This scenario involves two concepts from the IPC:
\begin{enumerate}
\item **Force (S. 349):** A person is said to use force if they cause motion to another, including by "inducing any animal to move." By inciting the dog, 'A' uses force against 'Z'.
\item **Criminal Force (S. 350):** A person uses criminal force if they intentionally use force without consent, intending to cause injury, fear, or annoyance.
\end{enumerate}
Since 'A' used force (via the dog) with the specific intent to cause injury, fear, or annoyance, the act amounts to the use of criminal force. Assault (S. 351) is merely the apprehension of force, whereas here the force is actually applied.