Most aggressive dog breeds: Is your pooch on the list?

Updated: May 6, 2021 / 12:41 PM CDT

(NewsNation Now) — Smaller, older and male dogs are most likely to growl and be aggressive than other dogs, according to a study of 23 different dog breeds.

Scientists at the University of Helsinki studied the behavior of more than 9,000 dogs to assess aggressive behavior.

Some breeds are more likely to be aggressive, resorting to biting or snapping attacks, than others. The study, published in Scientific Reports, found that Rough Collies were the most aggressive breed. Miniature poodles, miniature schnauzers, German shepherds and Spanish water dogs were also found to be more aggressive.

This graphic was included with the study "Aggressive behaviour is affected by demographic, environmental and behavioural factors in purebred dogs" from researchers at the University of Helsinki, published May 3, 2021, in Scientific Reports. — This graphic was included with the study “Aggressive behaviour is affected by demographic, environmental and behavioural factors in purebred dogs” from researchers at the University of Helsinki, published in Scientific Reports.,

Even-tempered Labrador Retrievers and Golden Retrievers were found to be the least aggressive.

Scientists found male dogs are more aggressive than females, and neutering them has no impact on making them more or less aggressive. In addition to size and sex, the study also looked at age and fearfulness as factors in aggressive behavior.

The study also found that dogs are more likely to be aggressive if they are the owner’s first dog.

You can read the full study below:

NewsNation affiliate KTLA contributed to this report.