Cortisol levels

What is cortisol?

Cortisol belongs to the glucocorticoids, a group of steroid hormones that are produced in the adrenal cortex. Cortisol is mainly released in response to stress, but is also influenced by other factors such as the time of day, hunger or illness. Cortisol has many effects on the body, for example:

• It increases blood sugar levels by stimulating gluconeogenesis (the formation of glucose from other substances) and inhibiting glucose uptake into the cells. This provides the body with energy to cope with stress.
• It suppresses the immune system by reducing the release of inflammatory mediators and decreasing the activity of immune cells. This prevents an excessive immune response that could lead to tissue damage.
• It influences the water and electrolyte balance by promoting the excretion of sodium and water via the kidneys and inhibiting the reabsorption of potassium. This helps to regulate blood pressure and increase blood volume.
• It modulates behavior by influencing mood, anxiety, learning ability and memory. Cortisol acts on various brain regions, such as the hippocampus, the amygdala and the prefrontal cortex.

Cortisol is therefore a vital hormone that helps the body to adapt to stress. But as with many things, the same applies here: Too much or too little is not good.

How do you measure cortisol levels in dogs?

Cortisol levels in dogs can be measured in various ways. The most common methods are:

• The determination of cortisol in blood serum. This is a simple and quick method, but it has some disadvantages. Firstly, the cortisol level in the blood can fluctuate greatly depending on when the blood sample is taken and how stressed the dog is. Secondly, the cortisol level in the blood can be influenced by other factors such as medication or illness.
• Determination of cortisol in the urine. This is a somewhat more complex method, but it gives a better overview of the average cortisol level over a longer period of time. To do this, the dog must collect urine over 24 hours, which is not always easy. In addition, the urine must be cooled and sent to the laboratory quickly.
• The determination of cortisol in saliva. This is a relatively new and promising method that has several advantages. Firstly, it is non-invasive and stress-free for the dog, as only a cotton swab is placed in the mouth. Secondly, it reflects the free cortisol level, i.e. the part of the hormone that is not bound to proteins and is therefore biologically active.

Which method is most suitable depends on the purpose of the measurement. For example, if you want to know whether a dog is suffering from adrenal gland disease, a blood test may be useful. However, if you want to know how stressed a dog is in everyday life, a saliva test may be better.

How do you influence cortisol levels in dogs?

Cortisol levels in dogs can be influenced by various factors. Some of these are:

• Genetic predisposition. Some dogs are naturally more susceptible or resistant to stress than others. This depends, among other things, on the activity of the hypothalamic-pituitary-adrenal axis, which controls hormone secretion.
• Early imprinting. The experiences a dog has in its first weeks of life can shape its stress response for the rest of its life. Good socialization and habituation to different stimuli can help the dog to cope better with stressful situations.
• The environment. The environment in which a dog lives can raise or lower its cortisol levels. Too much noise, heat, cold, pain, fear or boredom can stress the dog. On the other hand, a pleasant temperature, a quiet place, a comfortable bed, toys, food and water can relax the dog.
• The diet. Diet can have an impact on cortisol levels by influencing blood sugar regulation and gut health. A balanced diet with high-quality proteins, carbohydrates and fats can help dogs keep their blood sugar levels stable and support their gut flora. In addition, certain supplements such as omega-3 fatty acids, magnesium or probiotics can lower cortisol levels.
• Exercise. Exercise is an important factor for a dog's health and well-being. It helps the dog to burn off energy, build muscle, lubricate joints and release endorphins. However, exercise should not be too intense or too long as this can increase cortisol levels. Moderate exercise of about 30 minutes a day is optimal for most dogs.
• The bond. The bond between dog and human is one of the most important sources of safety and security for the dog. A good bond is based on trust, respect and love. It helps the dog to orientate itself towards its human and to be reassured by him. It also promotes the release of oxytocin, a hormone that has the opposite effect to cortisol.