Gastrointestinal parasites of domesticated and Feral Horses (Equus Caballus) in Sri Lanka

Horses are not native to Sri Lanka. They are imported from neighbouring countries to be used for police work, sporting or riding and esthetic purposes. An isolated population of about 500 feral horses lives in the Delft Island in northern Sri Lanka. These feral horses served hundred years for western conquests and when they left Sri Lanka, horses were left behind in the Delft Island. There are no records of gastrointestinal (GI) parasites of horses in Sri Lanka and the present study was carried out to determine the GI parasites in the domesticated (free grazing and stabled) and feral horses. Fresh faecal samples were collected from horses and analysed qualitatively and quantitatively to determine the types of GI parasites and their prevalence and intensity. Qualitative analyses using direct saline and iodine mounts, simple test tube flotation, Sheather’s modified sucrose flotation and sedimentation technique were carried out followed by McMaster counting technique for the positive samples. Identification of parasites involved morphological, morphometric and molecular methods. A total of 73 horses were sampled. All the feral horses (n=14) were infected. Among the domesticated horses, free grazers had a significantly higher prevalence of GI infections (46.7%) than the stabled ones (18.2%; Chi square test χ2 = 4.787, df = 1, p = 0.029). There was no significant difference between helminth and protozoan infections among the three groups of horses (Chi square test, χ2 = 1.453, df = 2, p = 0.484). Six species of parasites: Anoplocephala sp., Parascaris equorum, Strongylus sp. Isospora sp. Entamoeba sp. and Giardia sp. were recorded. Strongylus infections were recorded in all the feral horses with a high intensity but not in any of the domesticated animals. Strongylus is a highly pathogenic and the most damaging parasite of horses worldwide. It is important to investigate whether Strongylus infection is responsible for the high mortality recorded in the feral horses in the Delft Island especially because the Department of Wildlife Conservation is to declare Delft Island a National Park to conserve the feral horses

Coprological survey of gastrointestinal parasites of mammals in Dehiwala National Zoological Gardens, Sri Lanka

A cross sectional, coprological survey on gastrointestinal (GI) parasites of captive mammals in the Dehiwala National Zoological Gardens was carried out in 2014. Fresh faecal samples from all the mammal species belonging to nine orders: Primates, Carnivora, Perissodactyla, Artiodactyla, Proboscidea, Erinaceomorpha, Lagomorpha, Rodentia and Diprotodontia were analyzed. Intensity of parasite infections was determined using the McMaster technique. Of the 70 samples, 44 (62.9%) were positive for one or more GI parasites. A total of 13 types of GI parasite eggs, cysts and/or oocysts of Trichuris sp., Strongyloides sp., Toxocara sp., Spirometra sp., Moniezia sp., Nematodirus sp., Giardia sp., Blastocystis sp., Balantidium sp., Entamoeba spp., strongyle type eggs, hookworm, and coccidian oocyts were observed. The most common stage was strongyle type egg (17.1%) followed by cysts of Entamoeba spp. (14.3%). Of the infected individuals, 25% had mixed infections. A higher prevalence of helminths (81.8%) compared to protozoans (47.7%) was observed but this difference was not statistically significant (Chi square test; p&gt;0.05). There was no significant difference in the prevalence of infection among the captive bred, imported or wild caught individuals (Chi square test; p&gt;0.05). Mammals of seven orders were infected with GI parasites but lagomorphs and diprotodonts did not have any parasites. Among the herbivores, strongyle type, Moneizia, Entamoeba and coccidian infections were common while Nematodirus sp. in a porcupine and Spirometra sp. in a flying squirrel were rare. Common parasites of carnivores were, Toxocara and Entamoeba but Blastocystis sp. in coati was a rare infection. Trichuris and Giardia infections were common in Primates. High worm burden was evidenced in silver leaf monkey, Hamadryas baboon, African lion, black rhino, pony, porcupine and flying squirrel. Although regular deworming is carried out, results of this survey highlight the importance of faecal analysis before administering deworming and applying a more targeted approach to manage the pathogenic species. This study provides baseline data on the GI parasites of all the mammal orders at Dehiwala Zoological Gardens.</p

Comparative mitogenomics of the zoonotic parasite 'Echinostoma revolutum' resolves taxonomic relationships within the 'E. revolutum' species group and the Echinostomata (Platyhelminthes: Digenea)

The complete mitochondrial sequence of 17,030 bp was obtained from Echinostoma revolutum and characterized with those of previously reported members of the superfamily Echinostomatoidea, ie., 6 echinostomatids, one echinochasmid, 5 fasciolids, one himasthlid and two cyclocoelids. Relationship within suborders and between superfamilies, such as Echinostomata, Pronocephalata, Troglotremata, Opisthorchiata, and Xiphiditata, are also considered. It contained 12 protein-coding, two ribosomal RNA, 22 transfer RNA genes, and a tandem repetitive consisting non-coding region (NCR). The gene order, one way-positive transcription, the absence of atp8 and the overlapped region by 40 bp between nad4L and nad4 genes were similar as in common trematodes. The NCR located between tRNAGlu (trnE) and cox3, contained 11, long (LRUs) and short repeat units (SRUs) (7 LRUs of 317 bp, 4 SRUs of 207 bp each), and an internal spacer sequence between LRU7 and SRU4) specifying high level-polymorphism. Special DHU-arm missing tRNAs for Serine were found for both, tRNAS1(AGN) and tRNAS2(UCN). E. revolutum indicated the lowest divergence rate to E. miyagawai and the highest to Tracheophilus cymbius and Echinochasmus japonicus.The usage of ATG/GTG start and TAG/TAA stop codons, the AT composition bias, the negative AT-skewness, and the most for Phe/Leu/Val and the least for Arg/Asn/Asp codons were noted. Topology indicated the monophyletic position of E. revolutum to E. miyagawai. Monophyly of Echinostomatidae and Fasciolidae was clearly solved with respect to Echinochasmidae, Himasthlidae and Cyclocoelidae which were rendered paraphyletic in the suborder Echinostomata