By Matt Bershadker, ASPCA CEO

With somewhere between 5 and 7 million homeless animals entering U.S. animal shelters, it’s unconscionable to suggest, as one writer did in the Washington Post, that adopting a pet from an animal shelter is a bad idea. (See a comprehensive refutation from Washington Humane Society’s Lisa Lafontaine.)

But as ridiculous as anti-shelter arguments are, they reveal destructive myths about shelter animals that need to be called out every time they arise. I’m sharing some of the most persistent ones below, and have enlisted help from ASPCA shelter science experts to help dispel them.

Myth: The major reasons dogs end up in shelters is because they were seized in criminal cases, or were too aggressive to own safely.

More than half of all dogs and cats in shelters were received as strays, but that doesn’t mean by any stretch they’re automatically aggressive, come from abusive environments, or have medical challenges. What’s much more important than an animal’s history is its current behavior and medical status. This information is typically well-known and shared by shelter staff who’ve been caring for the animal.

Myth: Shelter animals are not as clean as pet store animals.

Not only is this untrue, but the conditions of many breeding facilities or puppy mills (which supply pet stores that sell dogs) are nothing short of horrific. Puppy mill operators may fail to remove sick dogs from their breeding pools. As a result, puppies from puppy mills sometimes come with congenital and hereditary conditions including epilepsy, heart disease, kidney disease, and respiratory disorders.

Puppies born in puppy mills are usually removed from their mothers at just six weeks of age, denying them critical socialization, and housed in overcrowded and unsanitary wire-floored cages, without adequate veterinary care, food or water. Make no mistake: Anything purchased at a pet store that sells animals—even supplies—is keeping this vicious industry in business.

Myth: Older cats and dogs will not bond with new owners.

Again, simply untrue. Age is not a determining factor in an animal’s affection toward humans or its ability to bond with them. Just ask anyone who’s adopted an older pet, visit a shelter and ask to see their older animals, or simply look into the face of an older dog or cat. Organizations like Susie’s Senior Dogs are trying hard to connect more senior animals with loving homes. Believe me, they’re ready for you.

Myth: A shelter animal should never be given as a gift.

To the uninformed, this may makes sense, but data shows otherwise. A scientific study we published last October found that 96 percent of people who received pets as gifts reported it either increased or had no negative impact on their attachment to that pet. Also, 86 percent of the pets in the study are still in their homes, a percentage roughly equivalent to that in standard adoption.

The survey also showed no difference in attachment based on whether the gift was a surprise or known in advance. This is supported by previous studies conducted in the 1990s and 2000, which found that pets acquired as gifts are actually less likely to be relinquished than pets acquired directly by an individual owner.

This misconception is particularly harmful because it not only prevents shelter animals from going into loving homes, but may drive potential adopters toward pet stores that almost always get their inventory from puppy mills.

Myth: Adopting big or very strong dogs is a bad idea if you have little children.

There’s no evidence that big dogs are more likely than small dogs to harm children. Chances are, you already know some very sweet big dogs, and if you don’t, the ASPCA or your local shelter would be happy to introduce you to one.

There’s been some recent debate about the inherent natures of pit bulls in particular, but again, there’s no evidence to show that pit bulls are more likely to cause harm to humans than any other breed. A dog's—any dog’s—behavior is a function of many factors, including breeding, socialization, training, environment and treatment by owners.

Myth: Getting animals from breeders is safer because the breeders know the animal’s bloodline and family history.

First know that, as a result of their breeding, purebred dogs very often have genetic disorders and medical issue predispositions, certainly no less often than shelter dogs. Also, while bloodlines and histories are useful tools to assess an animal’s value, they are limited in terms of predicting behavior. On the other hand, shelters are motivated to save lives and make strong matches. Some use science and sophisticated tools to appropriately pair up animals and owners, and are happy to share everything they know about each animal.

Good breeders are focused not on profit, but on the health and welfare of the individual animals they handle, and we applaud that. But the plain truth is you’re helping to save and protect more lives if you make adoption your first option, so please match your open home and open heart with an open mind.