Dear All, Attached is the *Question Sheet* for Diagnostic Exercise #*278, *contributed by Cassandra M. Powers. California Animal Health and Food Safety Laboratory, Davis, CA, and Purdue University, West Lafayette, IN. Author for correspondence cmpowers@ucdavis.edu The Diagnostic Exercises are an initiative of the Latin Comparative Pathology Group (LCPG), the Latin American subdivision of The Davis-Thompson Foundation. Members and non-members from any country of residence may contribute to these exercises. Please consider contributing a case to this initiative. It does not have to be unusual, and all pathology subspecialties are welcome! Please consult instructions on how to format and submit your DE at https://davisthompsonfoundation.org/diagnostic-exercises-instructions/ Previous cases are available at https://davisthompsonfoundation.org/diagnostic-exercise/