The Semantic Web Rule Language \cite{swrl} % http://www.w3.org/Submission/SWRL/
is a proposal for a rule language to be an extension of OWL-DL. Despite that the rule
language is datalog, the combination is not always finitely computable. 

In particular, if a class $C$ is defined as
\begin{verbatim}
:C owl:equivalentClass [ a owl:Restriction;
                         owl:onProperty :f
                         owl:someValuesFrom :C2 ]
\end{verbatim}
Then the rule $C2(?X) -> C(?X)$ (encoding that $C2$ is a subset of $C$) will not terminate. Thus, this combination is dangerous. Nonetheless, there are a couple of implementations of SWRL. 

