This data set is composed of all events in the Wildlife Health Information Sharing Partnership Event Reporting System (WHISPers) between 1/1/2000 and 12/31/2020 from counties bordering the Chesapeake Bay. Relevant fields include WHSPers ID number, estimated number of animals affected, event start and end dates, states, counties, species involved, event diagnoses, etiological category of the primary cause/diagnosis, and whether concurrent algal blooms or toxins were reported at the time of the event. Additional information from NWHC case 24171is provided including: WHISPers event ID, case number, accession numbers, state, county, collection date, species, presence or absence of liver necrosis, and cause of death.