Hi Izzie and welcome to you from Lancashire,England all the way to you in Beautiful switzerland
Whiska's for us is not a good choice as imo it's full of rubbish and will only make a dodgy tummy worse as it's also very rich,can you get and maybe try minced meats.ie chicken,beef,turkey,lamb etc as sometimes here it works out just cheap if not cheaper than any brand foods and again imo much better for them
Can i ask what breed if any your cats are and do you have any pics to share with us plz