Mycotic disease in the common New Zealand gecko (Hoplodactylus maculatus)

Two adult female geckoes (Hoplodactylus maculatus) from the National Wildlife Centre, Mt Bruce, Masterton, died within the period of a month and were presented to the Department of Veterinary Pathology and Public Health at Massey University for necropsy. The first gecko had numerous 1-2 mm diameter punctate ulcers of the skin over the ventral and dorsal regions of the body. The second animal had slight discolouration of some of the scales. Skin swabs were taken from each case for culture. There were no other gross lesions apparent at necropsy. Histologically, the only lesions in the first gecko were areas of epidermal and dermal ulceration involving fungi and bacteria. In the second gecko, there was limited inflammation in the skin, but in the lungs there was necrosis of the pulmonary septae and constituent muscle bundles caused by fungi whose septate mycelia extended into adjacent large blood vessels and caused mycotic thrombi; hyphae were also found in the spleen and liver. Paecilomyces sp. septate fungus was recovered from both geckoes and Pseudomonas spp. and a mixed Gram-negative flora were recovered from the cutaneous lesions on culture. The death of the first gecko was considered to be due to widespread ulcerative dermatitis, while that of the second gecko was thought to be due to mycotic pneumonitis and mycotic septicaemia. It is believed that environmental factors, such as cold temperature and high humidity, contributed to a reduction in the immune response in the affected geckoes, with the consequent development of overwhelming fungal infections.