COMPUTERTOMOGRAPHIC STUDY ON THE EQUINE H OOF AFFECTED BY LAMINITIS

Laminitis is an extremely painful condition which requires intensive a nd often long-term treatment, Even after months or years of therapy th e outcome might still be unfavourable, the condition prooving to be in curable. Considering the economical questions and the severe welfare c onsequences caused by this problem the importance of a reliable progno sis becomes evident. The coffin bone is suspended in the hoof capsule. The bond between the coffin bone and the wall of the hoof capsule is established by the suspensory apparatus of the coffin bone. Laminitis is the most important disease of this apparatus. X-ray and ultrasonogr aphy have turned out to be insufficient in visualising the suspensory apparatus of the coffin bone. In computertomography however pathologic al changes can be localized and demonstrated in great detail. On ct-sc ans of healthy hooves two zones of the suspensory apparatus can be dis tinguished: A section of low radiographic density adjacent to the coff in bone and a section of higher radiographic density in the periphery. The sections are separated by a distinct line levelling with the bord er of the basal third of the horny lamellae. In light cases of laminit is this line is blurred. Chronic laminitis is accompanied by excessive production of cap horn in the wall segment (scar horn in clinical ter ms) represented by a line of lower radiographic density in the ct-scan . In severe cases of chronic laminitis necrosis of the lamellar appara tus and production of new lamellae can be observed in the scan. Reacti ve changes in structure (atrophy, sclerosis) and contour (exostosis) o f the coffin bone are frequent consequences of chronic laminitis. Loca lisation and extension of these alterations are important criteria for prognosis and can be assessed in the ct-scan. In comparison to conven tional radiography, computertomography holds fundamental advantages. T ype, severity and extension of pathological changes in the suspensory apparatus of the coffin bone can be diagnosed clearly. Reactive change s of the coffin bone can be assessed. In conclusion data obtained by t he technique of computertomography offer valuable information for prog nosis and treatment strategy of laminitis.