Mental ill-health associated with animal care work, coupled with a current shortage of animal care workers (ACWs), highlights the need to support this population's wellbeing. Guided by the Job Demands-Resources model of burnout and the principles of positive occupational health psychology, we aimed to explore mental ill-health in ACWs and identify potential risks and protective factors for their wellbeing. ACWs (n = 217) completed an anonymous online questionnaire with measures of post-traumatic stress disorder (PTSD) symptoms, psychological distress, burnout, grief, social support, organizational support, and empathy for animals. We also asked an open question about what participants liked about their work. Our sample had a higher incidence of mental ill-health than the Australian general population. Multiple regression analyses suggested grief may be a job demand for ACWs, significantly accounting for 2.8-4.3% of the variance in burnout. Likewise, organizational support may be a job resource for ACWs, significantly accounting for 17.3-25.5% of the variance in burnout. Finally, qualitative content analysis indicated that ACWs enjoyed professional accomplishments, interpersonal interactions, and contact with animals as part of their work. We discuss our results and how they may be used to inform the implementation of workplace changes that support ACWs' wellbeing.