Pet dogs that have anxiety exhibit neurological abnormalities that mirror those seen in people with mental health issues, new research has revealed. These findings may have major implications for the treatment of canines with emotional distress while also shedding light on the neurology of anxiety-related disorders in our own species.
To reach these conclusions, the study authors conducted brain scans on 38 pet dogs using non-invasive functional magnetic resonance imaging (fMRI). Meanwhile, pooch participants’ owners completed the so-called Canine Behavioral Assessment & Research Questionnaire in order to help the authors assess each dog’s anxiety level.
Overall, 13 dogs were classified as anxious while the remaining 25 were designated healthy. The researchers imaged the animals’ brains while they were at rest, thus enabling them to observe general differences in functional brain connectivity between the two groups.
In general terms, anxious dogs displayed stronger neural connections between the amygdala and other regions of the brain’s anxiety network. “We detected higher connectivity between amygdala-hippocampus, amygdala-mesencephalon, amygdala-thalamus, frontal lobe-hippocampus, frontal lobe-thalamus, and hippocampus-thalamus, all part of the anxiety circuit,” write the study authors.
This is significant because the amygdala and hippocampus are associated with memory, arousal, excitement, and fear in both dogs and humans. “Dysfunctions of these regions can lead to anxiety symptoms like more fear, less excitability, less trainability and so on,” say the researchers.
Explaining their data in layman’s terms, the authors say that “there is better communication efficiency between these regions and the rest of the network when confronted with anxiety.” This, in turn, backs up a “well-accepted hypothesis” linking anxiety disorders with “increased or overactive functioning in the salience network.”
When analyzing the brain activity patterns behind specific traits like aggression, fear, and trainability, the researchers found a number of interesting parallels between nervous dogs and anxious humans. For example, excessive attachment or attention-seeking was associated with altered connectivity within the thalamus, which matches up perfectly with previous research on anxiety in people.
Likewise, dogs that pathologically chase or are particularly aggressive towards other dogs showed alterations in the frontal lobe, which is in line with previous studies linking dysfunction in this part of the brain with depression and anxiety symptoms in humans.
In an email to IFLScience, study author Yangfeng Xu explained that “the anxiety dog brain study is the base for our further research. We want to use transcranial magnetic stimulation (TMS) [to treat] anxious dogs in the future.”
“By knowing more about the mechanisms of anxiety in dogs, we can have better understanding in applying TMS in dogs. From a future clinical viewpoint, the results of our study are therefore relevant for the treatment of patients with anxiety disorders in both human and veterinary medicine.”
Animal models of neuropathology are valuable as they provide some insight into how mental health issues may manifest in our own brains. Most research on this topic involves rodents, although studying dogs allowed the authors to observe how anxiety plays out in the brain of a species with a larger cortex.
Overall, the researchers say their findings “provide important insight into pathophysiological mechanisms of anxiety in dogs, which can lead to more personalized and effective therapies, and together with other animal research, build a bridge to the understanding of human behavior (and vice versa).”
The study is published in the journal PLOS ONE.
