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EYE PROBLEMS IN AQUATIC
TURTLES
By
Nadine Gill
One of the most common conditions we have
reported from keepers of aquatic turtles is that the eyes of their terrapin
have swollen or closed. These symptoms can be the result of several conditions,
and a prompt diagnosis can allow for effective treatment to begin without
delay. Early intervention is critical because, as sight feeders, aquatic
turtles will stop eating once their eyes are closed.
Pet stores commonly sell vitamin A drops
that claim to cure vitamin A deficiencies and eye infections. These products
are ineffective in resolving either of these conditions, and though they may
cause no direct harm, they delay proper diagnosis and treatment.
In order to accurately diagnosis the cause
of a swollen or closed eye, a veterinarian experienced in treating chelonians
will not only rely on clinical signs, but will also ask the owner about the
turtle's history, including its dietary regime and the environmental conditions
in which it is maintained. It is too often the case, however, that these
factors are not even considered, and that the swollen or infected eye is
incorrectly diagnosed as the result of a vitamin A deficiency.
Vitamin A deficiency is one possible cause
for an eye infection, and is the result of diets that rely on foods deficient
in beta carotene or preformed vitamin A, such as insects, ant eggs, dried
shrimp and other poorly formulated commercial foods. This deficiency is
unlikely to develop, however, when a turtle's diet contains a fortified
commercial turtle food, such as Reptomin, vegetation and leafy salad greens
rich in beta-carotene (the precursor to vitamin A), or has been provided with a
multivitamin supplement once a week.
When a turtle does become Vitamin A
deficient, it causes changes in the epithelial tissues that begin to breakdown
and become predisposed to infection. Early signs include eyelid edema, as the
tear secreting glands swell outward and cellular debris accumulates underneath
the eyelids, and these symptoms will progress until the eyelid remains closed
or even appears to be fused. Respiratory symptoms may also be present, and
renal, pancreatic, and gastrointestinal epithelium may be affected as well. In
the early stages, correcting the diet to include vitamin A may successfully
treat the deficiency, but more advanced cases may require vitamin A injections.
Secondary bacterial and fungal infection
can also be present, as opportunistic pathogens attack the compromised
epithelial barriers, and it is important to note that any such infection will
need to be treated. Simply correcting the deficiency will not resolve a
resulting infection. Eye infections can usually be successfully treated with
antibiotic eye drops or ointment, but if the particular microorganism is
resistant to the antibiotic used, or the infection has become systemic, more
specific treatment would obviously be required. The sooner a vitamin A
deficiency is corrected and any secondary infections treated, the better the
chances for a full and more rapid recovery.
Vitamin A deficiency is a serious condition
that requires prompt medical intervention and dietary modification. If it is
determined, however, that the turtle's requirement for vitamin A has been met
through the provision of beta carotene rich foods or a multivitamin supplement,
other possible causes for eye conditions should be considered.
- Ear abscesses can also cause the eyes to
become swollen and shut. These abscesses can be bilateral or may affect only
one ear. Surgery to drain the abscess followed by a course of antibiotics is
necessary to treat the infection.
- Trauma injuries can result in swollen and
closed eyes. Having adequate surface area for turtles to dive and swim freely
will prevent the lacerations and bruising that frequently occur in small
aquariums. Rocks and tank decorations with sharp edges should be avoided, as
they can cause injuries and also leave the affected sites open to infection.
- Dehydration of aquatic turtles can result
in irritated, closed and infected eyes. Hatchlings that have overwintered in
the nest may sometimes be found with swollen and closed eyes. Placing the
turtle in water and using lubricating ophthalmic drops may relieve a simple
irritation caused by dehydrated eye tissue, but a veterinary examination is
recommended as a precaution, even if a good response is noted, to rule out
other possibilities.
- Sand or other particulate matter in the eye
will cause irritation and swelling that can lead to more serious problems,
including infections. If you see your turtle rubbing its eyes with the backs of
its fore claws, this possibility needs to be ruled out before a possible
condition worsens.
When the exact cause for the condition is
diagnosed, addressing the following aspects of husbandry will support your
turtle's recovery and will greatly reduce the chance of it developing eye
problems (as well as other illnesses) in the future. Poor water quality is
often the cause of eye and skin infections. Husbandry related infections could
be easily prevented by providing adequate water volume for the number of
turtles maintained and to purchase equipment powerful enough for effective
filtration.
Introduction of new turtles, especially
those acquired from pet stores (where improper handling is common), can result
in cross infections. I personally quarantine any new reptile for at least two
years, particularly if it came from a pet store or its background is unknown.
Some viruses can remain dormant much longer than that, so there is still a
possibility for cross infection, albeit very slight, even after that length of
time. Improper handling can lead to cross infection between turtles. Simply
washing your hands well with an antibacterial soap will prevent most cross
infections, but it is highly recommended to use a solution including
chlorhexidine or povidone iodine after handling turtles suffering from illness
or infection or those that have a high probability of carrying potential
pathogens.
Most eye problems we have reported to us
are not related to vitamin A deficiency, and could have been easily avoided
through the provision of better environmental conditions, precautionary
quarantine, and better handling procedures in large and mixed collections. Following these guidelines will greatly
reduce the chances that your turtle will ever suffer from these all too common,
but easy to prevent eye conditions.
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