What is the most common type of urinary calculus in horses?

What is the most common type of urinary calculus in horses?

• A. Calcium phosphate
• B. Calcium carbonate
• C. Uric acid
• D. Magnesium ammonium phosphate

Answer: (B)

Calcium carbonate stones form most commonly in the horse urinary tract because the typical equine diet and urinary environment promote precipitation of calcium carbonate more than other minerals. Forage-based diets provide substantial calcium, and the horse’s urine tends to be at a pH and saturation level that favors CaCO3 formation, especially in the bladder and urethra. These stones are often radiopaque, making them detectable on imaging. Other minerals like magnesium ammonium phosphate (struvite), calcium phosphate, or uric acid can form stones, but they are far less common in horses due to the usual urinary chemistry and dietary patterns.

Calcium carbonate stones form most commonly in the horse urinary tract because the typical equine diet and urinary environment promote precipitation of calcium carbonate more than other minerals. Forage-based diets provide substantial calcium, and the horse’s urine tends to be at a pH and saturation level that favors CaCO3 formation, especially in the bladder and urethra. These stones are often radiopaque, making them detectable on imaging. Other minerals like magnesium ammonium phosphate (struvite), calcium phosphate, or uric acid can form stones, but they are far less common in horses due to the usual urinary chemistry and dietary patterns.