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Diagnostic histological findings in Yosemite toads (Bufo canorus) from die-off in the 1970s

January 1, 2001

Twelve adult and 25 larval Yosemite toad (Bufo canorus) specimens from the eastern Sierra Nevada of California were examined histologically for evidence of infectious, toxicological, and degenerative diseases. The preserved toads were selected from 21 that had been salvaged or collected during a die-off in 1976-1979 that immediately preceded a population decline. Causes of death of four toads were determined histologically; clinical signs and field observations suggested causes of death of three more. Four toads died of infectious diseases, including chytridiomycosis of the skin (N = 1), bacillary septicemia (N = 2), and combined chytridiomycosis and bacterial septicemia (N = 1). Infections by a funguslike organism (Dermosporidium penneri), renal myxozoa (Leptotheca ohlmacheri), larval Rhabdias, various gastrointestinal nematodes, urinary bladder flukes, and lung flukes were detected in five specimens. No evidence of degenerative diseases, virus infections, or intoxications was found. The variety of lethal diseases and our inability to determine the causes of death of five specimens suggests that one or more histologically undetectable diseases or intoxications may have also contributed to the deaths and population decline.

Publication Year 2001
Title Diagnostic histological findings in Yosemite toads (Bufo canorus) from die-off in the 1970s
DOI 10.2307/1566028
Authors D. Earl Green, Cynthia Kagarise Sherman
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Herpetology
Index ID 1003757
Record Source USGS Publications Warehouse
USGS Organization National Wildlife Health Center