Perinatal death ranks among the top three categories of mortality in the Florida manatee (Trichechus manatus latirostris), and has averaged 23% of overall mortality over the last 10 yr. Similarly, young juveniles comprise a significant proportion of cases presented to manatee rehabilitation facilities. Causes of perinatal mortality vary considerably, and may include still birth, abandonment and/or separation from the mother, cold stress, brevetoxicosis, predation, and omphalitis. Most causes of manatee perinatal mortality, however, remain undetermined due to decomposition of recovered carcasses. This case report describes a 1.59 m male Florida manatee that was rescued due to weakness, severe body lesions, and lethargy. On physical examination, the animal demonstrated multifocal skin abscessation and necrosis with excavation of tissue in the fluke, peduncle, and flippers. The manatee was euthanatized due to the severity of its condition and poor prognosis. Necropsy revealed extensive septicemia, with purulent material in the umbilicus, urachus, urinary bladder, kidney, pleura, flipper joints, vertebral column, and spinal cord. Numerous anaerobic bacterial species, including Fusobacterium spp., were cultured from the abscesses. Histopathology confirmed the clinical diagnosis of bacterial septicemia, with particularly devastating necrotic damage to the infected spinal cord. The root of infection in this manatee calf was believed to be located in the umbilicus. Complete evaluation of freshly dead juvenile manatees such as this case is important to better understand the causative factors and pathogenesis of disease in this significant manatee mortality category.
The authors thank the SeaWorld Animal Care and Rescue, Florida Fish and Wildlife Conservation Commission, and University of Florida staffs for their assistance with this case.