Effects of intra-articular injections of bufexamac suspension in healthy horses.
OBJECTIVE
To evaluate the effects of intra-articular (IA) injections of bufexamac in horses, focusing particularly on the effects of bufexamac on articular cartilage.


METHODS
20 Standardbreds.


METHODS
Horses were randomly allocated into 4 groups consisting of 5 horses each, and 20, 60, or 100 mg of bufexamac or 1 ml of sterile saline (0.9% NaCl) solution (control) was injected into 1 intercarpal joint at weekly intervals for 6 treatments (days 0, 7, 14, 21, 28, and 35). Clinical signs and results of hematologic, serum biochemical, and synovial fluid (SF) analyses and radiography were used to evaluate treatment effects. On day 49, all horses were euthanatized; gross necropsy and histologic examinations of internal organs and articular tissues were performed. Glycosaminoglycan concentration of the articular cartilage was evaluated in safranin O-stained sections by use of a semiquantitative microspectrophotometric method.


RESULTS
No systemic signs were observed. Temporary mild to moderate heat and effusion were the only clinical signs observed in a number of joints after IA injections and more often only in the 100 mg group, compared with controls. The 100 mg dose resulted in significant increases in SF WBC counts, with relative neutrophilia and SF total protein concentration 24 hours after injection (day 1). No lesions suggestive of toxic effects were detected at necropsy or on histologic examination. No changes in articular cartilage glycosaminoglycan concentration were detected.


CONCLUSIONS
Six injections of 20, 60, or 100 mg of bufexamac at weekly intervals did not cause any untoward systemic or local effects. These data suggest that bufexamac is a safe nonsteroidal anti-inflammatory drug for IA administration in horses.
Suominen
M M
MM
Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine, Helsinki University, Finland.
Tulamo
R M
RM
Anttila
M O
MO
Sankari
S M
SM
Király
K
K
Lapveteläinen
T
T
Helminen
H J
HJ
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D002019:Bufexamac / Q000008:administration & dosage / Q000494:pharmacology*; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005552:Forelimb / Q000000981:diagnostic imaging / Q000187:drug effects; D006025:Glycosaminoglycans / Q000032:analysis; D006651:Histocytochemistry / Q000662:veterinary; D006736:Horses / Q000378:metabolism*; D007270:Injections, Intra-Articular; D008297:Male; D011859:Radiography; D011897:Random Allocation; D013535:Suspensions; D013582:Synovial Fluid / Q000737:chemistry
D000894:Anti-Inflammatory Agents, Non-Steroidal; D006025:Glycosaminoglycans; D013535:Suspensions; D002019:Bufexamac