Serum C-reactive protein (CRP) in horses: the effect of aging, sex, delivery and inflammations on its concentration.

The study investigates how age, gender, childbirth, and inflammation affects the amount of C-reactive protein (CRP) in horse serum.

Methodology and Findings: C-reactive protein in horses

• The researchers explored the role of CRP as an acute-phase reactive protein by conducting single radial immunodiffusion (SRID) on horse serum. These tests were conducted using rabbit anti-equine CRP serum.
• They could not find detectable levels of CRP in the serum samples taken from newborn thoroughbred foals prior to them being given colostrum.
• However, the concentration of CRP in horse serum was found to rise quickly and peak at around 14.1 micrograms/ml in 12-month-old horses. Post this stage, the CRP concentration gradually lessened and settled at a low of 5.4 micrograms/ml in four-year-old horses.
• Horses that were above five years old exhibited a stable and consistent concentration of CRP in their serum, ranging from 7 to 8 micrograms/ml.

Effects of Childbirth and Inflammation on CRP Levels in Horses

• Observations on mares during the peri-natal period showed a reduction in CRP concentration in the serum two months prior to delivery. Moderate alterations were observed just before and after delivery, and a significant increase was spotted two months post-delivery.
• After intentionally introducing inflammatory stimuli in adult horses, the researchers noticed an increase in serum CRP concentration 24 hours later. Peak values of serum CRP concentration were observed three to five days post-inflammation, marking an increase of three to six times the baseline.
• The increased CRP concentration levels reverted to base line values within two to three weeks following the treatments.
• The researchers concluded from these results that CRP indeed functions as one of the acute-phase reactive proteins in horses.