Fecal quality control
Compiled by Christian & Linda Schiffmann
The physiology of defecation in elephants
Elephants are megaherbivores with a mean retention time of about 24 hours (Rees 1982; Hackenberger 1987). Elephants do defecate on average around 12-16 times per 24 hours with a mean amount of five fecal boluses per defecation (Coe 1972; Ratnasooriya et al. 1994). Being hind gut fermenters, the plant fibers of their diet are shed in the feces exactly the size as they have been swallowed after being chewed. Therefore, fecal particle size is correlated to chewing efficiency in elephants. With respect to this physiology, fecal quality offers a valuable opportunity to assess an elephant’s digestive health. Accordingly, regular fecal check is strongly recommended as an integral part of continuous health monitoring in elephants under human care.
Aspects to be assessed through regular fecal checks
We recommend checking the following criteria for elephant feces in the indicated intervals:
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fecal consistency, structure and bolus size – on a daily basis
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fecal particle size – monthly
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coproscopy in order to detect intestinal parasites – 1-4 times a year (depending on regional parasite prevalence and housing conditions). In addition, fecal samples can be used to determine glucocorticoid metabolites and reproductive hormones, if this information is relevant for management decisions or scientific research.
Fecal consistency, structure and bolus size
Although fecal consistency and structure may slightly vary depending on diet composition, it usually allows the building of well-shaped and evenly sized boluses (Fig. 1a). Ideally, the boluses are compact and can be taken from the ground without breaking into pieces. They have a brown color which can tend towards slight green or yellow depending on the roughage fed. Gastrointestinal disorders as well as short-term stress may lead to reduced fecal consistency resulting in varying degrees of diarrhea (Fig. 1b-e). Not well-masticated food stuff (e.g. seeds, fruits) can be observed in the fecal boluses (Fig. 1f), as well as foreign materials which have been swallowed intentionally or unintentionally. These indicators provide information on which material the elephant has access to and on his (potentially abnormal) feeding behavior. Fecal bolus size varies with age and therefore size of an elephant (Coe 1972; Morrison et al. 2005; Leopardi et al. 2013). Elephants with improper chewing efficiency (e.g. due to molar issues), may show heavily enlarged fecal boluses as a consequence of poorly masticated roughage (Fig. 2). Such mega boluses may cause abdominal pain or even lead to constipation. In addition to the bolus size, also the total amount of feces during a 24h cycle should be checked. Showing an increased or decreased amount of feces may hint to digestive disorders or inappropriate feed intake in an elephant. Even the distribution of fecal boluses in the habitat of an elephant may tell you a story. As an example, geriatric individuals suffering from severe degenerative joint disease may not interrupt their lying rest to defecate, which can be recognized by the pattern of their defecations (Fig. 3). Taking this together, macroscopic fecal check as a daily routine can provide experts in charge with a multitude of valuable information on elephants’ (digestive) health status.
Figure 1. Fecal consistency in elephants may vary from well-shaped firm boluses in a healthy situation (a) to different degrees of diarrhea with reduced fecal consistency (b-e). Unchewed parts such as corn may offer additional information on an elephant’s food intake on the previous day (f). Picture a: Photo Courtesy of Martin Kristen. Pictures c,d and e Photo Courtesy Patrycja Kasprzak.
Figure 2. Mega boluses of different sizes (cell phone for size comparison) and in relation to regularly formed fecal boluses (upper right). Note the large plant fibers contained in the mega boluses (left). Photo Courtesy of Martin Kristen.
Figure 3. Defecation pattern of an elephant suffering from severe degenerative joint disease and therefore avoiding to interrupt its lying rest for defecation. Healthy elephants do get up from recumbency in order to defecate.
Fecal particle size
Chewing efficacy has been shown to vary during an elephant's lifetime, presumably due to continuous changes in the molar grinding surface caused by the physiological process of molar progression (Schiffmann et al. 2019). Fecal particle size as an indicator for chewing efficacy can be used to monitor these physiological changes over time and to detect pathological alterations (Fig. 4). A simple sieving method allows the determination of fecal particles by focusing on the largest fibers. This method is practical in the field and has been shown to correlate well with a sophisticated approach in the lab (Schiffmann et al. 2023). A concise description of the procedure is given in Figure 5. It is recommended to document the detected size of the ten largest fibers photographically (Fig. 6). This enables the monitoring of fiber length of an individual elephant over time. Of course, this information should be completed with parallel monitoring of the molar status, which can also be documented photographically (Fig. 7).
Figure 4. Obvious difference in fecal particle size between two female Asian elephants on the same diet, but with varying chewing efficacy. While one female with a healthy molar status was able to chew roughage as needed (a), the other female suffered from molar issues and struggled to chew properly (b).
