What are you using for heating and lighting? Does your tortoise have a UV bulb? Do you know your temperatures?
Madkins007 said:To those advocating electrolytic solution soaks-
Electrolyte solutions are basically salt water with a dash of sugar used to treat dehydration. There is little calcium in a typical electrolytic solution- because calcium does not dissolve well in water. Adding calcium to water does not actually make a calcium solution that would be absorbed through the skin in a soak, and if it is drank, the concentration of calcium in the water would not be significant.
The nutritional label for powdered Pediolyte says: "Sodium, mEq: 10.6; Potassium, mEq: 4.7; Chloride, mEq: 8.3; Dextrose, g: 5.7; Calories: 23" (http://pedialyte.com/products/powder-packs). Translated, that means "salt, salt, salt, and sugar." (For more complete nutritional info, try http://nutritiondata.self.com/facts/baby-foods/7608/2). Notice that is it not a significant source of most minerals or vitamins and its primary benefit is to help dehydration, not calcium-related medical issues, like this.
This tortoise seems to be suffering from a significant case of Nutritional Secondary Hyperparathyroidism, and the recommended treatment involves injected calcium, vitamin D3, and supportive cares. When the shell is soft in an adult tortoise, it is far past the 'add more calcium to the diet' or 'try warm soaks' stage- the vet should examine the calcium levels in the blood, and if needed, offer calcium injections spread over time, along with other specific cares.
Adding baby food or vitamins and minerals to soak water may help in many health situations. Warm water soaks trigger urination and that triggers drinking- which means they get some nutrients. There is also a small amount of water absorption through the cloaca, and some nutrients MAY be absorbed as well, but they would have to be very tiny particles and calcium is a very big particle most of the time. There is a widely held belief that they will absorb some of the stuff through the skin, but that is simply not true. It would be true for amphibians and fish, but reptile skin is waterproof (a fact listed in nearly every definition of 'reptile' you can find.)
In other words- soaks are a great home treatment for many issues, and may have a good preventative aspect, but in a situation like this they are not much more than putting a Band-aid on a torn-off leg.