Gastrointestinal parasites in snakes: a survey

Aim. Anyone who tries to approach the reptile’s parasitology in a scientific perspective, will become immediately aware about the scarcity and fragmentary nature of the available information that in some cases are even misleading (Seghetti M & Traversa D., 2006, Atti III Conv. Naz. SIVSANC, Teramo 5-6 maggio, 39-41). If the attention is focused on the gastrointestinal parasites of snakes, the lack of scientific reports is even more pronounced. Despite their wide distribution in Italy, veterinary expertise in this field is still scarce and incomplete. The laboratory practice, usually reserved to a small group of experts, is not commonly performed. Up to now few attempts there have been made to study the prevalence of different parasites; in many cases the poor information available are not comparable because the survey are performed in different countries, on different species of snakes, with different purposes and using different laboratory techniques. The lack of iconographic support, with the frequent interference due to parasites of preys, does not facilitate the coprological diagnosis, and may lead to false positives (Jacobson E.R., 1983, Current Vet. Therapy, 8:599-606). This work was done on captivity snakes with the aim to identify and to assess the prevalences of their gastrointestinal parasites. Material and Methods. The survey was carried out from January 2009 to March 2010. A total of 90 snakes breeded, marketed and held as “pets” were screened: 82 from Boidae family and 8 from Colubridae family. All animals were kept under the terms of existing legislation. Individual fresh fecal samples were collected in the context of herpetological fairs, at breeding facilities or at the owners and kept at 4°C until they were processed; 79 (87.7%) animals was born in captivity, the others were captured from various location of the world. The ophids were housed individually at temperature between 28-30°C, in separated plastic or glass boxes and were fed by small live rodents (mouse or rat). The substrate used was mainly paper or paperboard. No snake was treated against endoparasites. The fecal examination was carried out by fecal flotation in saturated sugar-salt solution (specific gravity 1.3). Parasite eggs were identified by their morphology and morphometric characteristics. In order to better understand the results of coprological examinations of snakes, when possible, fecal pools from rats and mouse were collected. Results. All fecal samples were of normal consistency and color; 49 (54.4%) were seemingly positive, but only 8 animals (1 Boa constrictor constrictor, 1 Boa constrictor imperator, 1 Corallus caninus, 1 Elaphe guttata, 1 Epicrates cenchria cenchria, 2 Morelia viridis, 1 Python regius) were positive for one or more specific parasites of reptiles as strongyles (7,8%), Strongyloides spp. or Rhabdias spp. (3.3%), sarcosporidia (1,1%) and cestodes (1,1%). The higher prevalences, 18,2% (2/11) were found in wild-caught snakes group; in born captive group prevalences were 6,8% (5/73). In 46 (51%) samples pseudoparasites were found: rodent’s mites eggs 36 (40%), rodent’s pinworms 22 (24,4%) and rodent’s cestodes 11 (12,2%). Prevalence of coccidia was 26,7%. Coprological examination of rodents’ fecal pools has highlighted the same eggs/oocists found in linked snakes, supporting the diagnosis of pseudoparasitism. Conclusions. This preliminary work confirm the frequent presence of pseudoparasites in captivity snake, with low prevalence of specific parasites. Gastrointestinal parasites are not a serious problem for these animals, considering that pathogens able to survive and replicate, indoors and under controlled conditions, without an intermediate host, are very few (Radhakrishnan S.P. et al, 2009, Zoo Biology, 28:253-258). In wild-caught snake, parasite prevalence can be high and specific parasite, in stressfull conditions as captivity, can become a serious problem, compromising the reptile’s welfare (Kiel J.L., 19...