Sometimes puppies when weaned/taken away from their mother and littermates to early on in life can show this behaviour.
Ideally they should stay with mom and other pups until at least 8 weeks of age, but a lot of times it ends up being 6 weeks.

Answered by VetTech on February 27, 2010 at 2:39pm - report abuse

I agree with VetTech...your puppy was likely weaned too early or suddenly, and is still seeking that comforting sensation of suckling.
"Wool-sucking" or "flank sucking" is also a common obsessive-compulsive disorder in some dogs, particularly Dobermans. If you think this could be the case, talk with a veterinarian who has an interest in canine behavior, or contact a certified pet behaviorist (this is NOT the same as a dog trainer)....you should be able to find one through a veterinary teaching hospital/university, or perhaps by doing an online search.

Answered by cheytara on March 1, 2010 at 9:55pm - report abuse