A collagen dysplasia in a greyhound bitch

A 10-month-old greyhound bitch was referred to the Massey University Small Animal Clinic in January 1979, with a history of frequently occurring skin lacerations, especially of the feet and limbs. Clinical findings included multiple skin scars, lacerations and hyperextensibility of the skin. Investigations showed an increased extensibility index of the skin and a sevenfold reduction in its tensile strength, as compared with that of a normal greyhound. On light microscopy dermal collagen fibres appeared to be slightly decreased in density and more whorled in appearance than that of normal sections. Electron microscopy showed dermal collagen fibrils and bundles which were largely normal, but areas could be found, in the papillary layer of the dermis, where malformed fibrils were prominent, and other areas showed disorganisation of fibrillar packing. These findings indicated that this bitch had features of a collagen fibrillogenesis disorder similar to some of those described in the various forms of Ehlers-Danlos syndrome in man, and cats and mink. Whether the disease is inherited in the greyhound breed has not yet been determined.