Abstract. Between January 1976 and September 1987 renal medullary amyloidosis (RMA) was diagnosed in 17 Dorcas gazelles; the necropsy prevalence rate was 17/32 (53%). The most severe amyloid deposits were in the renal medulla; glomeruli were spared. Renal cortical lesions of interstitial fibrosis and tubular atrophy and dilatation significantly correlated with RMA (P < 0.01) and were considered to be secondary changes.There were varying degrees of lymphoplasmacytic inflammation and tubular cast formation which did not significantly correlate with RMA. Amyloid was confirmed histochemically and by electron microscopy and was identified as AA type by the permanganate method. Progressive renal failure was the cause of death or necessitated euthanasia in 7/17 (4 1 Yo) gazelles. RMA in Dorcas gazelles does not appear to be familial. A high prevalence of chronic or recurring Actinomyces (Corynebacterium) pyogenes infections may be an important factor.Currently, classification of the amyloidoses is based in part on the nature of the fibril p r~t e i n .~ Reactive systemic amyloidosis, in which the fibril protein (AA) is believed to be derived by proteolytic cleavage from an acute phase protein (SAA), is the most common form in manZZ and is the only form of systemic amyloid reported in nonhumans.' Any organ can be involved in reactive systemic amyloidosis, but renal involvement occurs with greatest f r e q u e n~y . '~.~~ Renal amyloid also has the most serious consequences, since deposition of amyloid in glomeruli causes disruption of the glomerular filtration bamer, with resultant proteinuria and associated sequelae. l 5 In addition, deposition of amyloid in the pentubular interstitium can lead to ischemia and pressure atrophy of nephrons with subsequent interstitial scarring and loss of renal function.I5Involvement of the renal medulla with amyloid is rare in man26 and most animals,I5 but may be the predominant form of renal amyloidosis in cats3J5J8 and ~a t t l e .~J~J~ In cattle, there is a spectrum from predominantly glomerular to predominantly medullary amy10idosis;~~l~ the glomerular form can lead to the nephrotic ~y n d r o m e~~J~J~ as in other species, but the medullary form is usually subclinical.I0We have identified a syndrome of renal medullary amyloidosis (RMA) in a herd of Dorcas gazelles at the National Zoological Park (NZP). In contrast to medullary amyloidosis in cattle, RMA in Dorcas gazelles frequently leads to renal failure and death. This paper reports the occurrence and describes the gross and light microscopic features of renal medullary amyloidosis in Dorcas gazelles. The clinical aspects of the disease will be published elsewhere. Materials and MethodsDorcas gazelles are small ruminants indigenous to desert regions of Northeast Africa. Body weights in adults range from 10 to 15 kg. The National Zoological Park (NZP) maintains a herd of Dorcas gazelles with an average year-end population of about 20 animals. Twice yearly each animal is treated prophylactically with anthelminthics, and a complete...

Elderly patients with hip fractures treated at our trauma center had improved clinical outcomes after the implementation of a multidisciplinary care pathway.