Serum protein analyses are beneficial tools used to evaluate the health status of animals in a clinical veterinary setting. Capillary zone electrophoresis (CZE) is becoming more commonly used in diagnostic laboratories, and commercial reagents for the quantitation of acute phase proteins (APP) are available for validation in nondomesticated mammals. With increased numbers of red foxes (Vulpes vulpes) presenting to wildlife facilities with sarcoptic mange, there is a potential for a clinically impactful tool in protein electrophoresis and/or APP quantitation in this species. In this study, we evaluated 29 samples from 17 free-ranging red foxes from Illinois by CZE and APP quantitation. Serum amyloid A (SAA) reagents were validated for use in this species. Of the 17 red foxes enrolled in this study, 7 of them were successfully treated for sarcoptic mange, rehabilitated, and released or transferred to a licensed wildlife rehabilitator for continued care. All red foxes that were successfully treated in this study exhibited decreased SAA levels before release or transfer from the facility, and six of the seven red foxes showed a decrease in γ-globulin levels on release or transfer compared with intake. The results of this study provide preliminary data on serum protein analyses of red foxes, and these assays may have applications as diagnostic tools for assessing the health of the species.