Figure 5. Guidance for a simple sieving protocol to determine fecal particle size in elephants.
Figure 6. The size of the ten largest fibers can easily be documented photographically.
Figure 7. Ideally, molar status in the upper and lower jaw should be monitored and documented on a regular basis. We recommend a frequency of three months for photographic documentation.
Coproscopy for the detection of intestinal parasites
Basically, African as well as Asian elephants are susceptible for clinical gastrointestinal parasite infestation. Most relevant gastrointestinal parasites for elephants do belong to the trematoda, cestoda, nematoda and protozoa (Vimalraj and Jayathangaraj 2013; Abeysekara et al. 2018; Chel et al. 2020). Severe parasite loads are reported in free-ranging as well as captive elephants in the range countries with the potential for fatal outcomes (Kinsella et al. 2004; Obanda et al. 2011; Nishanth et al. 2012; Hing et al. 2013; Vimalraj and Jayathangaraj 2013; Lynsdale et al. 2017; Abeysekara et al. 2018; Kingori et al. 2020). They seem less relevant in modern zoos. Prevalence of gastrointestinal parasites seems significantly higher in free-ranging elephants compared to elephants living in human care (Abeysekara et al. 2018; Abhijith et al. 2018).
The composition of parasites seems to shift from helminth-dominated in free-ranging elephants to mostly protozoa in captive elephants, presumably due to regular anthelminthic treatment in human care (Abeysekara et al. 2018).
Based on these reports, the recommended monitoring interval heavily depends on the geographic region and the housing conditions in particular regarding feed hygiene (Fig. 8). In Western zoos annual to biannual coproscopy seems a reasonable protocol, if appropriate hygienic conditions are ensured.
Figure 8. Providing roughage in top-feeders (e.g. hay nets) can significantly reduce contamination of food items and ensure hygienic conditions. Especially for Asian elephants, these feeders should not be too high (like on this photo) as this may place too much strain on the flexibility of the spine, which could result in damage to the spinal joints.
In order to cover the intestinal parasite species relevant for elephants, the fecal sample should be examined both by sedimentation as well as flotation. Table 1 gives an overview on which detection method is appropriate for which parasite species. Various treatment options are available (Fowler and Mikota 2006). If anthelmintic treatments are administered a subsequent coproscopy should be conducted to confirm the effectiveness of the treatment (Lynsdale et al. 2015).
Table 1. Appropriate detection methods for the parasite classes most relevant in elephants
Summary
Regular fecal checks provide a non-invasive, simple and cheap opportunity to monitor an elephant’s molar and digestive health. Fecal consistency, structure and fiber length provide valuable information and should be checked on a regular basis. In combination with parasitology in the lab on an interval appropriate for the parasite prevalence in the region, these fecal checks present an important part of health monitoring in elephants under human care.
References
Abeysekara N, Rajapakse RPVJ, Rajakaruna RS (2018) Comparative cross-sectional survey on gastrointestinal parasites of captive, semi-captive, and wild elephants of Sri Lanka. Journal of Threatened Taxa, 10, 11583-11594. http://threatenedtaxa.org/index.php/JoTT/article/view/3406
Abeysinghe KS, Perera ANF, Fernando P (2012) Developing a practical and reliable protocol to assess nematode infections in Asian elephants. Gajah, 37, 22-26.
Abhijith TV, Ashokkumar M, Dencin RT, George C (2018) Gastrointestinal parasites of Asian elephants (Elephas maximus L. 1798) in south Wayanad forest division, Kerala, India. Journal of Parasitic Diseases, 42, 382-390. https://link.springer.com/article/10.1007/s12639-018-1012-0
Baines L, Morgan ER, Ofthile M, Evans K (2015) Occurrence and seasonality of internal parasite infection in elephants, Loxodonta africana, in the Okavango Delta, Botswana. International Journal for Parasitology: Parasites and Wildlife, 4, 43-48.
Chel HM, Iwaki T, Hmoon MM, Thaw YN, Soe NC, Win SY, Bawm S, Htun LL, Win MM, Oo ZM, Masum MA, Ichii O, Nakao R, Nonaka N, Katakura K (2020) Morphological and molecular identification of cyathostomine gastrointestinal nematodes of Murshida and Quilonia species from Asian elephants in Myanmar. International Journal for Parasitology: Parasites and Wildlife, 11, 294-301.
Coe M (1972) Defaecation by African elephants (Loxodonta africana africana (Blumenbach)). East African Wildlife Journal, 10, 165-174.
Fowler ME, Mikota SK (2006) Biology, Medicine, and Surgery of Elephants. Iowa, USA, Blackwell Publishing.
