The age-old question of nature versus nurture holds especially true in the animal world and, more particularly, in your dog. Many factors in your dog’s early life can influence their overall mental, emotional, and physical health. For example, a giant-breed puppy fed an incorrect diet can experience lifelong bone and joint issues. Early development also can permanently affect your dog’s behavior traits. For example, anxiety, fear, and reactivity can be inherited traits that are only strengthened through environmental conditions. This reasoning makes it critical to do your research on prospective breeders if you’re planning on purchasing a specific breed, to ensure you find a mentally and physically healthy puppy.
Read on to learn the early factors that can influence your dog’s behaviors, including maternal stress and genetics, to socialization and fear periods.
How maternal and littermate influence shapes your dog’s behavior
Overall, three main areas are influenced by a puppy’s mother and their littermates—behavior traits, training and intelligence, and stress and reactivity.
- Behavior traits — Littermates affect a puppy’s future behavior traits more than their mother. A study that looked at German shepherds determined that littermates had a substantial influence on playfulness, chase-proneness, curiosity/fearlessness, and aggression. This study also concluded that the mother had little influence on her pups, either genetically or environmentally.
- Training and intelligence — Puppies left with their mothers for an extended period, rather than the typical eight weeks, appear to learn more quickly and have a higher performance rating, especially if they’ve been watching their trained mother work at searching for narcotics. This study showed that puppies who were weaned and separated from their trained mothers at 6 weeks of age, and those left with an untrained mother until they were 12 weeks old, had significantly lower performance ratings when tested as adults.
- Stress and reactivity — A stressed mother dog has high levels of cortisol that can cross the placental barrier and affect her unborn puppies. As their brains develop, they take in the signals wrought by the excess cortisol, and learn that their environment is not a safe place. Once born, these puppies have a cortisol level that increases more than normal in response to stressors and takes longer to return to a normal level. Essentially, these fearful puppies have a stress system that is tuned higher, and are always prepared for stressful events that may never come.
How early nutrition shapes your dog’s behavior
A main component of a healthy diet for mother dogs and their puppies—before and after birth—is docosahexaenoic acid (DHA). DHA is vital for brain development, and can help improve puppies’ learning ability. One study found that a dog fed a high level of DHA while pregnant, coupled with a high-DHA diet fed to the pups after birth, resulted in better results on an object recognition test.
How socialization and fear periods shape your dog’s behavior
During a puppy’s first year of life, they go through three stages—a primary phase from birth to 3 weeks, a socialization period from 4 to 14 weeks, and an enrichment phase from 15 weeks to 1 year. Small amounts of stimulation and stress during the primary and socialization phases lead to a calmer, less reactive dog. Puppies who do not receive proper socialization during this critical time can be unprepared to cope with daily stressors as adult dogs. However, you must be careful not to overstimulate your puppy at this sensitive age. Also, avoiding negative socialization experiences, such as being attacked by a large dog, kicked by a horse, or falling down a flight of stairs, is critical, because they can create a permanent negative association. Socialization during adulthood provides limited benefits for dogs.
Fear periods can also affect your puppy’s behavior once they reach adulthood. The first fear period occurs around 8 to 11 weeks of age, while the second typically occurs during adolescence, sometime between 8 and 14 months. During these fear periods, you may notice your puppy becoming unusually shy and fearful of new situations, and sometimes familiar people and pets. Tread cautiously during this time to create positive experiences for your puppy.
How the environment shapes your dog’s behavior
Early handling and exposure to different environments can help your puppy learn to be resilient and non-reactive as an adult. One study investigated multiple litters split in half and raised in separate locations, with one half raised in a professional breeding kennel, and the other half with their owners in a family atmosphere. The puppies who lived in the family environment demonstrated calmer behavior and an eagerness to explore their surroundings, rather than fearful or agitated behavior.
Because many dog owners have busy lifestyles with long work days, pets are often left alone for a large chunk of the day. These puppies and dogs, who only occasionally leave the property and seldom interact with other canines or people, often develop differently. Many suffer from a lack of exposure, stimulation, and socialization, which causes loneliness and boredom that can manifest in chewing, digging, anxiety, fear, and reactivity later in life.
While early factors can influence many of your dog’s later behaviors, that doesn’t mean there’s no hope for an anxious, scared, or reactive pet. Contact our Star of Texas Veterinary Hospital team to schedule a behavior consult, so we can help your dog live their best life.