Effects of pre-shipping marbofloxacin administration on fever and blood properties in healthy Thoroughbreds transported a long distance

The present study evaluatedthe effects of single-dose marbofloxacin in protecting horses against fever associatedwith transportation using 48 healthy Thoroughbreds. All horses were premedicated withinterferon-α (0.5 U/kg, sublingually, every 24 hr) for 2 days before transportation and onthe day of transportation. Horses were randomly assigned to receive marbofloxacin (2mg/kg, IV, once; MRFX group), enrofloxacin (5 mg/kg, IV, once; ERFX group) or saline (0.9%NaCl) solution (10 ml, IV, once; control group) ≤1 hr before beingtransportation. Each group contained 16 horses (8 males, 8 females). Horses weretransported 1,210 km using commercial vans over the course of approximately 26 hr.Clinical examinations and hematologic analyses were performed on all horses both beforeand after transportation. Post-transportation neutrophil to lymphocyte ratios weresignificantly lower in horses in the MRFX group compared with the control horses. Theserum amyloid A levels were significantly lower in horses in the MRFX group and ERFX groupcompared with the control horses. Regarding the post-transportation rectal temperatures,fever was detected in 0 horses and 1 horse in the MRFX and ERFX groups, respectively,whereas fevers exceeding 39.1°C were detected in 2 horses in the control group.Additionally, the number of essential post-transportation treatments provided byveterinarians was reduced 3-fold in the MRFX and ERFX groups compared with the salinegroup. MRFX provided ERFX-like protection against fever associated with long-distancetransportation, yielding significantly better protection than saline. Administration ofMRFX just before transportation deserves a further study for efficacy in preventing horsefever associated with transportation.