Animal behaviorist reveals what rescue puppies learn that pedigrees don't

Early Experiences Shape Behavior
Learning That Humans Are Predictable
Safety Cues Can Make a Difference
Learning How to Regulate Fear
Stability Teaches New Habits

Rescue dogs aren’t born different but many are forced to adapt far earlier than dogs raised in stable homes.

Without consistency, safety or predictability in their early weeks, many rescue dogs learn survival skills that pedigree dogs raised in secure environments often never need to develop.

Animal behaviorists say those early experiences can shape how dogs interpret people, environments and risk, often influencing behavior long after they leave shelters or unstable homes.

Newsweek spoke to Deby Cassill, an associate professor of integrative biology and animal behaviorist at the University of South Florida in Tampa, about what rescue dogs often have to learn and why those lessons don’t mean they are “damaged” or inferior.

According to the The American Society for the Prevention of Cruelty to Animals (ASPCA), about 2.9 million dogs entered shelters and rescues in 2024. Of those, approximately 2 million were adopted, 554,000 were returned to their owners, 334,000 were euthanized, and 524,000 were transferred to other organizations.

A stock image of dogs in a shelter kennel.

Early Experiences Shape Behavior

Cassill said rescue dogs are not biologically different from pedigree dogs, but their early experiences can leave lasting impressions.

She told Newsweek: “Puppies inherit breed-based predispositions such as herding reactivity, guarding behavior, scent-driven focus, etc. Between 3 and 14 weeks of age is a sensitive period during which social and emotional development is learned—good or bad.

“Dogs raised in stable, predictable environments during that window tend to develop secure expectations about humans and their surroundings,” she said.

Cassill explained that these dogs often have to learn how to adapt to everyday sights, sounds and routines that other dogs encountered naturally while growing up.

Learning That Humans Are Predictable

A stock image of a woman petting a dog in a shelter.

Cassill said dogs from unstable backgrounds may interpret sudden movements, raised voices or unfamiliar handling as threats.

Dogs that missed early socialization may resist grooming, nail trims or veterinary exams.

Everyday experiences such as elevators, glass doors, car rides and household appliances can feel overwhelming if they weren’t introduced early. Over time, however, gradual exposure and confidence-building routines can help reshape those responses.

Safety Cues Can Make a Difference

Cassill emphasized that safety cues play a critical role in helping rescue dogs feel secure.

“A predictable routine of feeding times, walks, sleep cues; consistent verbal markers such as, you’re safe, good, and calm stroking along the shoulders or chest; providing a refuge or safety place like a mat or bed or crate that the dog can to retreat to.

“Dogs are den animals—a cage is naturally perceived as a safe space,” she said.

Calm, consistent responses from owners can help dogs learn that stress does not always signal danger and that humans can be trusted.

Learning How to Regulate Fear

Some rescue dogs develop hypervigilance meaning they are constantly scanning their environment, startling easily or reacting defensively.

Cassill said gradual exposure to normal stimuli, paired with safety cues, can help retrain how dogs interpret potential threats.

She told Newsweek: “Dogs who have experienced abandonment may either cling intensely (separation anxiety) or avoid bonding entirely before accepting touch, eye contact or close proximity.

“They need to learn all of the above. Trust for some rescue dogs takes time. Respecting their pace is essential.”

Stability Teaches New Habits

A stock image of a dog playing on the couch with a blanket.

Cassill said genetics still play a role in every dog’s behavior, regardless of background.

“All dogs are born with a genetic predispositions shaped by breed history (for example, high drive in herding breeds, guarding instincts in protection breeds) that can make some dogs more difficult to train if those traits are mismatched with their environment,” she said.

However, she stressed that rescue dogs are not inherently harder to train or less capable than pedigree dogs raised in stable homes. Instead, many simply need structured learning to replace early survival strategies with more secure, socially adaptive behaviors.

“In general, rescue dogs are not inherently more difficult or less capable than pedigree dogs raised in stable homes. But, they often need structured learning to replace early survival strategies with secure, socially adaptive behaviors,” she said.

According to Cassill, patience and consistency are key. With stable routines, clear cues and time to build trust, most rescue dogs can become loyal, confident companions.

The lessons they had to learn early may be different—but they are not a disadvantage. In many cases, they reflect resilience rather than risk.

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