John P. Sundberg,¹ Karen Morris,² Wayne D. Lancaster<sup>3

1</sup>Department of Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana, Illinois 61801, USA
²Department of Inland Fisheries and Wildlife, Augusta, Maine 04333, USA
³Departments of Obstetrics and Gynecology and Pathology, Georgetown University Medical Center, Washington, D.C. 20007, USA