Histological changes in cruciate ligament (CLs) with mild degeneration. This image is from a section of normal Greyhound cranial cruciate ligament (CCL). There is a mixed cell population (spindle and oval, black arrows), regular staining of the collagen bundles (yellow arrows) and well defined interbundle areas (white arrows) (A) (Stain: H&E, CCL, ×40). Minimal oxytalan fibre (OF) staining (white arrow) is seen in this image of a section of normal Greyhound cranial cruciate ligament (CCL). (B) (Stain: Miller’s stain, CCL, ×40). Loss of cell density, collagen density and architecture along with degenerative change (pericellular halos) are demonstrated in this section (C) (Stain: H&E, CCL, x40). An image from same section as C shows marked pericellular oxytalan fibre staining of most degenerative cells, with moderate interbundle and substance staining (D) (Stain: Miller’s stain, CCL, ×40). Marked interbundle oxytalan fibre staining (white arrows) is seen along with widespread and marked pericellular staining (yellow arrows) and a moderate degree of CL substance stainings (E) (Stain: Miller’s stain, CCL, ×40). An area of complete loss of collagen architecture with mineralisation is seen and is considered to be fibrocartilaginous change (FC) (F) (Stain: H&E, CaCL, ×40). In this image from the same section as F, the area of fibrocartilaginous change (FC) shows a dense and fine meshwork of microfibrils (MFs) (G) (Stain: Miller’s stain, CaCL, ×40). Magnification bars, 100 μm.