Hello lsweeny,
Sorry for the delay, we have been traveling the last week. Hmmm the symptoms sound like an undiagnosed lameness followed by vaguely colicky symptoms associated with a transient fever episode. As to a single cause that seems unlikely but Lyme’s disease can cause a multitude of symptoms if this is an endemic disease to your area it could be considered. Tick fever (anaplasmosis) generally has more persistent fever and presents with vasculitis and jaundice is common. Best is not to prejudge and let a thorough physical exam and targeted lab work lead you.
DrO