\usepackage {pstricks}
\begin{pspicture}(0,0)(5,5)\showgrid
\rput(1,1){\rnode{A}{Dog}}
\rput(2,4){\rnode{B}{Cat}}
\rput(4,2){Mouse}
\ncline{A}{B}
\nccurve[linestyle=dotted]{A}{B}
\ncarc[linestyle=dashed]{A}{B}
\end{pspicture}