My ferret recently had surgery due to stones in his bladder. My vet says the stones were caused by his diet, and he's seen this case before with other ferrets on the same diet. I have been feeding them ZuPreem grain free since I brought them home about a year ago. I am looking into a raw diet for them but there isn't much information online and my vet says it's not ideal as it is hard to give them the right amount of nutrients. He suggested a high quality cat food but everywhere i look online says to never feed ferrets cat food. I am not sure what to get them at this point... I like the idea of Wysong as it has been recommended many times on a lot of ferret sites but the only store in town that sells this brand only has the dog/cat foods. Would a cat version of Wysong work? Or any other diets you would highly recommend for my ferts?

I have my kids on the natural variety products.  No grain cat food and commercial raw products.  

I hope this helps

If you are interested in feeding raw.  I suggest visiting the holistic ferret forum.  They can help you out on a raw diet.

http://holisticferret60.proboards.com/

There has been a lot of theorizing about peas and other legumes in ferret kibble causing stones.  Evo and Zup grain fre both had them at one time (Evo still does) but I believer they have been removed from the Zup grain free.

I checked, and the peas have been replaced with sweet potatoes.  

http://www.zupreem.com/products/grain-free-ferret-diet

You might want to research calcium oxalate content of kibble ingredients.  I did just that a couple months ago, but all of the articles I found were about humans.

http://forum.ferret.com/tm.aspx?m=245248 

THE DOOKS OF HAZARD

I know the last response was approximately 11 days ago, but I thought I'd give you my two cents about the cat food.

I have no experience with raw feeding (My ferrets do get some raw meat every now and then when I'm cooking), but I have been feeding my 3 ferrets cat food for the past few years. Personally, I have had terrible experiences feeding them ferret food that you find in pet stores. Ramsey had many upset stomachs and unhealthy looking stool, but it all went away when I switched them to cat food. I prefer cat food because they are both obligate carnivores and since cats have been around longer, you have more choices of highly developed kibble with more natural ingredients. Ramsey has been on cat food for almost 3 years now, and I haven't had any health issues with him that are diet related (He's never been a healthy boy because he was severely neglected as a kit, so he has a sensitive stomach). Yes, cats have a much longer digestive tract compared to ferrets, but personally, I haven't had any issues with this. In fact, they look healthier! Muscle, soft fur, and active! In addition, I do also believe that each animal is different to the diet you offer them... Some may do fine, while others may not. Might want to customize what works best for your pet.

I currently feed my ferrets Performatrin Ultra. Ramsey is at his peak with health at the moment, and so are my other ferrets. In the past, I have fed Orijen (Wonderful kibble!), Go! Natural Fit & Free, and Wellness Core. For ferret food, I've tried ZuPreem (Premium and grain free), 8-in-1 Ultimate Crunchy, and Living World (Probably the worst I've ever fed them. Didn't even finish the bag!). I stayed away from Marshall's food, period. Because Ramsey did suffer from helicobacter and a parasites in his intestines (Again, he came to me sick), I do feed my ferrets wet food on occasion. My vet recommends I give them wet food every now and then, because if they were to be sick again, it'd help with nutrition because it contains less sugar (However, higher in water content). I feed mine Wellness Core for wet food that they get at least once a month. Stay away from low quality cat food brands. 

I also found this link very helpful: http://forum.ferret.com/tm.aspx?m=245451

I might get a lot of hate for feeding my ferrets cat food AND wet food, but it has been recommended by my vet who specializes in small animals for almost 30 years and continues to do research. Not to mention, all of my ferrets are healthy (They just went in for their annuals) and that's all that matters to me!