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.

TVT, also known as infectious sarcoma, venereal granuloma, transmissible lymphosarcoma or sticker tumour is a benign reticuloendothelial tumour that affects particularly mucosa of external genital organs and rarely internal genital organs in dogs of both genders. TVT is usually transmitted by coitus but also can be transmitted by licking, sniffing, biting,and scrabbling of the tumour affected area or through damaged skin of mucosa. Transmissible venereal tumour (TVT) is usually observed in stray animals live in tropical and subtropical lands. The affected animals are usually within 9-13 months of age and with high sexual activity. Tumour is frequently located in posterior vagina and vestibulovaginal junction. The averagechromosome count of TVT cells is 59 (57- 64). TVT specific antibodies were found in blood samples of affected animalswhich suggest that they may have a role in natural regression mechanism. The primary objective of tumour treatment is total elimination by surgery, radiotherapy, immunotherapy and/or chemotherapy. Controlling of the disease is very difficult because stray dogs are carriers.