Increased type-I collagen has been reported in chronic degenerate Achilles tendinopathy [42,43] this is at variance with the findings of the current study that identified no significant difference between gene expression of COL1A2 in normal adult tendon and tendinopathy of the SDFT of more than 6 mths duration in the horse. This evidence concerns the gene COL1A2 and disease of the tendon.