Health monitoring and disease surveillance of free-ranging formosan pangolins (Manis pentadactyla pentadactyla) in Southeastern Taiwan

Abstract

Pangolins (Pholidota:Manidae), also known as scaly anteaters, are nocturnal, insectivorous mammals found in several Asian and African countries. There are eight species of pangolins found in Asia and Africa. Among them, the Chinese pangolin (Manis pentadactyla) is an endangered insectivorous mammal found only in Asia. Formosan pangolin (Manis pentadactyla pentadactyla) is sub-species and distributes only in Taiwan. The present study was conducted to monitor the health status and survey the diseases of free-ranging Formosan pangolins. Hematology and serum chemistry reference intervals are critical for evaluating an animal’s well-being and can be useful for clinical diagnostic purposes. Currently, there are no such reference intervals available for any pangolin species. The purpose of the present study was to establish reference intervals for hematology and serum biochemical analytes, and some basic clinical findings, in Formosan pangolins. Reference intervals for the hematology, serum chemistry and basic clinical findings (body weight, heart rate, body temperature, blood oxygen saturation) were calculated from 100 clinically healthy Formosan pangolins (51 males and 49 females) using parametric and non-parametrical percentile methods. In addition, seasonal, age group and sexual differences for all the analytes were analyzed. No significant differences in the reference values were found between males and females, except for body weight. However, significant seasonal differences were observed in heart rate, body temperature, serum alanine aminotransferase and lipase activities, and phosphate concentrations. The variables, which were significantly different between adult and sub-adult Pangolins, were heart rate, MCH, creatinine, total protein, phosphate, glucose, potassium, and amylase. Seasonal and age group differences should be taken into consideration while using these reference intervals. Pathological studies are helpful in the diagnosis and investigation of wildlife diseases. Pathological findings in pangolins have not been well documented. The present article reports the pathological findings of 14 freeranging Formosan pangolins. External injuries and superficial wounds (43%, 6/14) were common finding in gross examination and were mostly found in the legs. Respiratory system (78%, 11/14) lesions included interstitial pneumonia, atelectasis and emphysema. Hepatic lesions (43%, 6/14) included necrosis, bile duct hyperplasia, lipidosis and extensive hepatocyte degeneration. Parasites were detected in 57% of pangolins (8/14) studied and included both endoparasites and ectoparasites. Urinary system (21%, 3/14) lesions were interstitial nephritis and nephrolithiasis. Brain lesions were found in 3 pangolins and included cerebral edema and hemorrhage, and ventriculitis. Additional pathological lesions included thyroid gland hyperplasia and left ventricular hypertrophy. The presented pathological findings can aid in the understanding of diseases of pangolins and will contribute knowledge to future investigations on diseases of pangolins In recent years, there has been an increase in spread of tick-borne diseases in both humans and animals worldwide. Currently, limited information is available on ticks and associated pathogens infesting pangolins. The objective of the present study was to survey the ticks and associated pathogens in the Formosan pangolin population in Southeastern Taiwan. Freeranging Formosan pangolins captured during ecological survey were examined for the presence of ticks. DNA extracted from these ticks was used to identify the tick species and also to detect the tick-borne pathogens, by molecular methods. We found 25% (13/52) of the pangolins captured during 2012-2014 infested with ixodid ticks. A total of 21 ticks were collected and 3 tick species were identified: Haemaphysalis hystricis (14/21), Haemaphysalis formosensis (2/21) and Amblyomma testudinarium (5/21). We detected four different tick-borne pathogens, where one was identical to Anaplasma sp. strain An.H1446 while others showed close resemblance to Rickettsia conorii subsp. caspia A-167, Ehrlichia sp. TC251-2 and Cytauxzoon spp. respectively. The present study is the first survey of the ticks infesting the free-ranging Chinese pangolins and pathogens harboured by these ticks. This information is important to know the diversity of ticks and tick-borne pathogens, and its conservation significance to pangolins and other sympatric wildlife. Important future step should be regular surveillance of ticks and tickborne diseases at human-domestic animals-wildlife interface, which can provide a useful insight into the dynamics of these pathogens and can help control and prevent outbreak of such zoonoses. The findings from the present study represent a valuable resource for assessing the health of Formosan pangolins, and contribute towards the conservation of this endangered mammal.