[anonymously]

Who told you he was allergic to chicken? He probably has a food sensitivity, food allergies are rare. Did you discuss this with the veterinarian that is treating him? If the vet advises you to use the food I would do so.

Also, there is a lot of information at this site regarding bladder stones. Per the search engine here: /forums/search/struvite/
/forums/search/bladder+stones/
and allergies: /forums/search/allergies/

See my posts, come back if you have more questions…..