Differentiation of salmon poisoning disease and Elokomin fluke fever: studies with the black bear (Ursus americanus)
Farrell, R.K.; Leader, R.W.; Johnston, S.D.
American Journal of Veterinary Research 34(7): 919-922
1973
ISSN/ISBN: 0002-9645 PMID: 4720678 Document Number: 69279
Of five black bears fed trout infected with Nanophyetus salmincola metacercariae, four developed anorexia, lassitude and diarrhoea on days 9-12, and P.M. displayed enlarged mesenteric lymph nodes. Three yielded rickettsial bodies from lymph node smears. All five dogs fed infected trout developed symptoms of salmon poisoning disease (SPD) by the seventh day, and four died shortly after. One survived, and was immune to subsequent feeding of infected fish. All but five of 23 dogs inoculated i/p with infected bear lymph node developed symptoms which were similar to those of SPD, but differed in that the incubation lasted 5-12 days, the fever was less intense but more prolonged than in SPD, the dogs recovered, and lymph nodes remained enlarged 2-3 weeks after recovery. Three months later, the dogs were given a challenge meal of infected fish, and developed typical SPD symptoms; the majority died. The SPD-like syndrome was passed by blood inoculation from dogs infected through bear lymph node to susceptible dogs; the latter died after challenge feeding of infected fish. The SPD-syndrome has been named Elokomin fluke fever (EFF), and its agent is thought to exist with the SPD agent in infected fish. In dog, the SPD agent asserts itself, while black bears selectively react to and transmit the EFF agent. No cross immunity develops between the two agents.