Drury R. Reavill1, DVM, DABVP (Avian practice), DACVP; Ben Okimoto2, DVM; Bradd C. Barr3, DVM, PhD; Robert Nordhausen3, MA; Robert E. Schmidt1, DVM, PhD, DACVP
Abstract
Infectious causes of pneumonia in tortoises include viruses, bacteria, fungi, and parasites. An uncommonly recognized cause of pneumonia in tortoises is an intranuclear protozoa reported in several species of captive tortoises in the United States.3 This has been described in two captive-bred juvenile radiated tortoises (Geochelone radiata), two adult radiated tortoises, one wild caught adult impressed tortoise (Manouria impressa), one captive-bred juvenile leopard tortoise (Geochelone pardalis), and three Travancore tortoises (Indotestudo forstenii).1-3 All tortoises had intranuclear coccidial parasites in a variety of epithelial tissues. Inflammation of the lung was noted in five tortoises and one had a proliferative pneumonia.1-3
Over a period of 4 mo, four young adult radiated tortoises became weak and lethargic with mouth breathing before they died. The animals were kept together in the same exhibit and had been moved to this enclosure 5 mo earlier. The first two tortoises of the outbreak had a proliferative pneumonia with inflammatory exudate and intranuclear inclusions within respiratory epithelial cells. These inclusions could be found in a variety of other epithelial cells (bile ducts, gastric mucosa, and thyroid follicular epithelium). By electron microscopy it was determined that the protozoa were within the nucleus and some appeared to be invaginating or pushing into the nucleus. Their morphology is compatible with an Apicomplexa protozoan. These protozoa reacted weakly with Sarcocystis neurona antisera and were negative by immunohistochemistry for Toxoplasma gondii, Neospora, and Sarcocystis falcatula.
Various therapies and supportive care were used with little effect. The last two tortoises also developed pneumonias; however, the previously described epithelial inclusions were not recognized. Both of these tortoises were given potentiated sulfonamides (Tribrissen® Schering-Plough Animal Health Corporation, Union, New Jersey, USA) as part of their therapies. Four other radiated tortoises and one Madagascar angulated tortoise (Geochelone yniphora) penned with these four, were relocated and have survived.
Literature Cited
1. Garner MM, C Gardinar, M Linn, TS McNamara, B Raphael, NL Lung, D Kleinpeter, TM Norton, E Jacobson. 1998. Seven new cases of intranuclear coccidiosis in tortoises: an emerging disease? In: Proc. Am. Assoc. Zoo Vet. Am. Assoc. Wildl. Vet. Joint Conf. Omaha, NE. p 71–73.
2. Jacobson ER, J Schumacher, SR Telford, EC Greiner, CD Buergelt, CH Gardinar. 1994. Intranuclear coccidiosis in radiated tortoises (Geochelone radiata). J. Zoo & Wildl. Med. 25(1):95–102.
3. Origgi FC, ER Jacobson. 2000 diseases of the respiratory tract of chelonians. Vet. Clin. North Am. Exot. Anim. Pract. 3(2):537–549.