November 26, 2018

Differences in serotonin serum concentration between aggressive English cocker spaniels and aggressive dogs of other breeds

At the School of Veterinary Science, Barcelona, a study was conducted to figure out if serotonin serum concentration was different in cocker spaniels than in other breeds, because cocker spaniels are known to be more aggressive and show impulse aggression. 

Aggression can be put into two categories: Affective (offensive and defensive aggression) and nonaffective (predatory aggression). Affective aggression is controlled by a handful of neurotransmitters, while nonaffective aggression is controlled by acetylcholine mainly.

Past studies on dogs and rodents have shown that a decrease in serotonin levels leads to an increase in aggression. In the cocker spaniel study, the mean serotonin level for cocker spaniels was 318.6, while the mean for non-cocker spaniels was 852.77, which is a significant difference.

Impulsiveness in both humans and dogs has been shown to correlate with lower serotonin levels, and this study helps prove that. Seratonin levels can come from a multitude of factors, and aggression in general in dogs is influenced by both nature and nurture, although this study belives that nurture is more important. Animals that spend their first days being nurtured by their mother are proven to have higher serotonin levels later on. Also, cocker spaniels are bought more often than other breeds in pet stores due to their popularity, and the stressful environment of a pet store on developing puppies can be an influence on levels of serotonin and tress, and behavior problems, in general, later in life.

In conclusion, the study shows that lower levels of serotonin probably influences aggressive behavior, but more research needs to be done on this breed to draw fully conclusive answers.


Summarized by Aidan Ryan, 11/26/2018