Abstract
A 44-year-old captive female dolphin presented with acute onset inappetance and lack of response to trainers. Initial blood work was unremarkable with the exception of a low iron level, and symptomatic treatment with oral bismuth salicylate was provided based on suspicion of gastrointestinal disorder. Recovery from initial presentation was uneventful and she was clinically normal before relapsing 6 days later with inappetance and low body temperature. Blood work this time showed severe leukopenia with degenerative left shift, elevated inflammatory markers, azotaemia, hyperkalaemia, hyperphosphataemia and elevated liver values. Antibiotics (cefovecin at 8 mg/kg IM and enrofloxacin 5 mg/kg IM), Filgrastim 1.5 µg/kg IM and oral fluid therapy were administered but her condition deteriorated rapidly and she died within 48 hours of relapse. Significant gross necropsy findings were peritonitis with fibrinopurulent exudate, hemorrhagic gastroenteritis, reactive hemorrhagic pancreatic lymph node and bilateral pulmonary edema. Histopathology revealed necrotizing to necrohemorrhagic inflammation with variable numbers of coccoid organisms extending from pancreas to adjacent peripancreatic adipose, pancreatic lymph node, visceral peritoneum and stomach. Streptococcus agalactiae was isolated from the lesions above, peritoneal fluid and various major organs including the brain. Streptococcus agalactiae or group B Streptococcus infections have been reported in numerous animal species including marine mammals.1,2 The isolate from this case was further strain typed and shown to be novel for dolphin species.3 Origin of infection in this case was undetermined.
Acknowledgements
We thank our colleagues and trainers at the Veterinary Department and Marine Mammal Department of Ocean Park for their dedication and care for this special animal. The authors also thank Professor Patrick Woo and colleagues at the Microbiology Department of The University of Hong Kong for their interest and support in this case.
* Presenting author
Literature Cited
1. Evans JJ, Pasnik DJ, Klesius PH, Al-Ablani S. 2006. First report of Streptococcus agalactiae and Lactococcus garvieae from a wild bottlenose dolphin (Tursiops truncatus). J Wildl Dis. 42:561–569.
2. Zappulli V, Mazzariol S, Cavicchioli L, Petterino C, Bargelloni L, Castagnaro M. 2005. Fatal necrotizing fasciitis and myositis in a captive common bottlenose dolphin (Tursiops truncatus) associated with Streptococcus agalactiae. J Vet Diagn Invest. 17:617–622.
3. Delannoy CMJ, Crumlish M, Fontaine MC, Pollock J, Foster G, Dagleish MP, Turnbull JF, Zadoks RN. 2013. Human Streptococcus agalactiae strains in aquatic mammals and fish. BMC Microbiology. 13:41–49.