Canine aggression and genetic control

For his doctoral thesis, Jørn Våge has studied genetically controlled behavioural aspects in dogs, with particular focus on aggression.

Behavioural problems in dogs, particularly aggression towards people, are often the reason why otherwise healthy dogs are put down. Aggression and anxiety-related behaviour also has a negative effect on animal welfare because stress influences both the mental and physical health of dogs.

Different breeds of dog with various forms of specific behaviour act as genetic isolates and are therefore suited for use in studies of complex characteristics such as behaviour. Similarities in diseases in dogs and humans also provide good opportunities for comparative studies in the field of medical genetics and dogs can therefore be valuable genetic models for various human disorders.

The central nervous system and its neurotransmitters and intricate networks of receptors play a key role in this study of behavioural genetics. Serotonin and dopamine are neurotransmitters in the brain and have an important function in the control of behaviour. Many of the medicines that are used for the treatment of psychological disorders have an effect on these neurotransmitters.

The neurotransmitter systems have many different receptors and enzymes that regulate the production and breakdown of psychoactive substances. All stages of these reactions are controlled by genes and can be potential sources of behavioural changes.

The doctoral study has revealed a variation in genes related to serotonin and dopamine in dogs. Våge used these variations as markers in the study and discovered connections between individual variants of genes and aggressive behaviour in dogs.

The thesis also covers studies of genetic activity (expression studies) in different areas of the brain in aggressive and non-aggressive dogs respectively.