Dyskinetic Syndrome
Based on my own experience, this is my opinion of reasons why a tarantula might have Dyskinetic Syndrome(DKS). - DKS is a syndrome, meaning that there is no known cure or known reason why it happens, only speculative opinions . It has yet to be proven by science that it is a genetic problem or that it is contagious. My theory is that it may be caused by exposure to an insecticide. Typically insecticides are used in the manufacturing of peat moss ,potting soil ,walnut shell and many other materials commonly used for planting and gardening. For example, potting soil was being used as a substrate for a person keeping a reptile with no harmful effects even though there was insecticides in the soil. However ,his tarantulas were twitching and suffering for weeks until death occurred. The insecticides put into materials not designed for tarantulas are systemic and will cause nerve damage and dehydration to spiders. Once injested or exposed ,they will never leave the body. These chemicals or insecticides are not airborn , but more likely present in the substrate material. Every person that I have ever talked to about DKS has used a substrate material made for something else besides tarantulas. Another example is walnut shell bedding used for reptiles. This stuff is deadly. Walnut trees are sprayed routinely with systemic insecticides to prevent worms and beetles from eating the nut. After the walnuts are processed and shelled, the meat of the nut is sold as food for human consumption and the shells are sold as pet substrate and for other things. The insect killing poisons will remain to a degree on the shell. And can not be removed. Even though a spider is not an insect ,it can still die from many types of insecticides and therefore it is critical to never use any kind of substrate that is not 100% free from any type of insecticides. I use vermiculite only
or cocoa fiber.