|Sample Requirement||Turnaround Time|
|Serum||Same working day|
Creatinine is formed in muscles from creatine breakdown and is excreted via the kidneys. In normal horses, daily production and excretion are remarkably constant, leading to its use as an arithmetic constant for use with urinary fractional excretion rates (see Urinary Fractional Clearance). Serum elevations reflect renal malfunction (reduced glomerular filtration), levels being controlled by excretion rate. This may occur in horses with pre-renal (e.g. circulatory disturbances, dehydration or shock), renal or post-renal disease. Measurement of urine specific gravity and fractional excretion of electrolytes may help to differentiate pre-renal and renal azotaemia.
When uroperitoneum (post-renal azotaemia) is suspected it can be useful to compare peritoneal fluid and serum creatinine concentrations; a ratio of greater than 3:1 confirms uroperitoneum.
Decreases may be physiological (eg decreased muscle mass), related to increased glomerular filtration rate, or decreased production (eg liver disease).
|Adult Non-Thoroughbred Horses||85-165|
|Neonatal Thoroughbred Foals (24-48hrs old)||97-188|
|Older Thoroughbred Foals (approx. 3 weeks old)||97-138|
|Yearling Thoroughbred Horses||93-125|
|Two-Year-Old Thoroughbred Horses in Training||110-160|
|Three-Year-Old Thoroughbred Horses in Training||118-167|
|Adult Thoroughbred Horses at Stud||87-112|