Tortoises
GENERAL
TORTOISE HUSBANDRY
By Phillippe De
Vosjoli
Photos
and edited by Susan Horton, DVM
Husbandry factors are a common cause of many
of the health problems affecting tortoises. Addressing husbandry
issues is a critical component of the veterinary treatment of
these popular animals.
Tortoises are members of the turtle family Testudinidae.
Because of their mechanical-toy appearance, docility and endearing
faces, tortoises remain among the most popular of all reptile
pets. Thousands of imports and captive-bred tortoises are now sold
annually in the pet trade, often to buyers who are uninformed
about husbandry requirements. As a result, tortoises are among the
reptiles most commonly seen by veterinarians.
Special Features
Tortoises have taken a unique evolutionary path. The normal
defense of flight or aggression adopted by most reptiles has been
replaced by the evolution of armor in the form of a shell. The
tortoise shell (a vertebrate exoskeleton) has a compact rounded
form with a low relative surface-to-volume ratio. What the
implications? The shell offers minimal surface exposure to
predators. Moreover, in terms of thermoregulation, heat once
stored is retained for a long time. A tortoise that has been out
basking may feel warm hours later as it rests in the insulating
confines of its shelter. Because up to 50% of a tortoise's weight
(more in the case of thin animals) can consist of shell that is
mostly skeleton, there are few species in which the effects of a
multifactorial model of herpetoculture can be more easily
observed.
Depending on how tortoises are raised, you will see in the
course of their development differences in shell-to-body ratios
and variations in shell, beak and nail growth. It should come as
no surprise that various deformities and related health problems
are common in captive-raised tortoises.
Selection
If one excludes the small numbers of rarer tortoises bred by
specialists, the tortoise species sold in greatest numbers to the
general public are the African spurred tortoise, the Leopard
tortoise (now bred by the thousands annually) and the Russian
tortoise, which is still imported by the thousands from
Russia
. Smaller numbers of Forest Hingeback tortoises are also imported
for the general pet trade.
As a rule, the smaller species, particularly the Russian and
Greek tortoises, are better choices as pets than the large
tropical species, which will eventually require either outdoor
pens (in warmer areas) or room-sized enclosures and expensive
heating and lighting. Some species of tropical tortoises, such as
the South American red-footed and yellow-footed tortoise, are
especially suited for areas with a high relative humidity (70%+).
Housing
Except for juveniles up to 4" long (which can initially
be raised in tanks 36-48" long), tortoises should be kept in
sizeable pens, at least 12 ft square and preferably 24 ft square
for smaller species. Their need for space makes many species
unsuitable as long-term indoor pets. Larger species, such as
African spurred and leopard tortoises, can exceed 60 pounds (e.g.,
200 pounds for a very large African spurred) and require pens at
least 16' x 8' for smaller animals and 16' x 16' for larger ones.
If kept indoors, these tortoises will require room-sized
enclosures that will be challenging to maintain.
Landscaping outdoor enclosures
All tortoises require shelter in order to feel secure and be
free of the debilitating effects of chronic stress. Many keepers
construct wood shelters for large species. Small dog houses or
half-houses such as the plastic types with a top and snap-on
bottom, can be provided for smaller species.
Other keepers successfully use clay flower pots placed on
their sides and half buried in substrate. In addition, shelter and
shade for savannah species, such as African spurred and Leopard
tortoises, should be provided by shrubs or large grasses.
Tortoises especially prefer shelters that lightly brush along the
top of the carapace (top shell) when entered. The touch likely
simulates that of foliage in the wild and can imitated with
burlap, cloth or plastic, dried foliage or (if not eaten)
artificial plants.
Leopard and Marginated tortoises have a domed shell that
differs from the broad, dorso-ventrally flattened shell of the
Gopher, Russian and African spurred tortoises. The latter are
typically burrowers and ideally should be provided with enough
substrate in which to construct burrows. An alternative is to dig
hollows in the ground and cover them with wooden boards. Burrowing
tortoises will choose to hide under the wood.
Temperature
As with other reptiles, providing the optimal temperature
range for thermo-regulation is critical for the welfare of
tortoises. Failure to provide adequate heat is a key factor in
many diseases of these animals, including acute problems (such as
life-threatening respiratory infections) and chronic disorders
(such as shell deformities).
