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Meeting of Poultry
Clinicians and Pathologists
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Clinicians and Pathologists
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Salinomycin Toxicosis in Turkeys: Serum Chemistry as an aid to early diagnosis J.L. Neufeld
Salinomycin is an ionophore coccidiostat, which is specifically toxic to muscle cells. The enzymes released from damaged muscle are creatine kinase (CK) and aspartate aminotransferase (AST). A flock of 7000 Nicholas breeder turkey hens at 41 weeks of age were in full production. Coincident with delivery of a new batch of feed and allowing time for it to reach the feeders, these hens began to show signs of hyperthermia (panting), segregation from companions, paralysis and sudden death. Losses eventually reached a total of 18.5% (1296).
Necropsy of dead birds revealed only slight edema of adductor muscles of the legs. Histologically, these affected muscle bundles contained fractured and ruptured myofibres, but the changes were minimal in most birds. Because of this indication of muscle damage, serum was collected and tested on a multi-channel analyzer (Coulter Dacos) for CK and AST values. A group of healthy, unstressed turkeys were also tested. Results Resting healthy turkeys –CK
Downer & stressed birds – CK
*Significantly elevated
Interpretation Values of serum AST were usually not elevated early in the clinical syndrome and were not considered useful as early indicators of muscle damage. Values of serum CK were markedly elevated in clinically ill birds and were useful as confirmation of early muscle damage.
Toxicology Testing of the suspect feed revealed levels of 15.5 ppm of Salinomycin sodium (Plant Products Division, Agric. Canada).
Discussion Griffiths et al (1) reports that turkeys react to 15 ppm of Salinomycin with elevated CK values reaching a range of 105,000 to 1,246,000 I.U. In the case present here, the values ranged from 5,416 to 113,950 I.U. They are not as high as those reported elsewhere, but were still confirmatory of specific muscle damage. One precaution to note is the fact that 3/8 birds had normal values. Therefore, sufficient birds should be tested to ensure that false negatives are avoided. A minimum of 10 would seem to be adequate. Losses stopped within 10 days, but production suffered to some degree for the remainder of the season.
References Griffiths, et al. Salinomycin Poisoning in Point-of-lay Turkeys. Australian Vet. J. 66:326-329. 1989.
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