Dr. Mattia Bielli, Med. Vet. (Novara, Italy)
In recent years we are facing a progressive declining of most of the wild animal populations. Reptiles and amphibians have suffered for a long time for being considered "inferior vertebrates" and for that reason they had received less attention by scientists involved in conservation compared to the so called "superior vertebrates".
In our day things are slowly changing and, as an example, the important role of Amphibians as ecological indicators is today recognized1.
Among reptiles, turtles and tortoises are the two most popular groups and some studies have been carried on to cover different aspects of their ecology and conservation. The impact of diseases on wild animals can be really dangerous and the Mycoplasma epidemic in the Sonoran and Mojave deserts or the fibropapillomatosis in marine turtles are well known examples.
Moreover, most of the Chelonian populations have been reduced in size and are endangered; in these conditions a disease outbreak is likely to be disastrous.
To prevent epidemics that could threaten the remaining populations is of paramount importance to collect as much data as possible on the existing individuals; such information will be used as a baseline to enable scientists to better face future outbreaks in the wild.
Surprisingly very little data is known on the health status of wild populations in Europe 5,6 and, together with many other topics, our knowledge on infectious diseases of free ranging Chelonians should be enhanced.
Despite the tremendous improvements in herpetological medicine in the last years, medical aspects are too often neglected and underestimate when approaching conservation plans for endangered reptiles and amphibians4.
Regardless to the approach chosen to maintain biological diversity, manipulative or conservative, the main health hazards in field studies are:
• Various injuries
• Spreading of pathogens within the population and introducing new pathogens (or more virulent strains) through reintroduction of new specimens.
For proper handling stress must be minimized and every procedure should be planned well in advance in a standardized manner. People working in field situations should be trained for reasonable periods before being allowed to manipulate the animals.
The risk of contamination is lowered wearing disposable gloves and to change shoes or boots when moving from different sites. Since urination is common when handling terrestrial tortoises and water loss can be life threatening in arid habitats, fluid replacement should be considered2.
Thanks to the possibility to work on captive chelonians, the herpetological medicine have developed various techniques and methods that can readily be applied on wild populations.
Those veterinarians experienced in herpetological medicine are usually well trained and uniquely qualified to make accurate evaluations to distinguish between a true pathological condition and other physiological or seasonal changes.
Furthermore the veterinarian's knowledge of anatomy, physiology and pharmacology can be of invaluable assistance in field research4. Specific veterinary research should cover all the aspects of health management such as:
• Establish normal blood values (hematological and biochemical) in different sex, season, area….
• Check gastro-intestinal and ecto-parasite infections
• Screen for main pathogens (herpes, irido, picorna-virus, mycoplasma)
• Screen for toxic contaminants
• Investigate fecal content to identify food preference
• Monitor reproductive activity
Not only can this data improve our knowledge of the health status of free ranging chelonians but it can also be used to better manage captive breeding programs.
Since most of Chelonians species in the wild are seriously threatened, captive breeding programs are a viable option for conservation and we must start to prepare healthy stocks for future reintroduction.
In order to avoid introducing new diseases in the wild, we should start thinking of some programs with same sort of certification for the breeding activity where all the reproductive individuals have to be tested for the main diseases according to our most updated knowledge and techniques.
Thought is beyond the purpose of this work, the certification should also apply to the origin of the specimens trying to establish groups of animals coming from the same region. Cooperation among institutions at every level (CITES, IUCN, Environment State Agencies, Societies, Zoological collections, Private Centers, Universities….) and among professional figures (veterinarians, naturalists, ecologists….) is the key factor to achieve the best results in Chelonian conservation worldwide.
1 KB Beckmen, CL Lieske, JE Murphy, A Schotthoefer, LB Johnson, CM Johnson, R Cole, VR Beaseley, Amphibians as monitors of ecosystem health 2001 ARAV Proc p.51-52
2 KH Berry, EK Spangenberg, BL Homer, ER Jacobson, Deaths of Desert Tortoises following periods of drought and research manipulation, Chel.Cons.Biol 2002 4(2): 436-448
3 J.Flanagan Chapter 3: Diseases and health considerations In: Turtle Conservation, M.W.Klemens ed. Smithsonian Institute Press 2000 Washington
4 J.L.Jarchow The Veterinarian's role in Herpetological field studies 2004 7th Int. Symp. on Pathol. and Med. of Reptiles and Amphibians
5 R.E.Marshang, R.M.Schneider Detection of antibodies against chelonid viruses in wild-caught spur-tighed tortoises, Testudo graeca, in Turkey 2002 ARAV Proc. p. 95
6 K.A.Mathes, E.R. Jacobson, S.Blahak, D.R.Braun, I.M.Shumacher, B.Fertard Mycoplasma and Herpesvirus detection in European terrestrial Tortoises in Franca and Morocco 2001 8th ARAV Proc. p.97