Notoedric mange in western gray squirrels from Washington

From February 1998 to July 1999, 65 western gray squirrels (Sciurus griseus griseus) were trapped at three sites in Klickitat County, Washington (USA) as part of a home range and habitat use study. No squirrels (0/9) with man ge lesions were identified in the initial trapping session (February and Ma rch 1998) During all subsequent trapping sessions (August 1998 through July 1999), squirrels with lessions consistent with notoedric mange, caused by the mite Notoedres centrifera (douglasi), were captured or recaptured at al l three study sites. The diagnosis was confirmed by histopathology and exam ination of mites obtained from skin scrapings from two affected squirrels. Of the 56 squirrels captured from August 19 July 1999, 33 (59%) had charact eristic mange lesions, and 14 (42%) affected squirrels died directly of man ge or of secondary complications of mange. Only four breeding females of 22 radio-collared animals (males and females in the study population were kno wn to have survived the mange outbreak (12 died, 6 missing). Factors potent ially contributing to this mange outbreak include a mast crop failure in th e fall of 1998 and transmission of mites from animal to animal during trapp ing and processing sessions.