Can I tell if my puppy is going to be aggressive when he grows up?


Perhaps. Early risk factors for aggression include fearfulness, small body size, and, believe it or not, being an owner’s first dog. 

I spoke with veterinarian Catherine Barnette about a recent study published in Scientific Reports in May 2021. The study looked at this exact FAQ, and Dr. Barnette summarizes, “Aggression is a significant problem in pet dogs and this study aimed to identify risk factors for aggression. Risk factors include fearfulness, small body size, male sex, lack of other dogs in the home, and being an owner’s first dog.” 

Let’s take male dogs, for example. This study showed that male dogs had higher odds of aggressive behavior than female dogs. This association has also been found in previous studies, but the specifics are a bit nuanced. For example, one study found that female dogs were more likely to have bitten than male dogs. All this is to say, more studies are needed to identify distinguishing correlations. 

I found the “being an owner’s first dog” factor particularly interesting, as it’s not exactly self-explanatory. Here’s what the study had to say about that factor, “It is possible that experienced owners are more aware of the importance of socialisation. Previous experience can also help owners to identify a problem at [an] early stage, when the problem can be treated more efficiently. Furthermore, if the owners had problems with their first dogs, they may be more careful when choosing a new dog.”

Dr. Barnette concludes, “If your dog falls under any of the risk factor categories listed above, take note and consult with a trainer if you think your dog has aggression issues.”

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