NUPTIAL PAD AMPUTATION IN AN AMERICAN BULLFROG (LITHOBATES CATESBEIANUS) WITH SQUAMOUS CELL CARCINOMA.

A 7-yr-old male captive American bullfrog (Lithobates catesbeianus) presented with a 2-wk history of an enlarged, ulcerated nuptial pad on the mediopalmar surface of the first digit of the left carpus. A 3-mm wedge biopsy of the mass was not diagnostic and differentials included an epidermal inclusion cyst or squamous cell carcinoma. No fungal or acid-fast organisms were cultured or noted on impression smear. Wide surgical resection of the mass and associated first digit were performed. Histopathology confirmed squamous cell carcinoma associated with the dermal nuptial gland with neoplastic cells extending close to deep surgical margins. Two months after surgery, no recurrence was noted. Although experimental tumor studies in amphibians are well documented, clinical reports of cutaneous neoplasia management in captive amphibians are scarce. Squamous cell carcinoma should be considered as a differential diagnosis when male anurans present with nuptial gland enlargement.

Spikes with short inter-spike intervals in frog retinal ganglion cells are more correlated with their adjacent neurons' activities.

Correlated firings among neurons have been extensively investigated; however, previous studies on retinal ganglion cell (RGC) population activities were mainly based on analyzing the correlated activities between the entire spike trains. In the present study, the correlation properties were explored based on burst-like activities and solitary spikes separately. The results indicate that: (1) burst-like activities were more correlated with other neurons' activities; (2) burst-like spikes correlated with their neighboring neurons represented a smaller receptive field than that of correlated solitary spikes. These results suggest that correlated burst-like spikes should be more efficient in signal transmission, and could encode more detailed spatial information.

Internal fixation of a femur fracture in an American bullfrog.

CASE DESCRIPTION: An adult male American bullfrog (Rana catesbeiana) was evaluated by the North Carolina State University College of Veterinary Medicine's Turtle Rescue Team following vehicular trauma. CLINICAL FINDINGS: A fracture of the left femur was suspected on examination and palpation of the hind limbs, but no other injuries or abnormalities were detected. While the bullfrog was sedated, whole-body radiographic views were obtained, which revealed a closed midshaft comminuted fracture of the left femur. TREATMENT AND OUTCOME: The fracture was repaired by use of an internal fixation technique that included Kirschner wires, a positive-profile pin secured along the femur with encircling sutures, and polymethylmethacrylate molded around the entire apparatus. There were no major complications during the postoperative rehabilitation period. One year after surgery, radiography revealed complete fracture healing and the bullfrog was released back into the wild. CLINICAL RELEVANCE: Presently, there are no widely accepted methods for fracture fixation in amphibians. Factors associated with their aquatic environment and lengthy fracture healing time must be addressed when planning fracture fixation strategies. In the bullfrog of this report, the applied internal fixation method provided effective long-term stabilization of the femur, allowed for normal movement, and enabled the bullfrog to be housed in an aquatic environment immediately after surgery.

An improved cannulation technique for prolonged blood sampling of the American bullfrog.

A T-cannula was used to collect serial blood samples from the sciatic artery of the American bullfrog (Rana catesbeiana). The horizontal arm of the cannula was implanted in the artery and the vertical arm employed to collect blood samples. The T-cannula allowed blood flow to continue in the cannulated artery and provided long-term, repetitive blood samples from conscious, caged, but otherwise unrestrained and undisturbed animals. The cannula functioned for at least 14 days, the maximum period investigated. Athough developed for studies on amphibians and reptiles, the technique appeared to be applicable, with appropriate modifications, to a variety of small animals.