Evo was written concerning the issue of cystine stone formation and
peas in the diet. Below is their response.

Cystine stone formation in ferrets is primarily an inherited disorder
in which the pet has an abnormal loss of the amino acid cystine into
the urine. Diets high in cystine and/or methionine (a precursor of
cystine) from high protein-containing ingredients or from supplemental
amino acids can contribute to the amount of cystine lost into the
urine, and therefore, increase risk of cystine stone formation.

Of the cases reported, many (but not all) of the ferrets who have
developed cystine stones have been on pea containing diets designed for
the management of food allergies. At this point there is no evidence
that peas are directly associated with the development of the cystine
stones, and it is thought that the cystine and methionine amino acid
content of the diet (including free methionine amino acid
supplementation) is likely playing the main role. It should be noted
that all of the pea-containing diets that have been associated with
cystine stone formation have also been supplemented with methionine.
To date, we have received no reports of any ferrets developing cystine
stones while being fed EVO Ferret food.

-- 
Debbie, Kindness Matters Ferret Rescue
Sponsor a rescue ferret for only $5 per month!

[Posted in FML 7662]