CUTANEOUS ASTHENIA IN ONE DOG

Cutaneous asthenia was diagnosed in a 6-month-old bitch of the Fila Br asiliero breed. The animal was also suffering from juvenile poyderma, which was successfully cured. Owing to poor prognosis of the cutaneous asthenia the dog was euthanatized at 13 months of age. No pathologica l lesions were observed in the animal's internal organs. Histology of the skin revealed a loose arrangement of the collagen connective tissu e in the dermis. The collagen fibres were of variable thickness, tortu ous and fragmented. The thick fibres consisted of a homogeneous axial part, which contained neutral proteoglycans, and a fibrillar periphery . These peripheral fibrils were composed of acid proteoglycans, contai ned vimentin and bound ConA, PNA, RCA, SEA and WGA lectins. Elastic fi bres were absent. Considering the fact that the central zone of collag enous fibres in our case of cutaneous asthenia had the same structural and staining characteristics as normal fibres, our findings suggest t hat the maturation of these fibres proceeds from their axial segments towards the periphery. We assume that the pathogenesis of cutaneous as thenia consisted in retarded or arrested maturation of collagen fibres .