The most common uroliths found in feline and canine urine are:

• A. Calcium oxalate
• B. Urate
• C. Struvite
• D. Cystine

Answer: (C)

The key idea is which type of urinary stone appears most often in dogs and cats. Struvite stones, made of magnesium ammonium phosphate, are the most common uroliths in both species, especially in younger animals. They tend to form in alkaline urine and are often associated with bacterial activity that raises urine pH, promoting crystal formation. Clinically, they’re typically visible on X-rays and, if infection isn’t resistant, can often be dissolved with dietary acidification and appropriate antibiotics when needed. Other stone types—calcium oxalate, urate, or cystine—occur less frequently or only in specific situations (certain breeds, liver issues, or age), so they don’t fit as the typical presentation as well.