Tendon in horse is the most important type of connective tissue which connects muscle to bone, constituting a vital component of the musculoskeletal system, by enabling movement. Tendons suffer from a wide range of disorders, which includes different types of mechanical injuries and degenerative diseases. The sample population was a deep digital flexure tendon (DDFT) at mid-metacarpal region of thirty adult horses examined using scanning electron microscopy (SEM). Sex distribution was not taken into account. Changes in its structural organisation due to aging following tendon degeneration was unknown. The complex structures of tendon and its distinctive characteristics have been well demonstrated by SEM techniques. The tendon structure under SEM showed a dense, regular connective tissue arrangement thatreflects the mechanical requirement of this tissue. It is defined by thick regular bundles of longitudinal collagen fibres arrangedin a zig-zag conformation. All tendons examined from these horses had no history of deep digital flexure tendinitis and were allmacroscopically normal. The tendon showed a hierarchical structure, with collagen molecules forming fibrils (50 nm to 500 nm), which in turn comprise a fascicle (50 μm to 300 μm), and fascicles were aligned along the longitudinal axis of the tendon.

A number of studies have measured collagen fibers and collagen
deposition in wound healing process with advances imaging techniques. However, these are performed by complicated methods and need specific tools. In search of the easier ways in routine histopathological laboratory, collagen measurement and staining pattern of wound healing process were observed in wounded skin of Sprague Dawley’s rat by using two different stains which are standard haematoxylin and eosin (H&E) and modified Masson’s
trichrome staining (MT). The comparison between these staining in wounded tissues was made to evaluate the advantages and disadvantages of both staining in wound healing study for 21 days postwounding. Tissues which stained with MT staining was then evaluated its collagen re-organization and density by using polarized light microscope with the aid of image analyzer software. Results showed that tissues stained with standard H&E could not be used to measure and differentiate the collagen deposition which is contradictory to MT staining. Wounded tissue stained with MT staining has showed a clear view of collagen fibers deposition
and re-organisation compared to H&E staining. This finding could validate the using of modified MT staining which leads to accurate histopathological analysis and observation in wound healing study.