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Worming difficult to handle tortoises and turtles
Andy C. Highfield
Tortoises and turtles, especially if recently
imported or purchased, may have very large parasite burdens. It
is essential in such cases that a thorough fecal examination be
carried out to determine the nature and severity of the problem.
Even isolated animals that have been maintained in captivity
for years can acquire high concentrations of such parasites, though
constant contamination of their habitat via fecal material, and
subsequent ingestion of worm ova. Depending upon the class and life-cycle
of the parasites involved, infection may also occur as a result
of contaminated food items. Pathological and deleterious effects are not
always obvious. Some nematodes can be seen with the naked eye, and almost
all tortoise keepers will see some nematodes in the feces of their tortoises at
some stage or other. Just because no 'worms' are visible, however, does
not indicate that your tortoise is free of the problem.
The only way to determine this is to have fecal samples regularly
examined under the microscope. There are over 1,000 identified species
of nematode that are known to affect reptiles.
They vary in size from a few millimeters to over 30 cm. Most occur in the intestinal
tract, though some can migrate into the
lungs and throat, where the consequences can be very serious indeed. High concentrations
of nematodes in the gut can also cause very severe health problems,
even though the symptoms of such a condition may not be at all obvious
to the keeper before serious damage results.
The only sensible course of
action is to have periodic fecal exams carried out, and to treat
the problem in the early stages, before high concentrations of the
parasites build up.
One preparation often used
with good results against many common nematodes is Panacur (fenbendazole).
It is normally delivered as a liquid suspension, via stomach tube.
A typical dosing regime is 50-100 mg per Kg, repeated in two weeks
(Stein, 1996). In most cases, this mode of delivery is both
safe and practicable. It is important to note, however, that Panacur
is not effective against all classes or species of nematode
parasite, and that only laboratory assay will determine if it is
an appropriate drug to be used in the first place, or whether or
not, following use, it has proved effective. With certain species
of tortoise, however, delivering preparations by stomach tube can
prove seriously problematic. Species such as Kinixys homeana
and Kinixys erosa are especially difficult to handle, as
they have a very narrow aperture between the carapace and plastron,
are often extremely nervous, and can withdraw their heads back extensively
with great strength - making handling potentially very traumatic
and stressful. Other species where problems are often reported concrning
oral administration include Leopard tortoises (Geochelone pardalis)
and African Spurred tortoises (Geochelone sulcata). Both
of these species are enormously strong, and have been know to resist
the most expert and determined efforts to utilise a stomach tube.
In such situations, some veterinarians
will recommend the use of an injectable antiparasitic such as Levamisole
(Tramisol) or Ivermectin (Ivomec). The former, Levamisole, has been
used in chelonians, but there are serious reservations as to its
effectiveness. The
latter, Ivermectin, has proved consistently fatal in chelonia and
should not be used under any circumstances.
One possible alternative in
these circumstances is to utilize the paste form of Panacur and
deliver this orally, disguised on food. Clearly this will only be
effective in the animal is still feeding, and there are undoubted
problems in ensuring accuracy of dose. This is further complicated
by the fact that the preparation is sold at different concentrations
(strengths) in different countries. You should discuss this with
your veterinarian, and calculate a suitable dose, based upon locally
available products.
It is by no means a universal
treatment or answer to the issue of nematode infestations in tortoises,
but does provide a viable solution in many cases where the only
apparent alternative may be to resort to anaesthesia, or where great
stress and even injury can result as a consequence of the struggle
necessary to administer the stomach tube.
References:
Stein, G. (1996) In
Reptile Medicine and Surgery (edited by Mader), W.B. Saunders
and Company.
We would like to thank
Chris Tabaka, DVM for pointing out serious typographical and other
factual errors in the original version of this advice. We are indebted
to him for his observations. It is unfortunate, however, that he
did not do so sooner during the period when he served as Tortoise
Trust veterinary adviser and was personally responsible for reviewing
and ensuring the accuracy of all material placed on the website.
The original, erroneous text remained on the site for a full two
years during his tenure as our veterinary adviser.
It is our policy to immediately update
and correct any errors that may occur on our site. We invite anyone
who feels they have detected such errors to contact us with their
comments, and we guarantee that in all cases where errors are bought
to our attention corrective action will follow without delay.
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