During warm months with daytime temperatures of greater than
75 degrees F (24 degrees C), tortoises placed in outdoor
thermoregulate without the expense of spotlights and other heating
devices. When housed indoors, tortoises should be offered a
basking site under spotlights that can create a spot temperature
of 85-90 degrees F (30-33 degrees C). All heat sources should be
limited to only a portion of the enclosure. Ideally, both a
thermometer and thermostat should be used to regulate the
temperature at the basking site. The rest of the enclosure should
be maintained at an ambient temperature to allow the tortoise to
thermoregulate by moving between heated and unheated areas.
Outdoors, cooler areas are provided by shade and shelter.
Providing heat for adults of large species of tortoises (as with
other large reptiles) can be problematic and costly. To complicate
matters, failure to provide appropriate cool spots can be fatal to
certain species, such as the rarer Burmese and Bowsprit tortoises,
so reference texts on specific species requirements should always
be consulted when caring for tortoises.
Brumation (Hibernation) for the advanced keeper
Mediterranean species should be allowed to brumate at cooler
temperatures for a few months. In areas of the
U.S.
with mild winters, these species can brumate in an unheated room
of a house. Owners should consult texts that provide information
on techniques to offer these species a cool rest period.
(For more guidelines on brumation, please refer to
"Safer Hibernation and Your Tortoise" by Andy C.
Highfield at www.tortoisetrust.org/articles/safer.html)
Drinking Water
Clean water should be made available at all times in a
shallow water container that allows the tortoise to drink by
tipping its head down. A shallow (less than the height of the
shell) water container needs to be buried in the substrate with
the edge just above the surface or, if its depth is about equal to
the thickness of the tortoise's head, placed on the surface of the
substrate.
Diet
Most tortoises are strict herbivores, and many are primarily
grass-eaters. In a sense, they are reptilian version of horses or
guinea pigs, because they use hindgut fermentation to digest
fiber. In captivity, most tortoises should be allowed to graze on
grasses and weeds whenever possible. In addition, or as an
alternative, various greens such as romaine lettuce, collard
greens, mustard greens and dandelion may be fed routinely.
Tortoises also like vegetables such as green beans, zucchini and
other squashes. Tortoises consider red and orange fruit a treat,
and these can be offered to constitute up to 5-10 % of the diet
for savannah species and 25-30 % of the diet for tropical species
(such as red-footed and Burmese). Mango, papaya, banana,
cantaloupe, strawberries and watermelon are favorites.
The tropical species will eat small amounts of meat and
invertebrates when available and can be offered pinky mice, slugs
and nightcrawlers 3-4 weeks. Small African spurred tortoises kept
outside in
California
relish any snails they can find. Many of the African species are
programmed to eat white objects (calcium-rich bone fragments and
snail shells in their native savannah) and ingest crushed
cuttlebone and other calcium sources or white foreign bodies in
captivity.
Fiber intake is critical for herbivores. All should be fed
fiber sources such as grasses and browse when outdoors and grass
hays (chopped or long-stem) when indoors.
Most diets of fresh graze or produce require
supplementation with calcium, at a level of 1-2% of dry intake.
Additions of calcium carbonate are needed for salads of commercial
produce. Commercial pelleted diets sold in the pet trade have been
fed successfully by some breeders when part of a diet that
includes fresh graze, browse and produce. A potentially serious
problem with commercial pellets is that they have low water
content, and tortoises rely on adequate water intake (from food
and drinking) for renal function. Diets of pellets exclusively
risk dehydration.
Soaking
All tortoises benefit from a weekly soak of 30-60 minutes in
shallow warm water. Many tortoises seem to be hard-wired to drink,
urinate and defecate only when soaked. In these individuals,
failure to drink from a container within a habitat should not be
perceived as a lack of thirst or absence of dehydration. Tortoises
fed dry commercial pellets should be soaked daily. Species from
humid areas (such as red-footed and yellow-footed tortoises)
should be soaked at least once weekly and also have water
available in their habitats. All hatchings, as well as sick
tortoises, should be soaked daily. Rescues, new imports and
dehydrated patients passing visible white precipitated urates
benefit from soaks twice daily.
Thank you from
Chicago
Exotics
Animal
Hospital
. Please call if you
have any questions 847-329-8709.
See www.Chelonia.org
for lots of good information
