Abstract
Systemic or reactive (AA) amyloidosis has been reported in several species of captive primates including pig-tailed macaques (Macaca nemestrina), chimpanzees (Pan troglodytes) and common marmosets (Callithrix jacchus).1-3 Amyloidosis has also been previously documented as a postmortem finding in the pygmy marmoset (Callithrix pygmaea) and is often associated with chronic inflammatory disease.4
A retrospective survey of pygmy marmoset necropsies submitted to Northwest ZooPath from 1995–2009 revealed that 38.3% (31/81) of animals older than 2 weeks of age had histologic evidence of amyloid in one or more organs. An additional nine cases were identified via survey of individual zoological institutions. The most commonly affected organs were the liver, spleen, and kidneys with amyloid deposition in 90.0%, 72.5%, and 52.5% of cases, respectively. Additional organs affected included adrenals, gastrointestinal tract, lung, heart, lymph nodes, pancreas, skin, and vasculature. The ages of affected animals ranged from 1–17.6 years, with a mean age of 7.9 years. No sex predilection was observed. The majority of cases had multiple concurrent chronic disease processes including cardiac, renal, or inflammatory gastrointestinal disease. Only two marmosets had a premortem diagnosis of amyloidosis via hepatic biopsy.
Based on the results of this survey, amyloidosis is a common postmortem finding in captive pygmy marmosets and can be a significant contributing factor in mortality of this species. Further investigation is needed to determine if genetic factors play a role in susceptibility and if earlier diagnosis and treatment of concurrent diseases can limit or prevent progression of systemic amyloidosis.
Literature Cited
1. Hubbard, G.B., D.R. Lee, K.D. Steele, S. Lee, A.A. Binhazim, and K.M. Brasky. 2001. Spontaneous amyloidosis in twelve chimpanzees, Pan troglodytes. J. Med. Primatol. 30:260–267.
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