It is normal for a newborn pup to suckle and knead with its paws as it nurses. (See Reference 3, p. 25). Any time you see young mammals feeding, these behaviours occur. Some dogs continue this behaviour into adulthood. According to Gwen Bailey, author and dog behaviour specialist, "Object sucking can occur in any breed of dog; it has been known in working dogs like border collies, gun dogs like springer spaniels, terriers like Westies, hounds like daschunds and crossbreds." It can be difficult to determine what this behaviour means and what you should do in response to this behaviour.
Why Do Dogs Suckle as Adults?
Psychologist David M. Levy tested the supposition that dogs suckle because they have been weaned too early or are expressing an unfulfilled need from the time it was with its mother. Levy verified his supposition by depriving puppies of adequate suckling. Puppies raised in larger litters where suckling was curtailed due to competition with litter mates may demonstrate the same effect. Psychological Review reported the deprived puppies began suckling objects and continued to do so after weaning. This experiment determined suckling was not a result of aggression.
What Does Adult Suckling Mean?
Gwen Bailey, author and dog behaviour specialist, compares the suckling behaviour to human babies who suck their thumbs or carry a special blanket or toy with them. She believes this behaviour is a method of self-comforting. Bailey suggests more sensitive animals prefer to suckle to assuage their sensitivities. She also connects suckling to the dog's need to relieve feelings of anxiety, especially when separated from family members.
What Should the Owner Response Be?
Dog owners who remove the dog's favourite suckling object often find the dog chooses a substitute. The substitute may be an article of clothing or something not meant for the dog. While the dog appears to refuse to stop suckling, it is more of a compulsive behaviour. Do not encourage it, but do not try to stop the suckling either.
The Doberman Pinscher may suck on the skin at the upper part of the rear leg. This sucking habit can damage the skin. Gwen Bailey reports that some of this flank sucking behaviour has followed family lines and to be present in litter mates. Unlike object sucking, you should discourage flank sucking because it proves detrimental to the dog's health. Substitute a blanket that won't easily tear.
Wash the suckled item to keep it sanitary. Purchasing a duplicate of the blanket or toy can make the laundering easier..If you cannot purchase a duplicate suckling object, enlist the dog's help in taking it to the laundry room. Let the dog watch you put it in the washer. A dog who suckles will watch you move the blanket to the dryer and will be ready to find it with you when the dryer stops.
Science Daily reported in January 2010 that a gene related to flank and blanket sucking in dogs has been discovered. Through a collaboration between the Cummings School of Veterinary Medicine, the University of Massachusetts Medical School and the Massachusetts Institute of Technology, the gene is believed to cause canine compulsive disorder, similar to obsessive compulsive disorder in humans.