CRI of butorphanol decreased lameness only at 8
hours. Nonetheless, the results should be interpreted
with caution, as two animals required rescue analgesia
(Dr. Carregaro’s evaluation), and the lameness scores
were higher than those after morphine and methadone
treatment, demonstrating a clinical difference. Furthermore,
if the lameness scores indicated by Dr. Dória were
considered for establishing rescue analgesia, not two but
rather five horses should have received it, demonstrating
the ineffectiveness of CRI with butorphanol. Although the
observers were experienced in the evaluation of lameness
in horses, it should be noted that variations can occur,
mainly because of the use of subjective scales [32], thereby
resulting in differences among the authors’ scores.