Abstract
Antigenic group 2 coronavirus was detected in a fecal sample of an adult alpaca by reverse transcription-PCR. The presence of alpaca coronavirus (ApCoV) in the small intestine was demonstrated by immune histochemistry with an antinucleocapsid monoclonal antibody that reacts with group 2 coronaviruses. Other common causes of diarrhea in adult camelids were not detected. We conclude that nutritional stress may have predisposed the alpaca to severe ApCoV infection.