A beef heifer close to parturition is down and won't get up. The fetus is alive and there was a recent change from grain to roughage. What is the most appropriate initial diagnostic test to assess a likely metabolic disorder?

A beef heifer close to parturition is down and won't get up. The fetus is alive and there was a recent change from grain to roughage. What is the most appropriate initial diagnostic test to assess a likely metabolic disorder?

• A. Check calcium and phosphorus levels
• B. Perform a urinalysis
• C. Take a blood culture
• D. Perform a digital rectal exam

Answer: (A)

When a near-term cow is recumbent, a top metabolic issue seen at this stage is hypocalcemia (milk fever). Calcium is required for muscle contraction and normal nerve and heart function, so a sudden drop around calving makes the cow unable to stand or move. The best initial diagnostic step is to measure serum calcium (and ideally phosphorus as part of the panel). A low calcium level directly supports milk fever and quickly points you toward urgent treatment with calcium. Other tests don’t address the suspected problem: urinalysis won’t confirm calcium status, a blood culture looks for infection, and a digital rectal exam won’t reveal the metabolic deficit causing recumbency.

When a near-term cow is recumbent, a top metabolic issue seen at this stage is hypocalcemia (milk fever). Calcium is required for muscle contraction and normal nerve and heart function, so a sudden drop around calving makes the cow unable to stand or move. The best initial diagnostic step is to measure serum calcium (and ideally phosphorus as part of the panel). A low calcium level directly supports milk fever and quickly points you toward urgent treatment with calcium. Other tests don’t address the suspected problem: urinalysis won’t confirm calcium status, a blood culture looks for infection, and a digital rectal exam won’t reveal the metabolic deficit causing recumbency.