Studies on an ulcerative stomatitis-obstructive rhinitis-pneumonia disease complex in hatchling and juvenile sea turtles Chelonia mydas and Caretta caretta

Abstract

Three bacterial diseases (ulcerative stomatitis, obstructive rhinitis and pneumonia) and associated complexes were together responsible for mortality rates of up to 70% in farmed and oceanarium-reared turtles (Chelonia mydas and Caretta caretta). Hatchlings 5 to 12 wk old and juveniles 3 to 6 mo old were particularly susceptible to ulcerative stomatitis and bronchopneumonia respectively (58.6 and 58.3% of the cases diagnosed). Obstructive rhinitis was secondary to ulcerative stomatitis, being present in 70% of hatchlings with mouth rot or "canker." Focal pneumonia occurred more frequently in juveniles (81.8% or 9/11 affected). The 5 disease complexes observed (ulcerative stomatitis - bronchopneumonia; ulcerative stomatitis - obstructive rhinitis; ulcerative stomatitis - obstructive rhinitis - bronchopneumonia; obstructive rhinitis - bronchopneumonia; and ulcerative stomatitis - focal pneumonia) were equally distributed amongst hatchlings and juveniles. It was not possible to compare the relative susceptibility of green turtles and loggerheads, because of the small number of loggerheads involved (3). The percentage of farmed and oceanarium-reared turtles showing one or more of these diseases was similar (65% (65/100) and 66.6% (10/15) respectively). The clinico-pathological features of the major diseases are described. Three bacteria (Vibrio alginolyticus, Aeromonas hydrophila and Flavobacterium sp.) were repeatedly isolated from cases of ulcerative stomatitis and obstructive rhinitis. In addition to the above organisms 4 genera of fungi (Paecilomyces sp., Penicillium sp., Aspergillus sp. and Fusarium sp.) were recovered form caseous material lodged inside the trachea and bronchi of turtles with bronchopneumonia. A therapeutic regime was tested on 42 hatchlings, 7 to 8 wk old, using antibiotics and a topical disinfectant. The survival rate of individually-reared hatchlings (71.5%) was significantly higher than the control group (28.6%, p < 0.01) but significantly higher than their group-reared counterparts (57.2%, p < 0.05).