My pet Lola was born of an abandoned spitz-cross stray in Feb 2012. She had a thick white coat with brown ears and face mask, and a big brown spot on her rump where her tail is joined. Big deep chest and body but thin short legs (like that of the Pomeranian). Her tail is short and lifted up in sickle formation like a JRT cross. She had a few tiny brown spots on her legs.

Since last couple of years (after she turned 4+) she has begun to develop small brown patches all over her white body? Do dogs change their coats as they grow ? Is there more to this ? Could she be a chimera? Her unmaternal mother tried to bury her in our compost pit soon after she was born. Her body was shaped like a piglet and is still is big for her height. 

Should I get her DNA tested? Could being a chimera and not knowing it cause problems when treating for any infections ?