In HYPP, CK and AST levels would be within the reference range.

In HYPP, CK and AST levels would be within the reference range.

• A. Elevated above reference.
• B. Within reference interval.
• C. Decreased below reference.
• D. Highly variable.

Answer: (B)

CK and AST are enzymes that indicate muscle injury when they rise in the blood. HYPP causes episodic weakness but does not usually cause continuous muscle damage. Between episodes, there isn’t ongoing muscle injury, so CK and AST typically stay within their normal reference ranges. You’d only expect elevations if a horse is having an acute attack or after strenuous exertion that causes muscle breakdown. So, the statement that they would be within the reference range fits the usual pattern, whereas elevations would be expected only during an attack, not as a constant finding. Decreased levels are not typical, and values aren’t inherently highly variable unless an episode or exertional rhabdomyolysis is occurring.

CK and AST are enzymes that indicate muscle injury when they rise in the blood. HYPP causes episodic weakness but does not usually cause continuous muscle damage. Between episodes, there isn’t ongoing muscle injury, so CK and AST typically stay within their normal reference ranges. You’d only expect elevations if a horse is having an acute attack or after strenuous exertion that causes muscle breakdown. So, the statement that they would be within the reference range fits the usual pattern, whereas elevations would be expected only during an attack, not as a constant finding. Decreased levels are not typical, and values aren’t inherently highly variable unless an episode or exertional rhabdomyolysis is occurring.