A mouse model of anosmia can be achieved by application of zinc sulfate on the nasal mucosa of the animals. Here you can find a reference:
Does intranasal application of zinc sulfate produce anosmia in the mouse? An olfactometric and anatomical study, McBride, Slotnick and Margolis, 2003 (https://www.ncbi.nlm.nih.gov/pubmed/14627534)