Severed body parts of a small brown dog have been found in a park in Sydney's inner west, prompting police to appeal for the public's help in the shocking case of animal cruelty.

Police were called to Whites Creek Valley Park, Annandale, on Saturday morning after a local resident found the torso of a dog.

Officers found more remains of the dog, possibly a terrier, including its head, legs and tail scattered near a skateboard ramp.

Inspector Sean Daley, of Leichhardt Local Area Command, said police were immediately able to tell the dog hadn't been attacked by another animal.

"It was quite obvious. The legs appeared to be cut off, along with the head and the tail."