How to care for a dehydrated turtle?
This happens sometimes especially when he’s just come up from hibernation. See Post-Hibernation Turtle Care. Rinse the dirt off him under a faucet. Put him in a mixing bowl with high sides that he can’t climb out of, and fill it with warm water up to his plastron (the bottom part of his shell). He should be able to rest comfortably in the water without having to hold his head up to keep it out of the water. Let him soak and drink, and replace the water every 15 minutes with fresh warm water. This is because he may start urinating or defecating in the water. A severely dehydrated turtle may need to go through this soaking routine for a few hours, and it’s not unusual for one to double his weight after soaking.