Pansteatitis of unknown etiology associated with large-scale Nile crocodile (Crocodylus niloticus) mortality in Kruger National Park, South Africa: pathologic findings.
Annual mortality events in Nile crocodiles (Crocodylus niloticus) in the Olifants River Gorge in Kruger National Park, South Africa, were experienced between 2008 and 2012, during which at least 216 crocodiles died. Live crocodiles were lethargic. Necropsy examination of 56 affected crocodiles showed dark yellow-brown firm nodules in both somatic fat and the abdominal fat body. In all of the 11 crocodiles submitted for histology, degenerative, necrotic, and inflammatory changes supported a diagnosis of steatitis in both fat types. Crocodiles are apex predators in this anthropogenically changed aquatic ecosystem that is used by humans upstream and downstream from the park for domestic, agricultural, fishing, and recreational purposes. This pathologic review of pansteatitis in crocodiles in the Olifants River system was part of a broad multidisciplinary research program. To date, no definitive causative agent has been identified. Epidemiologic evidence suggests that this event may have been a one-time event with long-standing repercussions on the health of the crocodiles. Pathologic findings are rarely documented in wild crocodilians. This study also reports on other conditions, including the presence of coccidian oocysts, capillarid and filaroid nematodes, digenetic trematodes, and pentastomes.
Research and Scientific Services Department, National Zoological Gardens of South Africa, P.O. Box 754, Pretoria 0001, South Africa. emily@nzg.ac.za
Emily P
EP
Lane
Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X 04, Onderstepoort 0110, South Africa.
Fritz W
FW
Huchzermeyer
Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X 04, Onderstepoort 0110, South Africa.
Danny
D
Govender
State Veterinary Services, P.O. Box 12, Skukuza 1350, South Africa.
Roy G
RG
Bengis
SANParks, Scientific Services, Private Bag X402, Skukuza 1350, South Africa.
Peter E
PE
Buss
SANParks, Scientific Services, Private Bag X402, Skukuza 1350, South Africa.
Markus
M
Hofmeyr
Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X 04, Onderstepoort 0110, South Africa.
Jan G
JG
Myburgh
Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X 04, Onderstepoort 0110, South Africa.
Johan C A
JC
Steyl
SANParks, Scientific Services, Private Bag X402, Skukuza 1350, South Africa.
Daniel J
DJ
Pienaar
Research and Scientific Services Department, National Zoological Gardens of South Africa, P.O. Box 754, Pretoria 0001, South Africa.
Antoinette
A
Kotze
D000273:Adipose Tissue / Q000473:pathology; D000489:Alligators and Crocodiles; D000818:Animals; D017753:Ecosystem; D005260:Female; D008297:Male; D013019:South Africa / Q000453:epidemiology; D013231:Steatitis / Q000453:epidemiology / Q000209:etiology / Q000401:mortality*; D013696:Temperature