Abstract

    Fluoroquinolone (FQNL) antibiotics have been used widely in horses because of their broad-spectrum bactericidal activity and relative safety, however, their use is not without risk. Tendonitis and spontaneous tendon rupture have been reported in people during or following therapy with FQNLs. To evaluate the potential damage of enrofloxacin (ENRO) on the equine superficial digital flexor tendon (SOFT), an equine cell culture system as an in vitro model of equine tendon injury and repair was developed. The effects of ENRO on tendon cell cultures established from equine SOFT were studied. The data thus collected demonstrated that ENRO inhibited cell proliferation, induced morphological changes and altered proteoglycan synthesis in equine tendon cell cultures. Interestingly, these effects were more pronounced in juvenile tendon cells as compared to adult horses, It. is hypothesized that morphological changes and inhibition of cell proliferation is a result of impaired production of proteoglycans and other glycoproteins in the extracellular matrix of ENRO-treated tendon cells.