There are many urinary stones seen in animals among them these are some important one 1)calcium stone They are calcium oxalate , calcium carbonate. In Horses calcium carbonate is the most common one. Calcium oxalate results from high calcium, eating beetroot tops etc 2) struvite They are ammonium magnesium phosphate which are formed in alkaline urine. They are associated with urease positive bacteria like staph,Proteus,klebsella which hydrolyses urea to ammonia. They are radiopaque. 3) urate Seen in acidic Stone . They are radiolucent in x-ray so can't see but can be seen in CT scan. Dalmatian are predisposed to this because of genetic defect. 4) cystine stone They are seen due to tubular defect which can't absorb cystine Risk factors in general are Dehydration Hypercalcemia Hyperuricemia Rx- diet change, maintaining pH, proper hydration, surgery etc