Posted: Sat Feb 23, 2008 12:03 am
I think fungus has invaded areas on the shell that were damaged either from scraping against something or from poor water quality and not basking enough under good light. That's why there are patches of bright white on the shell. At the bottom of this post is a very good treatment for this problem from a well-respected site (Austin's Turtle Page). I used it on my turtle and it works. The main medicine, Sylvadene (also know as silver sulfadiazine or SSD cream) is only available from vets.
Note, however, that the problem will not be permanently cured until the underlying causes are corrected. For a healthy shell, it's essential that a turtle get to bask frequently under good quality light. When he basks, he has to dry out completely, top and bottom. If he doesn't get to dry off infections like fungus and bacteria can take hold. And the light must contain good UVB. If you're not sure about the basking and light after reading up on it on here, please just ask away and we'll try to clarify.
Here's the treatment:
"Listed below is a regimen that I have followed in treating shell problems and has yielded great results. Keep in mind that shell injuries will take months and sometimes years to get back to looking normal if the possibility exists. It takes weeks before the shell will look like it's getting better. While treating, you are not looking for signs of healing or repair - you are looking to ensure that it is not spreading.
Clean infected areas thoroughly with a strong, undiluted betadine, iodine or Nolvasan solution. Let the turtle air dry in a warm setting for about 45 minutes.
Apply a generous coating of Silvadene cream. Work into problem areas.
Leave the turtle dry and warm, ensuring that you do not over-heat, for 18-21 hours each day.
The next day, scrub entire shell with a one of the previously mentioned solutions, using a soft-bristled toothbrush
Place them into fresh, clean water. Let them swim, drink and eat for approximately 1 - 1 ½ hours.
Repeat procedure from Step 1.
This treatment performed daily or twice daily, depending on your time allocation, has been successful in as few as 8-10 days but in more extreme cases can take a few weeks. It is difficult to tell success right away, so it is often discouraging. It is, however, quite effective and you will begin to see small improvement (in most cases) in only a few weeks."
SpotsMama