Large chain pet stores, like Petco and Petsmart, are notorious for neglect and abuse of the animals they sell. People especially look over animals that are not cats or dogs. People think “Oh its just a fish” or see reptiles and birds as display items. These stores sell the animals as a commodity.
I personally have gone and talked to someone about their ball pythons because they had no water, humidity under 15 degrees and no shelter for the two little wrinkly pythons. And I have seen and heard stories about employees who do their best and inform costumers about the animals. Take time and research the animal you want and if you can afford it and care for it properly and find a someone/or group who sell healthy animals.