Uroliths may have in its composition organic and minerals. There are multifactorial mechanisms involved in urolith formation however, the complete pathophysiology is yet not fully elucidated since involves epidemiological, genetic, dietary, infectious, racial factors, among others factors. Urolithiasis has been reported in humanity since 8,000 B.C until today and very common not only for humans but for dogs and cats. The classification is based on the chemical composition of the calculus, which can be formed by mineral compounds such as struvite (magnesian ammonium phosphate), calcium oxalate, calcium phosphate and silica or organic compounds such as ammonium urate, cystine and xanthine. Diagnosis involves carrying out laboratory and imaging tests and chemical and calculus physics. Some studies have been carried out to clarify the causes of urolith formation. There are seven theories that highlight the risk factors associated with its development: crystallization, inhibitor deficiency, matrix theory, colloidal theory, ionic, fixed growth theory and finally, renal cell injury theory. Knowing these theories aid in the correct understanding of the pathophysiology but mostly is necessary to understand animal and the environment factors together for a better treatment approach and prevention. Another important information is that urolith is a secondary manifestation to the existing problem and its removal depends on ruling out the primary cause. The main goal to be achieved is to reduce urolith occurrence and to minimize unnecessary invasive procedures by previous urolith identification, a better understanding of urolith formation mechanisms and, consequently, their risk factors to provide correct treatment for each type of urolith formed.