Other diagnostic tests included West Nile virus (WNV) and eastern equine encephalitis (EEE), IgM capture ELISA (2), equine herpes virus‐1 (EHV‐1) PCR (2), muscle biopsy (2), urinalysis (2), Schirmer tear test (2), culture and sensitivity of an abscess (1), otoscopy (1), and cytology of otic discharge (1). Here, CD40LG is linked to eastern equine encephalitis.