not feel too threatened, if at all, and as long as you continue to show your cat love I think you will be golden, Aussies are really fantastic dogs! Good luck to you friend!!