**5. Conclusions**

Our studies of four host species indicated a low proportion of B lymphocytes, T lymphocytes and plasma cells and a high proportion of macrophages in response to *S. scabiei* infestation, suggesting that these species mount a primarily innate immune response and are relatively poor at developing an adaptive immune response to this pathogen. Our findings further sugges<sup>t</sup> that sarcoptic mange skin lesions may reflect a substantial humoral immune response in fox or a cellular immune response in chamois. Our observation of highest macrophage abundance in wolves may help explain their apparently more e ffective immune response against *S. scabiei.*

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2076-2615/10/7/1146/s1, Figure S1: Immunohistochemical technique in positive controls; lymph node from badger.

**Author Contributions:** Conceptualization, A.B.; methodology, I.Z.M., Á.O., I.S., C.P.-M., M.J.G.-I., J.F.G.M., and A.B.; validation, C.P.-M., M.J.G.-I., J.F.G.M., and A.B.; formal analysis, I.Z.M., Á.O., C.P.-M., M.J.G.-I., J.F.G.M., and A.B; investigation, I.Z.M. and A.B.; resources, A.B; data curation, C.P.-M., M.J.G.-I., J.F.G.M., and A.B.; writing—original draft preparation, I.Z.M. and A.B.; writing—review and editing, I.Z.M., Á.O., C.P.-M., M.J.G.-I., J.F.G.M., and A.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was partially supported by the Principado de Asturias, PCTI 2018–220 (GRUPIN: IDI2018-000237 and FEDER). Ms. Ileana Z. Martínez was supported by a Fundación Carolina PhD scholarship (2017 call).

**Acknowledgments:** The authors would like to thank the Vice-Ministry of the Environment of the Principado of Asturias. The authors thank A. Chapin Rodríguez for critically reviewing the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
