Atypical myopathy in Père David’s deer (Elaphurus davidianus) associated with ingestion of hypoglycin A

Abstract

From 2004 until 2016, 21 Père David's deer (Elaphurus davidianus) have died for unknown reason at Zoo Duisburg. These deer, also known as milu, have succumbed from a myopathy that occurred seasonally in autumn and in spring. The clinical signs shown by the animals closely resembles those of a disease called equine atypical myopathy (EAM), which is formerly known in horses. The cause for EAM in Europe was found in the ingestion of hypoglycin A, contained in samaras and seedlings of the sycamore maple tree (Acer pseudoplatanus). To test the hypothesis that the mortality of milus was caused by ingestion of hypoglycin A, 79 sera from all zoos and wildlife parks that have kept milus in Germany and Austria, including 19 diseased and 60 healthy animals, were used. Selected biochemical values and additionally hypoglycin A, methylenecyclopropyl acetic acid-carnitine (MCPA-carnitine), and acylcarnitines, which have been found in horses suffering from EAM, were determined. The results showed greater values of serum activities of creatine kinase (P < 0.001) and aspartate aminotransferase (P < 0.001) in diseased milus comparing to healthy ones confirming a myopathy in affected animals. Moreover, hypoglycin A and MCPA-carnitine were found in the blood of Père David's deer and thus, hypoglycin A intoxication was considered to be a potential cause for the myopathies by ingestion of sycamore maple samaras that were present in the enclosure of the affected animals. Hypoglycin A values were greater in diseased animals (P < 0.01) as well as MCPA-carnitine levels (P < 0.05). Additionally, affected milus showed greater C5-OH-carnitine (P < 0.01) and C6-carnitine (P < 0.001) values. Until now hypoglycin A intoxication was only known in the family of Equidae, in humans, and in laboratory rats, and it has not been previously described in other zoological families. Comparing to horses, ruminants do have a different digestive tract and it will need further investigation to find out if several factors are involved to trigger an outbreak in ruminants.

Equine atypical myopathy: consumption of sycamore maple seedlings (Acer pseudoplatanus ) by pastured horses is driven by seedling maturity and might be associated with phenolic compounds

“…Of Père David's deer (Elaphurus davidianus), a grazer, 52 altogether 19 lethal cases of atypical myopathy from 2004 to 2016 occurred not later than from September until early March in zoos. 9 The photo in the latter paper unequivocally showed stage 2 seedlings that were dominating the enclosures of the affected ruminants.…”

“…Recently, the disease has also been proven in Père David's deer captured in zoos. 9 Hypoglycin A in fruits of the sycamore maple varies between 0.69 µg/mg fresh weight (FW) and 1.59 µg/ mg FW. 10 In most juvenile seedlings, it ranged between 2.05 µg/mg FW 11 and 3.40 µg/mg FW; 12 in seedlings with primary leaves a hypoglycin A concentration of 2.39 µg/mg FW has been reported.…”

Temporal and spatial dynamics of gastrointestinal parasite infection in Père David’s deer

“…The Père David’s deer was once widely distributed along the Yangtze and Yellow Rivers ( Hu & Jiang, 2002 ). Owing to anthropogenic and natural pressures, such as hunting, rapid habitat reduction, and climate change ( Bunert et al, 2018 ; Zhang et al, 2018 ), it became extinct in the wild in China, during the early twentieth century ( Ohtaishi & Gao, 1990 ). Fortunately, the Père David’s deer had been introduced into Europe ( Jiang, Kaji & Ping, 2016 ).…”

Answers to the Frequently Asked Questions Regarding Horse Feeding and Management Practices to Reduce the Risk of Atypical Myopathy

“…Thanks to the European surveillance network, we now know that several Père David's deer (Elaphurus davidianus) have succumbed from this intoxication in different zoos in Germany. This indicates that ruminants pasturing in the vicinity of sycamore trees may also be intoxicated [16].…”