An adult, intact male alpaca was presented with an acute onset of unilatera
l scrotal swelling. Following complete physical and ultrasonographic examin
ation, the most likely differential diagnoses were orchitis, hematoma, and
testicular torsion. The animal was castrated and histopathologic evaluation
revealed unilateral orchitis. Streptococcus equi subsp. zooepidemicus was
cultured.