Sentence:  If horses exhibit a <WSD>cold-back</WSD>, it may well signify an underlying problem, but some horses that have only a <WSD>cold-back</WSD> and no other signs or performance deficit can be managed by lunging before riding or gradually tightening the girth. 
Meaning of the word marked with <WSD> tags:  A syndrome in which a horse refuses to accept anything on its back (often a symptom of chronic lower back soreness)