From time to time you may experience problems with your snails. Very little is known about what these illnesses are, what causes them, and even less is known about treatments. Unfortunately it seems more time is spent on increasingly more ingenious ways to kill them.
Because of this, the following information is a mix of whatever research is possible and available, theory and hypothesis, logical thinking and the result of various discussions with a large group of snail owners. It is with the help of the community at large, that these problems can at least be documented. Where possible I have tried to link to example incidents.
Hopefully, we can find some effective solutions to the majority of these problems but for now I'm afraid you'll have to be content with various suggestions and discussion.
Not Eating Calcium
If your snail isn't eating cuttlefish there are a few things you can do.
The first method is to wean your snail onto it. In a lot of cases, particularly wild-caught specimens, they simply haven't figured out that cuttlefish means calcium. Try crushing the cuttlefish and sprinkling it over other food, perhaps even covering some of the substrate with it. The snails will eat the food, discover the cuttlefish since they can't separate the two. Then you can put pieces of cuttlefish in dusted with cuttlefish powder. Your snails will recognise the powder and in doing so discover the cuttlefish. In most cases this works fine.
Some snails still won't eat it off the block even with the above method and because it is likely that natively the snails eat foods high in calcium we need to make sure they get enough. This requires us adding the calcium to other foods. There is a study about the growing rates of Archachatina marginata and calcium sources. 20% Calcium carbonate was deemed the best amount, but it is undetermined whether this resulted in the healthiest shells or the fastest growth. 20% seems awfully high when you consider that fruits high in calcium such as papaya contain only 0.04% calcium. However, snails are known to live in calcium-rich soils and areas with a lot of limestone or natural chalk. This indicates they do get calcium from other sources:
"The availability of calcium in their diet determines if the shell is thick or thin. Many years ago in the 1930s juvenile shells of Arianta arbustorum, a common European land snail were raised under two diet conditions - calcium rich and calcium deficient. It was observed that both lots grew to the same size but those grown on the calcium rich diet had shells almost four times heavier than those grown on a calcium deficient diet. I have observed this diet restriction in Achatina fulica living on volcanic (calcium deficient) and coral (calcium rich) islands of the Pacific." http://www.calacademy.org/research/MAD/MAD_GUIDE_2.htm
Note: Having recently encountered a problem where a snail suddenly stopped eating cuttlefish and damaged its own shell quite badly, a diet of a mix consisting of various cereals and 50% powdered cuttlefish soon sorted the problem.
For alternatives to cuttlefish bone, solid, liquid and powdered click here.