The free-ranging ring-tailed lemur (Lemur catta) program on St. Catherines Island has provided researchers an excellent opportunity to conduct behavioral research for over two decades. Transmission of infectious disease from native wildlife to this lemur population has been previously documented with raccoons (Procyon lotor), white-tailed deer (Odocoileus virginianus), gray squirrels (Sciurus carolinensis) and feral pigs (Sus scrofa) posing the biggest threats.1-3
An acute fibrinonecrotic enterocolitis has been documented in 14 ring-tailed lemurs over the last decade, with 10 of the cases occurring over the last 2 years. Younger lemurs were more commonly affected with ages ranging from 4 to 15 months. One 10-year-old male undergoing an introduction to a new troop develop signs and died from the disease. The onset of clinical signs was acute and included hypothermia, anorexia, lethargy, abdominal pain, and vomiting. Physical examination usually revealed a mid-abdominal mass. Gas-distended bowel loops were the most common radiographic finding. Clinical pathology abnormalities included leukocytosis, monocytosis, elevated packed cell volume, hypoproteinemia, hypoalbuminemia, hyperkalemia, and hyponatremia. Feces and tissue submitted for Salmonella, Shigella, Campylobacter, and Yersinia culture were negative in all cases. Toxin assays for Clostridium difficile and Clostridium perfringens were negative. Lawsonia intracellularis is the suspected etiology of this condition based on positive polymerase chain reaction and immunohistochemistry staining of feces and tissue from several lemurs, feral pigs and raccoons. Successful treatment depends on early intervention with fluid therapy, azithromycin, metronidazole, and analgesics. Oral vaccination with a product developed for domestic swine has had promising results.
1. Pung, O.J., J.S. Spratt, C.G. Clark, T.M. Norton, et al. 1998. Trypanosoma cruzi infection of free-ranging nonhuman primates on St. Catherine’s Island, Georgia, USA. J. Zoo Wildl. Med. 29(1):25–30.
2. Yabsley, M.J., T.M. Norton, M.R. Powell, et al. 2004. Molecular and serological evidence of tick-borne Ehrlichiae in three species of lemurs from St. Catherines Island, Georgia USA. J. Zoo Wildl. Med. 35(4): 503–509.
3. Yabsley, M.J., C.N. Jordan, S.M. Mitchell, T.M. Norton, and D.S. Lindsay. 2007. Seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, GA, USA. Vet. Parasitol. 144:28–32.