J Zoo Wildl Med. 2026 Mar;57(1):140-147. doi: 10.1638/2025-0069.
ABSTRACT
Five of a cohort of 13 aye-ayes (Daubentonia madagascariensis) at the Duke Lemur Center (DLC) exhibited acute, nonspecific signs of lethargy and ataxia within 24 h of ingesting a meal containing avocado fruit (Persea americana) that included the skin and pit. Deaths rapidly ensued in four of the five animals within 13 h of initial symptoms. All animals that died had pericardial effusion on postmortem examination and microscopic findings of acute myocardial degeneration. After ruling out other causes, all evidence points to avocado toxicity as the cause of death. Following an analysis of the DLC deaths in 2016, all deaths in aye-ayes from 1985 to 2022 occurring at the DLC or on loan to other institutions were reviewed. An additional six cases of acute death and pericardial effusion associated with cardiomyopathy and acute myocardial degeneration were identified for a total of 10 of 27 deaths (37%) over 37 yr. This analysis led the authors to conclude that aye-ayes may be acutely sensitive to toxins present in avocado and that mortality due to avocado toxicosis in this species is more common than previously recognized. Prior stress on animals in advance of avocado consumption may have contributed to the acute myocardial degeneration and death following avocado fruit ingestion, as noted in this report. Avocado toxicosis has been reported in various avian and mammalian species, but adverse effects have not been previously noted in other lemur or primate species. This case series is of particular interest because all affected animals had regularly been fed avocado previously and some zoologic institutions routinely use avocado in diets for primates.
PMID:41926265 | DOI:10.1638/2025-0069