Can Aggression in Dogs Be Linked to Environmental Toxins?

A new study published in the Iranian Journal of Veterinary Science and Technology investigated whether heavy metals in the bloodstream could be associated with behavioral problems in terriers. Researchers measured levels of lead, mercury, arsenic, and cadmium in dogs with and without behavioral issues.

Most results showed no significant differences. However, one stood out:

Dogs showing aggression toward their guardians had significantly higher levels of cadmium in their blood. This link was not observed with other forms of aggression.

Where does cadmium come from?

• Contaminated low-quality food (especially organ meat or ingredients from industrial areas)

• Water from untested sources

• Air, dust, and soil in polluted regions

• Cheap toys or accessories with toxic dyes

  
  

Cadmium accumulates in the body, particularly in the kidneys and liver, and has neurotoxic potential.

The authors emphasize that this is a preliminary finding, and more research is needed. But it opens up a new perspective on how environmental factors—not just trauma, socialization, or genetics—may influence behavior.

It’s another strong argument for taking a holistic approach to canine behavioral issues—one that includes emotions, experiences, physiology, and environmental toxins.

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Source:

Bayazi, R., Heidarpour, M., Azizzadeh, M., & Khoshnegah, J. (2025). Concentration of blood heavy metals in terrier dogs with some common behavior problems. Iranian Journal of Veterinary Science and Technology. https://doi.org/10.22067/IJVST.2025.90435.1434