Effectiveness of administration of phenylbutazone alone or concurrent administration of phenylbutazone and flunixin meglumine to alleviate lameness in horses.
OBJECTIVE
To determine the effectiveness of administering multiple doses of phenylbutazone alone or a combination of phenylbutazone and flunixin meglumine to alleviate lameness in horses.


METHODS
29 adult horses with naturally occurring forelimb and hind limb lameness.


METHODS
Lameness evaluations were performed by use of kinematic evaluation while horses were trotting on a treadmill. Lameness evaluations were performed before and 12 hours after administration of 2 nonsteroidal anti-inflammatory drug (NSAID) treatment regimens. Phenylbutazone paste was administered at approximately 2.2 mg/kg, PO, every 12 hours for 5 days, or phenylbutazone paste was administered at approximately 2.2 mg/kg, PO, every 12 hours for 5 days in combination with flunixin meglumine administered at 1.1 mg/kg, IV, every 12 hours for 5 days.


RESULTS
Alleviation of lameness was greater after administration of the combination of NSAIDs than after oral administration of phenylbutazone alone. Improvement in horses after a combination of NSAIDs did not completely mask lameness. Five horses did not improve after either NSAID treatment regimen. All posttreatment plasma concentrations of NSAIDs were less than those currently allowed by the United States Equestrian Federation Inc for a single NSAID. One horse administered the combination NSAID regimen died of acute necrotizing colitis during the study.


CONCLUSIONS
Administration of a combination of NSAIDs at the dosages and intervals used in the study reported here alleviated the lameness condition more effectively than did oral administration of phenylbutazone alone. This may attract use of combinations of NSAIDs to increase performance despite potential toxic adverse effects.
Keegan
Kevin G
KG
Department of Veterinary Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
Messer
Nat T
NT
Reed
Shannon K
SK
Wilson
David A
DA
Kramer
Joanne
J
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000627:therapeutic use; D003002:Clonixin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018592:Cross-Over Studies; D004359:Drug Therapy, Combination; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D007794:Lameness, Animal / Q000188:drug therapy*; D008297:Male; D010653:Phenylbutazone / Q000008:administration & dosage* / Q000627:therapeutic use*
D000894:Anti-Inflammatory Agents, Non-Steroidal; C014558:flunixin meglumine; D010653:Phenylbutazone; D003002:Clonixin