Pet Store Puppies More Likely to Become Aggressive Dogs

Are you looking to avoid behavior problems with your dogs? Don’t get them from a pet store. That’s sound advice for a number of reasons, but it’s also backed by a new study from the University of Pennsylvania.

Researchers from U Penn have found evidence that pet store puppies have a higher risk for behavioral problems once they reach adulthood.

The research paper, published in the May 15 issue of the Journal of the American Veterinary Medical Association, was a collaboration between researchers at the Penn School of Veterinary Medicine, Best Friends Animal Society in Utah, and the University of Prince Edward Island’s Atlantic Veterinary College.

The Penn team also worked together on a similar study in 2011 which saw bigger psychological problems in adult dogs that were rescued from commercial breeding facilities, better known as puppy mills.

Since most puppies in pet stores are obtained from puppy mills, researcher Frank McMillan wanted to see if they saw the same behavioral issues. They measured 14 behavioral variables and the pet store dogs were worse in 12 of them and only matched other dogs in the remaining two (rather than exhibiting better behavior).

“The results are pretty dramatic,” said McMillian. “The problems span so many different types of behaviors, and the differences are rather extreme for some of the behaviors.”

For instance, pet store dogs were at higher risk for being aggressive toward their owners and other dogs. The reasons for bad behavior are fairly logical and parallel to what you might expect from similar scenarios in humans. That is, if a child is brought up in a high stress environment, they just might end up having long-lasting psychological issues.

Puppy mill and pet store dogs are not properly socialized and live a hectic and disruptive early life. Earlier research has suggested that stressful pregnancies for the mothers lead to psychological issues for her offspring. The stress may play a role in improper fetal brain development.

(image by David Fisher via Wikimedia Commons)

Also see:

Kristen Stewart’s Mom Has Wolf-Dog Hybrids

5 Potentially Tragic Dog Behavior Myths


Fred Hoekstra
Fred Hoekstra4 years ago

Thank you Jason, for Sharing this!

Carrie-Anne Brown

thanks for sharing :)

Nanette A.
Nanette a4 years ago

Poor poochies. I don't understand how people can run puppy mills. There needs to be stronger laws when it comes to any one who has puppy mills or is abusive in any way toward animals.

Silvia Saletti
Silvia Saletti4 years ago

ADOPT, ADOPT, ADOOOOOOPT! Puppy mills should be abolished by law!!

John S.
Past Member 4 years ago

Makes since thay tend not to be socialised properly when a puppy, and anyone buy from a pet store probably doesn't do a great job, and so many people buy a dog as a dog and do not realise that breeds are different.

Boo Boo
Boo B4 years ago

I don't buy dogs. Mutts from someone's farm have ALWAYS been the best.

Jane Williams
Jane Williams4 years ago

Why am I not surprised? Don't shop, adopt!

Ryan Surfs
Past Member 4 years ago

Hate puppy mills.

Jeaneen Andretta
Past Member 4 years ago

When these poor furry babies start from a very unkind place like a puppy mill, how can you expect them to be well adjusted. If you did buy one please be very patient and gentle with the poor little puppy, it is not its fault.

Lydia Weissmuller Price

Garbage. The reason to not purchase from pet shops is to prevent abuse of the animals by unscrupulous puppy mills and dealers. There is nothing inferior in these dogs aside from physical defects that are caused by excessive breeding of the mother and in- and close line-breeding. Many marvelous pets have had their beginnings in pet shops, puppy mills, abusive homes, and even dog-fighting operations. Dogs born in and rescued from war zones have made wonderful companions (talk about stress). Please don't incite discrimination against ANY dog, whether due to its breed or upbringing. Where do you think shelter dogs come from? They are the result of puppy mills! And they go on to become someone's best friend. There are very few emotional scars that cannot be healed by a huge dose of love and understanding from the right individual, some simply take more time than others. Human beings have risen above their circumstances and horrendous beginnings in life to become great leaders and humanitarians. Others have had decent childhoods and grown to be serial-killers. Attitude is everything, and it is a dog's nature to be devoted and have a desire to please. By all means, adopt from shelters and rescue those on death row. But don't imply that ANY dog is inferior to another. EVERY dog is a bundle of love wrapped in fur that travels on four legs. They simply need someone to help them realize their full potential. There is no perfect life...there's just life, and the one you love is perfect f