box turtle shell

Question
I'm worried.  My box turtle's carapace is soft.  Does this mean it might be ill?  It is six years old.  I have cared for it since it was a few weeks old.  It lives in a indoor tank with substrate, a hide log, and a uv lamp.  I feed it twice a week, mainly vegtables.  Occasionally, I will feed it meat or a piece of fruit as a treat.  I make sure to give it fresh drinking water every day.  I put it a shallow bath every two weeks.  He is active and still has an appetite.  His plastron is strong.

Answer
Soft shells is the result of a calcium problem. This can mean that there is not much calcium in the diet to start with, or that there is too much phosphorous in the diet, or that there is not enough vitamin D3 (available in most meat, unfiltered sunlight, UVB bulbs, and supplements and prepared foods.

We usually talk about calcium (Ca) in relation to phosphorous (P)- we call it the Ca:P ratio, and we want a Ca:p of about 3:1- 3 parts calcium for every part phosphorous. If the ratio is bad, then the extra phosphorous makes the bones softer- but too much calcium makes them brittle.

Vitamin D3 is critical in the how the body actually uses the calcium- without it, all of the calcium in the world cannot be used.

So, the question is how is the Ca:P and D3? D3 first.

Does your turtle get good sunshine, unfiltered by glass or plastic, or do you use a UVB bulb that is younger than 6 months? (UVB bulbs stop emitting UVB after about 6 months.) Does your turtle get a supply of meat, insects, or meat-based pet food?

Lets look at diet. Wild Box Turtles do not eat hardly any fruit, not much veggies, some greens, some mushrooms, and about 75% bugs, insects, worms, arthropods, carrion, etc.

This is not going to be a quick thing to fix- it will take a few months. Try http://www.tortoisetrust.org and http://www.boxturtlesite.info for ideas on basic cares- temps, humidity, housing, etc.

As for diet, try this:

1/3rd insects, crickets, worms, snails, etc.- live, or well-preserved (not the cheap stuff)

1/3rd well-soaked cat kibble (weight maintenance formula), canned box turtle diet, hard boiled egg and shell, etc.

1/3rd salad- dark leafy greens, shredded carrots, mushrooms, bean sprouts, and an occasional strawberry.

Add a sprinkle of calcium carbonate powder (Rep-Cal) and reptile multi-vitamins a couple times a week.

Get and use a good UVB bulb to help further, and just take good general care for the next year.

Good luck!