Additional Links (Most links pertain to cats, but ferrets and cats have the same dietary needs so its relevant):
https://feline-nutrition.org/answers/answers-what-exactly-is-an-obligate-carnivore
https://feline-nutrition.org/health/crystals-raw-diets-and-water
https://feline-nutrition.org/health/diet-kidney-disease-and-the-urinary-tract
https://feline-nutrition.org/health/feline-cystitis-and-bladderkidney-stones
http://theferretzone.com/2011/09/14/keep-your-pet-ferrets-healthy-–-dont-feed-them-sugar/
By Holly
There are different types of bladder stones that are formed based on different conditions in the bladder - acidity being the main one. All bladder stones stem from the same things:
High magnesium/plant-based diet, Plant-based diet, peas, chickpeas, lentils, legumes, sweet potatoes, inbalanced urine pH
Symptoms: Difficulty/increased urinating, blood in urine, stinky urine, peeing in odd places, frequent licking genital area, lethargy, dehydrated, abdominal pain
Most ferrets will not be able to pass a bladder stone if it's big enough that you notice something is wrong. If a surgery is not performed, the bladder can rupture, which is life-threatening.
http://ferretbiology.com/Urolithiasis
https://www.petmd.com/ferret/conditions/urinary/c_ft_urolithiasis
https://vcahospitals.com/know-your-pet/bladder-stones-in-cats
https://truthaboutpetfood.com/grain-free-equals-peas-peas-and-more-peas/
If your ferret has been diagnosed with stones - please request that your vet send the stones to the University of Minnesota (contact info below) to aid them in their research. Link to the original pdf document here.
Click above link to read an excellent article on kidney/ bladder stones in ferrets. *Note this information quoted from the article:
"Uroliths are usually struvite, except for ferrets on a grain-free commercial diet, novel protein or diet with legumes such as peas; ferrets on grain-free diets seem to develop cystine stones."