  We determine the occurrence and explicitly describe the theta lifts on all
levels of all the irreducible generic representations for the dual pair of
groups $(\mathrm{Sp}_{2n}, \mathrm{O}(V))$ defined over a local nonarchimedean
field $\mathbb{F}$ of characteristic $0$. As a direct application of our
results, we are able to produce a series of non-generic unitarizable
representations of these groups.
