Acute phase protein concentrations following serial procaine penicillin G injections in horses

Background Acute phase protein (APP) measurement is used to detect inflammation. Intramuscular (IM) injections could cause tissue injury and induce an acute phase response (APR). Objectives To evaluate the effects of IM procaine penicillin G (PPG) injections on APP concentrations in horses. Study design Prospective longitudinal design. Methods PPG was administered intramuscularly to six horses, twice daily, for 5 days. Plasma fibrinogen (FIB), serum amyloid A (SAA), haptoglobin (HAP), creatine kinase (CK), and aspartate aminotransferase (AST) were quantified daily for 5 days before the first injection, during the course of administration, and for 4 days after the final dose. Analytes were quantified every other day for the remaining 16 days. Data were compared using a parametric or non‐parametric repeated measures ANOVA and a Tukey's or Mann–Whitney rank sum test, respectively. Significance was set at p