Malnutrition is caused by lack of feeding, worms & parasites, and even incorrect temp. Check out my Basic Leopard gecko care for information on temp, housing, and feeding. If your having troubles with malnutrition, and your geckos temp and feeding habits are proper make sure to go to a reptile savvy vet and get your gecko tested for worms and parasites. Keep in mind that baby leopard geckos have smaller tail then adults, but your geckos tail should be nice and plump, and there stools should be neither hard or watery, whit a urite aka crystalized urine ake white spot on poo that is soft.
Skinny geckos tail example (I just got George in this picture and the previous owner sold him because they did not have enough time to properly take care of him, hence him being skinny)
Healthy baby geckos tail
Healthy geckos tail example. The tail can be bigger but he was eating crickets only at the time of the picture which are low fat. That's why its not is big as it could have been.
Healthy juvenile geckos tail
