While it is well-established that infection can lead to changes in physiology, less is known about how visual exposure to diseased conspecifics can influence an organism’s physiological state. Such social cues of infection can result in avoidance behavior, but less is known about how these cues affect the immune system. Exposure to a perceived immune threat could stimulate innate immune responses, which would increase the response time to an immune threat and potentially reduce susceptibility to infection. To test this, we examined how social cues of infection affect complement activity, white blood cell differentials, and cytokine gene expression in canaries (Serinus canaria domestica) that are housed in visual contact with either control conspecifics or conspecifics infected with the bacterium Mycoplasma gallisepticum. Our preliminary data suggests that immune activation occurs in birds exposed to a social cue of infection around 6-12 days post-inoculation, which is also when infected stimulus birds exhibited the greatest degree of lethargy and disease severity. Future research should explore whether immune activation following a social cue of infection confers any protection against infection, such as increased recovery time or reduced disease severity.