Somehow I just don't doubt pet food companies would do something like that. Salt is addictive. I have read several articles on the subject. You aren't necessarily aware of it but it is. There is no excuse for the amount of salt in our food or pet food. Take a plain bagel one large plain bagel has 700mg of salt! Raisin Bran, Kellogg, 1 cup - 362, Cottage cheese, fat free, 4 oz - 380, two tablespoons of zesty Italian salad dressing Italian, zesty - 510.
Now go look at pet food labels. I just checked out the Marshalls ferret food. The label states salt but not how much.
I do know that MANY ferrets have died of salt poisoning from human snack food, chips ect. Here is the first part of my complete series on ferrets
Ferrets I also have a paperback book published (also Kindle) Ferrets: A Complete Guide. It can be found on Amazon.