Unless your turtle is a softshell turtle,
turtle's shell should be nice and hard and solid.
This is true for box turtles, tortoises, and water turtles, equally.
Knocking on the shell should feel solid, pushing on the shell should
not create any dents, and no soft patches should be found on the shell.
The most common cause of a soft shell is insufficient Calcium and/or
insufficient Vitamin D3. It is beyond the scope of this article to explain
the whole Calcium/Vitamin D3 metabolism, but here is a short overview:
* Calcium is obtained through the diet.
* Two factors affect how well this calcium can be used by the turtle:
a) the availability of vitamin D3, which is used to metabolize calcium and
b) the calcium/phosphor ratio, which determines how much of the calcium
can be absorbed into the body. Good sources have twice the amount of
calcium than phosphor. Bad sources have equal or more amounts of
* Vitamin D3 is mostly generated by the body in a complex process that requires
using sunlight. An artificial UVB source is much weaker, but can be an adequate substitute.
Dietary D3 can be found in animal products. Or in vitamin supplements.
* Good calcium foods include all green, leafe vegetables.
* Most turtles love to chew on cuttle fish bone. This pretty much guarantees
that they get enough calcium.
* Most commercial turtle foods now supplement Calcium and Vitamin D3.
If your turtle has a soft shell and is otherwise healthy, you must
provide him with enough calcium and a way to synthesize Vitamin D3.
(Refer to the care sheet on feeding turtles for more information.)
If your turtle has other problems, consult a veterinarian who knows and
cares about turtles. If the soft shell is extensive, consider taking the
turtle to a veterinarian for x-rays and evaulation to assess the amount
To give extra calcium, buy "cuttle fish bone" at the pet store.
The turtles like to chew on it, and that will take care of the calcium.
For vitamin D3, you can either let your turtle bask in unfiltered sunlight every
day for at least an hour, or you can install a fluorescent UVB bulb on the
basking area, or you can supplement vitamin D3.
It will take many months
for the turtle to heal. However, if he stops getting worse, you are probably
winning the battle. He will not die of this, if he gets help now. However,
if the disease is far enough advanced, your turtle may be crippled for life.
If he doesn't get help, all his bones will get soft, and that is not very healthy...
For extensive information on the topic of fluorescent reptile lights, vitamin
D3, metabolic bone disease, and a discussion of types of lights, please, read
the following information:
Comprehensive Discussion of Vitamin D3 Issues
Why UVB is Essential
Discussion of Several Reptile Lights
Personal Note 1: I used to recommend supplementation of D3, and I have had excellent results
with it. However, with supplementation there is always the issue of
underdosing and overdosing. These days, some excellent lights are available, and
they should be used for turtles and lizards that do not get exposure to unfiltered
For my Geckos, I use ZooMed's Reptile light and calcium supplementation.
All my box turtles get cuttle fish bones, a healthy diet, and natural sunlight year round.
All my water turtles get cuttle fish bones, a healthy diet, and natural sunlight year round.
For indoor box turtle setups, I double up with an outdoor pen for spring-fall.
In winter I supplement D3.
For indoor water turtle setups, I recommend a reptile light.
Personal Note 2: Cow milk has a lot of calcium, and
even more phosphorus. Do your own thinking...