From Dog

Hypopyon, defined as the presence of pus or leucocytes in the anterior chamber, is usually caused by anterior uveitis with Pasteurella multocida infections[1].

This distinguishes it clinically from hyphema where there is blood in the anterior chamber.


  1. Purcell JJ & Krachmer JH (1977) Corneal ulcer caused by Pasteurella multocida. Am J Ophthalmol 83(4):540-542