Model of Hyperalgesia Associated with Lameness in Dairy Cattle

摘要

The nociceptive response was evaluated in dairy cattle after injection of a solution of formalin (4%) in the the external claw hoof. The nociceptive response in cows exhibited a biphasic time course behavior to pain stimulus similar to the one described in trials of formalin test in different laboratory animals. The cortisol plasma concentration after injections of formalin was high during the two phases of the pain response showing a correspondence with clinical nociceptive behaviors. The 4 % formalin injections in claw hoof in cows can be used to evaluate the possible mechanisms of anti-nociceptive drugs of central and peripheral actions. Besides, it is a reversible model; it does not need complicated equipment and it is simple to be carried out by personnel with certain experience in cow lameness. This nociceptive model might be useful to research the therapeutic role of analgesic and anti-inflammatory drugs of short half life in the modulation of hyperalgesia associated with lameness in dairy cattle.