Ours are all buried. Only my beloved Twitchie, who was PTS in winter when the ground was frozen, was cremated and her ashes, in their urn, are buried too.
Funny, I was thinking of this last night. After 57 years in her house my Mum has sold it and moved to an assisted living facility. There's a regular little pet cemetary in the back. But all signs of pets have likely assimilated with the soil by now. We have our precious memories of them in our hearts and souls and Teddy and Tommy, Tabby, Fluff and Puff, another Tommy, Tacky and Sam are safe there forever. I thought it might upset me when the house was sold but not really. Instead I am rather enjoying the memories thus prompted.