Abstract
On 5th December 2017, an adult male sub-Antarctic fur seal (Arctocephalus tropicalis) was reported as depressed and uninterested in food. The animal ate the day before but not well. A few hours later, on initial examination, the animal was almost non-responsive. He was treated with antibiotics, cortisone and intravenous fluids. He became progressively more dyspnoeic and oxygen was administered via a face mask. Despite continued treatment his condition deteriorated and he was euthanased. Gross necropsy findings included severe pleuritis and pneumonia. Histopathological findings included severe acute diffuse fibrinosuppurative bronchopneumonia with pleuritis and numerous intralesional bacteria. Pasteurella multocida was isolated from the right lung, left lung, kidney, spleen, liver and thoracic fluid.
On 8th December 2017, a sub-adult male New Zealand fur seal (Arctocephalus forsteri) was reported as being depressed, uninterested in food and vomiting. This animal was given antibiotics. Over the next few hours his condition deteriorated and he died. Gross necropsy findings included a severe septic peritonitis. Histopathological findings included congestion of most abdominal organs with focal aggregation of extracellular bacteria. P. multocida was isolated from the liver, spleen, myocardium, mesenteric lymph node and peritoneal fluid. The antibiotic sensitivities of both isolates were the same.
Both animals had been housed in the same enclosure with the New Zealand fur seal having been moved out of this enclosure five days prior to his death. Multiple swabs from around the enclosure were all negative for pasteurella.
An autogenous vaccine has been prepared but has not been used as no new cases have been detected.
P. multocida has previously been reported as causing mortalities in captive pinnipeds12 and found in association with other pathogens in free-range populations. Pasteurella is a normal inhabitant of the oral cavity in some pinnipeds3 and under certain circumstances in immune-compromised animals may cause disease2. No underlying disease processes were identified in the two pinnipeds described here and both appeared to be fit and healthy prior to this event.
Acknowledgments
The authors would like to thank the trainers and keepers of Sea World Australia for their assistance in caring for these animals.
* Presenting author
Literature Cited
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3. Hansen MJ, Bertelsen MF, Christensen H, Bisgaard M, Bojesen AM. 2012. Occurrence of Pasteurellaceae bacteria in the oral cavity of selected marine mammal species. Journal of Zoo and Wildlife Medicine. 43:828–835.