Decision makers want more information on the presence, distribution, movement, and impacts of pathogens in wild animals to anticipate or assess the risk of pathogen spillover from wildlife to people or domestic animals or to better understand the conservation implications of contagious diseases in wildlife. There are many impediments to designing and implementing a wildlife health surveillance system that fulfils all the expectations for ‘good’ surveillance. There are well-known pragmatic limitations such as the inability to sample targeted populations consistently and regularly in a representative manner, lack of validated tests, and funding limitations that restrict surveillance to periodic surveys. The nature and impact of the biases on data collection, generation, management, quality, analysis, interpretations, and information sharing are poorly studied. We invite authors to address the question in the title.