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At What Age Should Puppies Be Brought to Their New Homes?

Early separation of a puppy from its litter results in later behavior problems.

Alfred William Strutt/ Public Domain
Source: Alfred William Strutt/ Public Domain

I was speaking to a well-respected breeder of Soft Coated Wheaten Terriers and mentioned to her that I had picked up my new puppy from his breeder at the age of nine weeks. She looked at me with some amazement and said, "Nine weeks? That is leaving the puppy in its litter for an awfully long time. The scientific data says that the optimal time to send a puppy to its new home is at seven weeks — 49 days to be precise. I never let a puppy go much earlier than that, regardless of a buyer pressuring me to let a puppy go at age six weeks, but I do try to get the puppies adopted as close to seven weeks as possible. Socially speaking, the litter is a competitive environment. If the puppies stay in the litter too long they start to develop a pecking order and a strong pattern of dominant or submissive behaviors around their littermates. These carry over when they leave and can be a source of social and behavioral problems later on."

The underlying psychological issue about what age to bring pups home involves socialization. You can think of socialization as a process where the dog learns how to deal with the living things in its environment—specifically dogs and people. The scientific foundation for our knowledge of socialization in dogs begins with the classic book by John Paul Scott and John Fuller that was published in 1965*. It summarized 13 years' worth of research which was done at the Jackson Laboratories in Bar Harbor, Maine.

According to that research the "socialization period" starts at three weeks and extends to week 14. It is during this period that puppies learn to be dogs. As they play with their littermates they mimic fighting, hunting, catching, sexual activity, and guarding behaviors. It is in this way that the pups develop the skills they will need later in life. They learn the behaviors associated with dominance and submission, and also basic communication skills at the same time. If they are bred in an environment where they have frequent interactions with humans, they also learn to associate with and bond with people.

The suggestion is that socialization of dogs with other dogs comes first (from three to six weeks), and socialization of the dogs with people comes next (from six to 14 weeks). If puppies do not have a chance to start socialization during these time periods then the chance that the dogs will ever be properly socialized becomes small indeed. A poorly socialized dog is apt to be more fearful and will have difficulty fitting in the world of dogs or people, which means that it is not likely to succeed as either a pet or a working dog.

Scott and Fuller never explicitly say anything about seven weeks being an optimal time to take a dog out of its litter, although they do comment that it is inadvisable to take a dog away from its litter before seven weeks of age. The conclusion that seven weeks of age is an important marker seems to come from comments made by Clarence Pfaffenberger, the guiding force behind guide dogs for the blind, who felt that before seven weeks dogs were not trainable.

Pfaffenberger's conclusion was picked up by Richard Wolters, a popular dog writer during the 1960s and '70s, who wrote that if you want to have an easily trained dog you should "buy your puppy and take him home at the exact age of 49 days." Perhaps because of Wolter's popularity and Pfaffenberger's prestige, these comments were accepted as scientific gospel by dog breeders around the world.

There is good evidence that the age a puppy is taken away from the litter and sent to its new home does make a difference. An Italian veterinarian and two researchers from the Faculty of Veterinary Medicine at the University of Milan recently published an article in the scientific journal Veterinary Record** that looked at what happens to puppies who are separated from their litter at an early or a later age. They tested 70 dogs who were separated from their litter and adopted between the age of 30 and 40 days (that is between the fifth or sixth week) and compared them to puppies that were adopted at 60 days of age (which is between the eighth and ninth week).

Questionnaires were sent to the owners of all 140 dogs when the dogs were adults between the age of 18 months and seven years. Very specifically the questionnaires asked about behavioral problems in the dogs. Their results were unambiguous — the dogs separated from their litter at an early age did not fare as well. The researchers summarize their results saying:

"The odds of displaying destructiveness, excessive barking, fearfulness on walks, reactivity to noises, toy possessiveness, food possessiveness, and attention-seeking were significantly greater for the dogs that had been removed from the litter earlier during the socialization period."

Furthermore, the effects were much greater in dogs purchased from pet stores who most likely had less opportunity to interact with people and other dogs regularly.

This research report clearly shows that early separation from the litter is bad for puppies and results for a higher incidence of problems when the dogs are adults, in all probability because taking them from the needed interactions before they are fully socialized interrupts their behavioral development.

Nonetheless, I was intrigued by this apparently well accepted notion that 49 days or seven weeks of age is the optimal time for a puppy to go to its new home. So I started an extensive literature search that extended to the 1940s and continued up to the present, covering all the veterinary and behavioral literature that I could access. I came up with not one single study suggesting that there is something special, or valuable about choosing seven weeks as the time to send a puppy to its new home.

I mentioned this to a friend of mine who is an established dog trainer and she laughed and suggested, "Well seven is a lucky number, and 7×7 gives you 49. So maybe this 49-day rule was chosen by breeders in the hope that it would give the puppy some good luck in his future life." I suppose that in the absence of scientific data her explanation makes as much sense as any other.

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* Scott JP & JL Fuller 1965 Genetics and the Social Behavior of the Dog. Univ of Chicago Press.

** Pierantoni, L., Albertini, M. & Pirrone, F. (2011). Prevalence of owner-reported behaviours in dogs separated from the litter at two different ages. Veterinary Record,169, pp. 468, doi: 10.1136/vr.d4967

See Coren's books including: The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome

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