Dog bites occur more frequently in hot weather and when air pollution is high

Dog bites could be more frequent — even up to eleven percent more — on days that are both hotter and sunnier. This trend is also seen on days when the levels of air pollution are high.

This intriguing connection was suggested by a study published in the journal Scientific Reports. The authors, however, have advised caution, stating that there’s a need for more data and additional research to validate these findings.

Earlier research has already shown that both hot weather and increased air pollution can be linked to heightened aggression in humans and several animal species including Rhesus monkeys, rats, and mice. But, until now, it was uncertain if the same trend applied to dogs being aggressive towards humans.

Studying dog bites in major US cities

To investigate this, a team led by Clas Linnman meticulously studied the data related to dog bites in eight major US cities — Dallas, Houston, Baltimore, Baton Rouge, Chicago, Louisville, Los Angeles, and New York City.

This data, dating from 2009 to 2018, was either acquired from publicly accessible records kept by animal control authorities or sourced from previous compilations of dog bites.

In this decade-long span, there were 69,525 reported incidents of dog bites. This boils down to an average of three dog bites each day.

The team then explored the correlation between these dog bite rates and daily levels of fine particulate matter (PM2.5), ozone, and temperature. They also looked into the UV and precipitation levels on those days.

What the researchers learned about dog bites

From their analysis, the authors found that on days with increased UV levels, the occurrence of dog bites increased by eleven percent. Likewise, days with higher temperatures saw a four percent rise in dog bite incidence. Days with increased levels of ozone saw a three percent increase.

Interestingly, dog bites were one percent less likely on days with more rainfall. However, they found no changes in the dog bite rates on days with higher levels of PM2.5.

Team expresses need for more research

The authors did put forth a note of caution, explaining that the data they had on dog bites lacked details about other factors that might influence a dog’s likelihood of biting.

They didn’t have access to information such as the breed or sex of the dog, whether the dog had been neutered or spayed, or prior interactions between the dog and the individual bitten, such as familiarity.

Wrapping up their report, the authors concluded that their findings seem to extend the known association between higher temperatures, increased air pollution, and aggression across species. This study now adds dogs to the list. However, they stressed the need for further research to not only confirm this finding but also explore this relationship in depth.

More about hot weather and aggressive behavior

It’s fascinating how the weather can influence human behavior, including levels of aggression. This concept isn’t new; in fact, it has been studied extensively. Several factors are believed to contribute to why hot weather might lead to an increase in aggression.

Discomfort and Irritability

Heat can cause physical discomfort which can lead to increased irritability. The unpleasant sensation of being hot and sweaty might make people more likely to lose their patience and become angry. This might also be worsened by poor sleep quality, another side effect of hot weather.

Changes in Brain Chemistry

There’s some evidence to suggest that exposure to heat may lead to changes in brain chemistry. These changes can potentially influence behavior, including making people more prone to aggressive actions. Heat stress might stimulate the production of certain hormones, like cortisol, which are associated with stress and aggression.

Heat Hypothesis

This is a theory that connects higher temperatures to increases in aggressive behaviors. The premise is that heat influences the levels of arousal, which can make people more reactive and less able to control their aggressive impulses.

Routine Activities Theory

This theory posits that during warm weather, people are more likely to be outdoors and interact with each other, which increases the chances for conflict and potentially aggressive encounters.

While it’s clear that there’s a correlation between hot weather and increased aggression, it’s important to note that heat isn’t the only factor that can influence aggressive behaviors. Individual personality traits, the situation, and other environmental factors can also play significant roles.

As with all research, these findings have limitations and it’s important to remember that correlation does not necessarily imply causation. In other words, while there is a relationship between hot weather and aggression, the heat doesn’t directly cause the aggression. It’s likely a contributing factor among many others, and more research is needed to fully understand the connection.