Could the pet food industry be affected by Brexit?

Effect of the Diet on Canine Aggression

As you probably know, dogs are pack animals and like to function as though in a hierarchy, even in the home environment. How are disputes about the hierarchy settled? Through aggression.

One of the main areas where disputes can arise is during feeding time. In the wild, the dominant members of the pack would eat first – getting at all the nutritious bits of their freshly caught prey. The subordinates? Well, they have to wait, and what do they get? Whatever is left. A tough life.

So what has this got to do with diet and aggression in the home environment?

Aggression at Home

Like I mentioned earlier, despite being domesticated for many, many years, dogs still retain a hierarchical view on life.

A lot of professional trainers and behaviouralist recommend that dogs are fed after you eat, to let them know you’re boss – because you’re eating first. Whilst this approach makes perfect sense, do dogs really compare a civilised gathering at the table with knives, forks, salads and manners to the barbaric tearing apart of a still-warm carcass?

Do dogs really compare a civilised gathering at the table with knives, forks, salads and manners to the barbaric tearing apart of a still-warm carcass?

A Closer Look at Diet Related Aggression

A study took a closer look at how dogs behave depending on their diet and the type of food they are eating – the results are quite interesting…

It showed that dogs display varying levels of aggression towards different types of food, below is the percentage of dogs in the test group that showed guarding-aggression towards each food item:

  • Rawhide chew 60%
  • Human food 50%
  • Bone 48%
  • Toy 48%
  • Biscuit 40%
  • Dog food 35%
  • Water 8%

The Effect of Protein in the Diet on Aggression

Dogs fed a high-protein diet showed a significant decrease in dominance aggression however an increase in aggression towards strangers. Dogs fed a control (normal) diet showed no change in aggression.

From this, it was concluded that; aggressive dogs should be fed a low-protein diet, this is in contrast to earlier suggestions that a high protein diet may improve behaviour.

A Tryptophan-Rich Diet Can Reduce Aggression

Diets high in tryptophan may reduce aggression, this is due to the fact that tryptophan is a precursor of serotonin. Serotonin is a neurotransmitter associated with the feelings of well-being and safety.

In normal protein sources, tryptophan is found in low concentrations, so by supplementing dietary tryptophan, it is possible to directly increase brain serotonin and thus induce a calmer mind set in the dog.

Tryptophan has also been shown to decrease aggression in chickens and primates too! Care must be taken when adding amino acids (such as tryptophan) to the diet, however, because an imbalance in amino acids and consequent anorexia could result.

Your Thoughts

How do you control your dog’s aggression? Have you ever tried giving a diet rich in tryptophan? Does your dog show guarding behaviour over their chews more than their food? Let us know you thoughts on the points raised in the article below.

About James Watts

BSc Bioveterinary Science. Editor of PetSci. When I'm not writing, learning, discussing, or reading about animals, you know it's the weekend! Currently developing PetSci HealthTrak, the fast and easy way to monitor your pet's weight and calorie intake. HealthTrak offers a simple way to track your pet's progress, helping them achieve a healthy weight and a long, happy life.

Check Also


Are Bigger Dogs Smarter than Smaller Breeds?

Correlation between brain size and intelligence isn’t straightforward. Humans are the most intelligent lifeform on …

dog wearing headphones

Dogs Enjoy the Sounds of Soft Rock and Reggae Music

Researchers at the University of  Glasgow explored how different music genres affected the behaviour of …

One comment

  1. This is an interesting article. One of the functions of a hierarchy is to have first access to the best food (like you said in the article), but also access to other important resources such as mates, water, shelter and perhaps other things that dogs find highly rewarding or important.

    Interestingly, there is also a link between anthropomorphich emotional involvement of the owner (for example, owners that feed their dogs specially prepared food and that want their dog to be loving and kind) and dog dominance agression. Possibly a combination of owner attitutes, diet, genetics and experiences could all contribute to dominance agression problems in dogs?

    For everyone interested in animal behaviour and emotions read my blog at

Leave a Reply

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

This site uses Akismet to reduce spam. Learn how your comment data is processed.