Another cause of paralysis in the rear legs is too big prey items..these can push against the spine and pinch the nerve, causing the rear legs to no longer function properly. If conditions are right, the food will eventually break down (depending on what it is, too large crickets, roaches, or grasshoppers, don't break down easily, superworms fed to very young dragons, or excessive amounts of mealworms and these can lead to actual blockages) if continual feeding to large items is stopped.
However, any sign of rear leg paralysis should be taken to a vet. Intestinal blockages can lead to death. Too large prey items fed constantly can also cause permanent blocks (ie won't pass through naturally) due to hard exoskeletons of the prey items sticking together and staying stuck, blocking the intestinal tract. MBD can also cause rear leg paralysis (or front legs, or both in worse cases) and this also needs to be look into. Blows or injuries to the spine can cause paralysis..though this won't be considered indigestible paralysis.
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PHLdyPayne