Efficiency of 5-Hydroxytryptamine Receptor Blockade as Therapeutic Measure During Acute Respiratory Distress Syndrome in Double-Muscled Cattle

During this investigation, which involved 58 Belgian White and Blue double-muscled calves affected by a naturally occurring Acute Respiratory Distress Syndrome, the clinical efficiency of a 5-HT2 receptor blockade with metrenperone (group A) was compared to the efficiency of a non-steroidal (flunixine meglumine--group B) and a steroidal (prednisolone sodium succinate--group C) antiinflammatory drug. Each animal of this trial was treated with ceftiofur sodium as antimicrobial agent. A clinical score and a breathing score were calculated at each step of the investigation period, i.e. before (T0) and 1 hour (T1), 12 hours (H), 24 H, 48H and 168 H (T3) after the first treatment, the interval 12H-48H being considered as period T2. Three clinical parameters were also taken into account separately: rectal and peripheral temperatures and heart rate. A significant improvement of the clinical score was registered at T2 in group A and at T3 in groups A and B, while this score did not significantly change in group C. In group A, the breathing score was significantly improved at T2 and T3, but not in groups B and C. Peripheral and rectal temperatures recorded at T1 were, in group A, significantly increased and decreased respectively, but not significantly changed in groups B and C. The proportions requiring change of treatment during the investigation period were significantly (P = 0.022) different in the three groups, being 5.6, 21.4 and 50.0% in groups A, B and C respectively.(ABSTRACT TRUNCATED AT 250 WORDS)