Neurotransmitters are chemicals that are released by the axon of neurons in the brain (the brain cells responsible for transmitting information). These chemicals transmit signals across the synapse from one neuron to another and can change the way another neuron responds by either exciting or inhibiting the message. Three neurotransmitters important in understanding behavioural responses in dogs are noradrenaline, dopamine, and serotonin.
Noradrenaline, also called norepinephrine, deals with responses to stress, danger and/or threats. It stimulates the central nervous system to trigger arousal, alertness, vigilance, and attention in the presence of a trigger. When a dog is confronted with something that makes it uneasy, this is the chemical that guides its attention to it and puts the dog on alert. When the fight or flight response is triggered and the sympathetic nervous system is activated, noradrenaline is released. The body’s heart rate and breathing rate increases and there is an increase in blood glucose levels (to provide energy to muscles in the case that ‘flight’ needs to occur). Chronic exposure to high levels of noradrenaline can result in gastrointestinal difficulties, anxiety, and muscle tension.
Dopamine works with the prefrontal cortex and helps with behaviour modification as it is a ‘feel good’ chemical that also plays a part in motivation. “Low levels of dopamine make people and other animals less likely to work for things, so it has more to do with motivation and cost/benefit analyses than pleasure itself.” (Buckley, 2012). A dog with low dopamine levels may be very quiet, less inclined to initiate movement, and seem depressed. Increased levels of this neurotransmitter increase the motivation level in a dog and make positive training possible as it drives a dog to repeat rewarded behaviour. Finding rewards that our dogs absolutely love can make modifying behaviour much easier. Using a favourite toy or an especially tasty type of treat or food when working with a stressed, anxious, fearful or reactive dog and help to increase dopamine levels, reduce stress and push the dog to continue trying a task or behaviour.
Serotonin is responsible for emotional states, bonding behaviours and regulates mood balance alongside the hypothalamus. It also plays a role in regulating heart and lung function, sleep-wake cycles, behaviours, awareness of pain, appetite, body temperature and movement. This neurotransmitter can be affected by diet, which has a direct impact on an animal’s mood. Nutritionally derived serotonin is something the body relies heavily on, so a poor diet that lacks tryptophan results in lower serotonin levels and increased mental instability. In many species, dogs included, depletion of serotonin in the body has been linked with aggression. Increasing serotonin in these cases may help to decrease the aggressive behaviour, as it has a strong inhibitory effect on emotional responses and impulsive behaviour, alongside positive behaviour modification techniques. The use of positive behaviour modification techniques is important as serotonin also “directly attenuates the subjective experience of pain occurring during highly emotional displays involving anger or aggression, thereby mitigating against the effectiveness of physical punishment in the control of emotionally charged (affective) aggression.” (Dog Behaviour).
Too much serotonin in the body can result in ‘serotonin syndrome’ which is a potentially life-threatening condition caused by exposure to antidepressant medication given at incorrect levels. Because serotonin impacts so many of the body’s systems, symptoms of serotonin syndrome include: diarrhea, tachycardia (rapid heart rate), rapid breathing, increased body temperature, high blood pressure, trembling, seizures, difficulty walking, rigid muscles, confusion, depression, hyperactivity, lethargy, agitation or aggression, behavioral abnormalities, temporary blindness and comas. If treatment is given quickly (within half an hour of noticing symptoms, activate charcoal can be digested to help absorb the antidepressant and reduce the amount that is taken up by the dog.
It is important that the levels of these neurotransmitters are kept in proper balance to ensure stable behaviour. Keeping a dog’s stress levels low, setting up an environment for them that promotes a general calm state of mind and ensuring that they are receiving proper nutrition can help in optimizing the roles of these neurotransmitters in the body.
Integrating activities from the Calmness Triad in to your dog's everyday life can greatly help in managing stress levels, which in turn promotes good health.
Photo courtesy of Absolute Dogs
1) Passive Calming activities are enrichment activities that your dog can largely enjoy on their own. Providing things like snuffle mats, frozen kongs, stuffed bones, long-lasting chews, puzzle toys and scatter-feeding opportunities are great ways to keep your dog busy in a calm and productive way.
2) The Calmness Protocol involves rewarding your dog's choices to just do nothing.Watch for times when your dog is choosing calm behaviour (lying in their crate, snuggling up on the chesterfield with you, going to another room for some quiet nap time) and reward them calmly and slowly with a treat or some of their daily food allowance. See how quietly you can do this - be ninja-like! Can you leave a piece of food next to your sleeping dog without them waking to eat it immediately? If you can, you've really caught a calm moment:-)
3) Active Rest is as important for our dogs as it is for us, and often (especially with very young dogs) being over-tired leads to a variety of unwanted behaviours, such as increased barking, nipping, chewing inappropriately and rowdiness. We get grumpy when we haven't had enough sleep, and so do our dogs. Making sure that they have a quiet place to rest, away from the activity in the household is important...this could be a crate, a puppy pen, a soft bed, or just a spot on a bed or chesterfield in another room.
If you are interested in learning more about how to help promote a healthy, calm, mental state in your dog, check out the Canine Calmness Workshop below:
Canine Reactive Behaviour Coursebook by Canine Principles, 2019
Canine Anxiety Coursebook by Canine Principles, 2019 2019
Canine Fear Coursebook by Canine Principles, 2019
Serotonin Syndrome in Dogs: Symptoms, Causes and Treatments:
Dopamine Not About Pleasure Anymore (Buckley, 2012):
Neurotransmitters Implicated in Dog Aggression:
Neurotransmitters and Behaviour: Dog Behaviour (2020):