Hackenberger MK (1987). Diet digestibilities and ingesta transit times of captive Asian (Elephas maximus) and African elephants (Loxodonta africana). Guelph, University of Guelph. MSC Thesis.
Hing S, Othman N, Nathan SKSS, Fox M, Fisher M, Goossens B (2013) First parasitological survey of endangered Bornean elephants Elephas maximus borneensis. Endangered Species Research, 21, 223-230. http://www.int-res.com/abstracts/esr/v21/n3/p223-230/
Kingori E, Obanda V, Chiyo PI, Soriguer RC, Morrondo P, Angelone S (2020) Patterns of helminth infection in Kenyan elephant populations. Parasites & Vectors, 13, 145.
Kinsella JM, Deem SL, Blake S, Freeman A (2004) Endoparasites of African Forest Elephants (Loxodonta africana cyclotis) from the Republic of Congo and Central African Republic. Comparative Parasitology, 71, 104-110.
Leopardi S, Keratimanochaya T, Solmi F, Roberts J (2013). Estimation of a linear model capable to predict age of Asian elephants (Elephas maximus indicus) using dung bolus circumference. Proceedings of the International Conference on Diseases of Zoo and Wild Animals, Vienna, Austria.
Lynsdale CL, Franco dos Santos DJ, Hayward AD, Mar KU, Htut W, Aung HH, Soe AT, Lummaa V (2015) A standardised faecal collection protocol for intestinal helminth egg counts in Asian elephants, Elephas maximus. International Journal for Parasitology: Parasites and Wildlife, 4, 307-315. http://www.sciencedirect.com/science/article/pii/S2213224415300031
Lynsdale CL, Mumby HS, Hayward AD, Mar KU, Lummaa V (2017) Parasite-associated mortality in a long-lived mammal: Variation with host age, sex, and reproduction. Ecology and Evolution, 7, 10904-10915.
Morrison TA, Chiyo PI, Moss CJ, Alberts SC (2005) Measures of dung bolus size for known-age African elephants (Loxodonta africana): implications for age estimation. Journal of Zoology, 266, 89-94.
Nishanth B, Srinivasan SR, Jayathangaraj MG, Sridhar R (2012) Incidence of endoparasitism in free-ranging elephants of Tamil Nadu State. Tamilnadu Journal of Veterinary & Animal Sciences, 8, 171-173.
Obanda V, Iwaki T, Mutinda NM, Gakuya F (2011) Gastrointestinal parasites and associated pathological lesions in starving free-ranging African elephants. South African Journal of Wildlife Research, 41, 167-172.
Punya MS, Shyma VH, Reshnu VC, Vijayakumar K, Vinodkumar K, Ambily R, Zachariah A (2021) Gastrointestinal parasites of captive Asian elephants in Kerala. Journal of Veterinary and Animal Sciences, 52, 312-315.
Ratnasooriya WD, Molligoda PS, Molligoda WHM, Fernando SBU, Premakumara GAS (1994) Absence of synchronization either in defaecation or urination of the Sri Lankan elephant (Elephas maximus maximus) in captivity. Ceylon Journal of Science, 23, 47-51.
Rees PA (1982) Gross assimilation efficiency and food passage time in the African elephant. African Journal of Ecology, 20, 193-198.
Schiffmann C, Hatt JM, Hoby S, Codron D, Clauss M (2019) Elephant body mass cyclicity suggests effect of molar progression on chewing efficiency. Mammalian Biology, 96, 81-86.
Schiffmann C, Schiffmann L, Bonillo J, Blukeviciute I, Gozalbes Aparicio E, Paniagua J, Ribera G, Ruiz M, Torro M, Clauss M (2023) A simple approach to monitor faecal particle size in the Asian elephant - A proof of concept study. Gajah, 56, 30-35.
Thewarage LD, Dissanayake DSB, Perera US, Bandara AT, Perera BVP, Wickramasinghe S, Rajapakse RPVJ (2020) Morphology and molecular characterization of Parabronema smithii (Cobbold, 1882) (Nematoda: Habronematidae) from wild Asian elephant (Elephas maximus maximus) of Sri Lanka. Acta Parasitologica, 65, 504-517.
Vanitha V, Thiyagesan K, Baskaran N (2011) Prevalence of intestinal parasites among captive Asian Elephants Elephas maximus: effect of season, host demography, and management systems in Tamil Nadu, India. Journal of Threatened Taxa, 3, 1527-1534. http://threatenedtaxa.org/ZooPrintJournal/2011/February/vanitha.htm
Vimalraj PG, Jayathangaraj MG (2013) Endoparasitic infections in free-ranging Asiatic elephants of Mudumalai and Anamalai Wildlife Sanctuary. Journal of Parasitic Diseases, 39, 474-476.