What's Your Diagnosis? Eastern Painted Turtle, Chrysemys picta
J Herpe Med Surg 12[1]:33-35 Spring'02 Case Report 7 Refs

History A 181 g, adult, free-living, female eastern painted turtle, Chrysemys picta, was presented after being hit by a car. Upon physical examination, the turtle was bright and alert. An open fracture of the third, fourth, and fifth vertebral scutes and the underlying bone was identified. The fracture of the caudal vertebral scutes and underlying bone was visible on the dorsoventral radiographic view. The lateral view revealed a displaced vertebral fracture between the fifth and sixth trunk vertebrae. The turtle was euthanized due to the poor prognosis for release into the wild. A post mortem examination confirmed the radiographic diagnosis of a displaced vertebral fracture between the fifth and sixth trunk vertebrae, and consequent transection of the spinal cord. Discussion This case emphasizes the importance of differentiating between the response to a painful stimulus and the withdrawal reflex, as well as the value of plain radiography in the assessment of spinal cord injuries. An intact deep pain response indicates that a stimulus is carried via the spinal cord to the cerebrum, whereas a withdrawal reflex only indicates that the spinal reflex arc is intact. This arc consists only of the peripheral nerves and the spinal cord segment from which they originate. Therefore, the withdrawal reflex is merely a spinal reflex and does not require any input from the cerebrum. If the spinal cord is completely transected cranial to the segments that are responsible for the reflex, the reflex is present despite the lack of conscious perception of the painful stimulus. In the authors' experience, it can be very challenging to differentiate deep pain from an intact withdrawal reflex in most chelonians, due to the inconsistency of response to a painful stimulus. This response can be affected by many different factors including the level of stoicism, body temperature during the examination, excitement of the patient, and shock. It has been shown that neurological examination techniques developed for use in dogs and cats are also applicable for turtles due to the similarities in the basic organization of the nervous system in mammals and turtles. Therefore, most of the same techniques used in a neurologic examination for a dog and cat can be applied to a turtle. However, there are anatomic differences in the nervous system of reptiles compared with mammals that make reptiles more capable of spinal cord regeneration. It has been noted that chelonians apparently have the ability to recover from some serious spinal injuries, but it is important to consider the cost and stress associated with extended captivity when making decisions regarding treatment in animals intended for release.