my puppy has become “aggressive.” why now?

i am often asked the question, by adolescent/young adult dog parents, “why has my dog started to bark, or show outward signs of fear/distress/aggression (growl, lunge, etc.) now, when they seemed so perfect the first 10-12 months of their lives?”


this is my answer ~


when dogs are puppies they are taking note of all the things in their world, from what it feels like to be touched, to the sound of a motorcycle outside, to the look of a lady in a hat on a walk. they have a “file cabinet” in their brains, if you will, that is categorizing every single experience they are having in life, placing these “notes” in different files. one file might read “i like this,” and another “i don’t like this.”


when they are babies, they tend to be more stoic, or simply shy away from things they don’t like (hiding behind your leg, cowering or simply shutting down), but don’t be fooled, even though they may not be showing blatant signs of anything “negative,” they are filing things away. and they are doing it on a grand scale. those little brains are working every second. taking note of everything.


in general, when they are under five months of age, we won’t see much growling, barking, etc. (i say “in general,” but there are exceptions). this is sort of where we get into trouble. we say to ourselves, “oh, my puppy is okay. they are not showing any signs of anything.” so we go on, and ignore *socialization and **habituation.


then they reach adolescence and things start to change.


when they reach this stage, they pull up those files, read the ones that say “i don’t like this,” and start to be more overt about what they don’t like/what scares them. this is the time growling, barking, etc. starts to happen, and often gets worse as they move into young adulthood, from 10 -24 months of age (i believe this is why so many teenagers are dumped at the shelter).


this is why it’s so very important to socialize and habituate your puppy to every single thing in their lives, always coupling every single experience with something good. “thing” = treat/toy, whatever puppy/dog loves.


i must reiterate, exposure is NOT enough. these experiences must be paired with something yummy/good/fantastic.


it’s also very important that we do not take anything for granted. just because a puppy “seems okay” with everything in their lives, we cannot gloss over those things, and assume they will always be okay. we have to keep up the work, and continue our socialization protocol (item = treat) throughout their lives.


doing so is well worth it, and will help insure your dog has a happy/healthy life.


*socialization can be described as the process whereby an animal learns how to recognize and interact with the species with which it cohabits (david appleby, association of pet behavior counselors).


**habituation can be described as the process whereby an animal becomes accustomed to non-threatening environmental stimuli and learns to ignore them (david appleby, association of pet behavior counselors).