Do supplements help aggressive dogs? (The Biochemistry of Angry)

7th March 2023
Beryl Shuttleworth
No Responses

The news lately has been full of stories about, in particular, pit bulls mauling humans. This is a horrible situation and has so many underlying causes and subtexts. I don’t want to go into the whole moral, ethical, training, genetic, behavioural and lifestyle dilemma here. I would like instead, to ask if there is any way a supplement could help the situation.

pit bull

What would the effect be of giving a pit bull a natural supplement? What does the science say?

The biochemistry of aggression

Biochemically, aggression in dogs is complicated. A solution which is often recommended to owners of aggressive male dogs is neutering. But studies on the relationship between testosterone and other androgens (male sex hormones) and aggression have been inconclusive1,2. Some dogs were even found to be more aggressive after neutering.3

Studies on the serotonin pathway are more consistent. Serotonin is the ‘happiness’ and ‘calmness’ neurotransmitter. Aggressive dogs have low serotonin levels. This is particularly true of the breeds known to be prone to aggression.4-8 For this reason, SSRIs (selective serotonin reuptake inhibitors, which increase the levels of available serotonin) are often prescribed.

How can we influence this aggression?

So, of course, me being me, would ask this question: Is there a way to decrease this anger response using diet or natural supplements?

With low serotonin seemingly being the main instigator of aggression in dogs, let’s look at ways to increase serotonin. Now, contrary to popular opinion, you don’t need fancy pharmaceuticals to do this. It can be very effectively achieved using these three safe, natural ingredients:


This one is easy. Tryptophan, an amino acid, is what your dog’s body uses to make serotonin. So, the more tryptophan in circulation, the more serotonin can be made. Happy, calm dog.


L-theanine is quite a magical amino acid. It increases both dopamine and serotonin production in the brain. It also increases GABA activity. GABA (gamma amino butyric acid) is called an inhibitory neurotransmitter. It is the policeman of the brain, down regulating all the excitable pathways. And then (this is the magical part) L-theanine directly influences brain waves, producing the same brain waves produced during meditation – alpha waves. So, it is a little shot of meditation for your angry dog’s brain.


Inositol is a B vitamin that has been shown to increase serotonin receptor sensitivity. At the same time, it also increases the brain policeman GABA, which blocks things like anxiety, stress and fear.


Are natural supplements going to change highly ferocious, reactive dogs into teddy bears? I doubt it. There are way too may other factors at play. But could these nutrients be another resource in the fight against fighting? Yes, I think so.

These three ingredients can be found (together with other calming natural ingredients) in our products Serenity Formula and Calming chews.


  1. Neilson J. C., Eckstein R. A., Hart B. (1997). Effects of castration on problem behaviors in male dogs with reference to age and duration of behavior. J. Am. Vet. Med. Assoc. 211, 180–182.
  2. Guy N. C., Luescher U., Dohoo S. E., Spangler E., Miller J. B., Dohoo I. R., et al. (2001). Demographic and aggressive characteristics of dogs in a general veterinary caseload. Appl. Anim. Behav. Sci. 74, 15–28. 10.1016/S0168-1591(01)00153-8
  3. Guy N. C., Luescher U., Dohoo S. E., Spangler E., Miller J. B., Dohoo I. R., et al. (2001). Demographic and aggressive characteristics of dogs in a general veterinary caseload. Appl. Anim. Behav. Sci. 74, 15–28. 10.1016/S0168-1591(01)00153-8
  4. Reisner I. R., Mann J. J., Stanley M., Huang Y., Houpt K. A. (1996). Comparison of cerebrospinal fluid monoamine metabolite levels in dominant-aggressive and non-aggressive dogs. Brain Res. 714, 57–64. 10.1016/0006-8993(95)01464-0
  5. Haug L. I. (2008). Canine aggression toward unfamiliar people and dogs. Vet. Clin. N. Am. 38, 1023–1041. 10.1016/j.cvsm.2008.04.005
  6. Rosado B., García-Belenguer S., León M., Chacón G., Villegas A., Palacio J. (2010). Blood concentrations of serotonin, cortisol and dehydroepiandrosterone in aggressive dogs. Appl. Anim. Behav. Sci. 123, 124–130. 10.1016/j.applanim.2010.01.009
  7. León M., Rosado B., García-Belenguer S., Chacón G., Villegas A., Palacio J. (2012). Assessment of serotonin in serum, plasma, and platelets of aggressive dogs. J. Vet. Behav. 7, 348–352. 10.1016/j.jveb.2012.01.005
  8. Amat M., Le Brech S., Camps T., Torrente C., Mariotti V. M., Ruiz J. L., et al. (2013). Differences in serotonin serum concentration between aggressive English cocker spaniels and aggressive dogs of other breeds. J. Vet. Behav. 8, 19–25. 10.1016/j.jveb.2012.04.003

Leave a Reply

Your email address will not be published. Required fields are marked *