Case Report: Immune-Mediated Polyarthritis in a Bearded Dragon (Pogona vitticeps)

Abstract

A 1-year-old captive female bearded dragon (Pogona Vitticeps) was presented with swelling of all four limbs and arthrosclerosis that had been present for one week. On physical examination, all the limbs presented with pain on palpation, especially the left forelimb. Under X-ray examination, expanded articular spaces without erosive lesions or periosteal reaction were noted in the elbow and stifle joint, together with swelling of the surrounding soft tissue. Lesions were most severe in the left elbow joint. Arthrocentesis was performed for analysis of synovial fluid and cytology. Under microscopic examination, ＞10 cells/high power field (HPF) were found, in which inflammatory cells predominated. The cells comprised 10.7% synovial cells, 43.7% monocytes, 30.0% lymphocytes and 15.6% heterophils; the monocytes showed a prominent toxic reaction, and phagocytosis was also recorded. No microorganisms or crystals were observed. All synovial fluid cultures were negative. Based on the results of hematology and cytology, immune-mediated polyarthritis was diagnosed. The total white blood cells count (TNCC) and the percentage of polymorphonuclear neutrophil leukocytes (%PMN) were obtained in an attempt to obtain a diagnosis, and the results suggest a diagnostic value for this evaluation method in reptiles. The patient was treated with prednisolone at 1.5 mg/kg orally once per day (s.i.d.) with a tapering program, which resulted in a good response.