The Adventures of Black Beauty (1972)

S02E07 The Medicine Man

Mr. Joskins is peddling dubious remedies, causing several of Dr. Gordon's patients to fall ill. In retaliation, Joskins sabotages Beauty's girth strap, resulting in Kevin getting hurt while riding. Although Albert first suspects the saddle maker, Surtees, he eventually uncovers the real culprit behind the incident.