All of our pets are buried when the pass on.
Pet fish get a burial at sea of course (the toilet)
We have also cremated one cat, and kept the ashes. He was just too special to our family to part with him....so he remains with us today.
But....other than that, all family pets are buried in the same secluded, rural area, sort of like our own private pet cemetary. With grave markers, a "coffin" of some sort, and a little prayer...