Systematic Veterinary Virology

DIFFERENTIAL DIAGNOSIS

• Clinical signs associated with AHSV are clearly not pathognomic. Hence, the infection has to be differentiated from
• Viral
• Equine infectious anemia (Retroviridae) 
• Equine viral arteritis (Arteriviridae)
• Equine encephalosis (Reoviridae) (often occurs concurrently with AHSV; differentiable by absence of edema and lower mortality rates)
• Bacterial
• Anthrax (Bacillus anthracis)
• Protozoan
• Trypanosomiasis (Trypanosoma evansi)
• Piroplasmosis (Babesia caballi and Babesia equi) 
• Other
• Purpura haemorrhagica (lesions on necropsy tend to be more widely distributed in this condition than in AHS)