Why Do Dogs Eat Grass?
There are many theories about why dogs eat grass, some people think dogs do it to induce vomiting, for roughage (laxative purposes), whilst others believe some dogs just like the taste or texture.
A group of scientists from the School of Psychology at the University of New England in Armidale NSW decided to test out a few of the theories of grass eating in “Canis familiaris” – otherwise known as the dog!
The study attempted to “describe the pattern of the dog eating grass during the day and the relationship between grass eating and the ingestion of food”.
The controlled experiment relied on studying twelve dogs. Essentially, they were offered a meal of Kikuyu and Couch grass three times daily for six days.
It should be noted the dog group were also fed kibble, which is mostly composed of grains and vegetable matter with a minority share of meat. Dogs fed on a raw meat diet may indeed have a different purpose for eating grass.
FINDING #1 Dogs Consider Grass a Food Source
The study concluded that dogs may consider grass mostly as a food source.
They concluded this because the subjects were less likely to eat grass when they were full of food – see Figure 1 and Figure 2 below.
Previous research I have performed has also shown that many forms of grass contain a significant amount of Omega 3 (an essential fatty acid, essential to the health of dogs). While grass like flax contains the vegetable form of Omega 3 that is not as easily digested as the fish form of Omega 3, but it is better than nothing.
And while some forms of kibble include Omega 3, when it is exposed to light and oxygen (i.e., the first time you open a dog food packet), within a few hours the Omega 3 can degrade and lose some of its nutrition value. In my opinion this is why it may be necessary for dogs to seek out Omega 3 from a live food source such as grass.
It is also noted many dogs eat grass from dog parks, that will have a different vitamin and mineral composition from grass in other parks or at their owner’s homes. And that grass is a living ‘whole raw food’ as opposed to a man made a manufactured composition that only has what the manufacturer chooses to add to the mix.
FINDING #2 Time Spent Eating Grass Decreased Throughout the Day
The study also concluded that dogs spend less time eating grass as the day progresses.
They concluded this because there was a decrease in both time spent and the number of events of grass eating from the morning, noon, and evening sessions – see Figure 3 and Figure 4 below.
Some Other Interesting Points:
As a dog walker, I have also noticed a massive increase in dogs in general eating grass around springtime. It may be the taste or the tactile value of the new shoots, but it could also be an increased level of some nutritional component in the grass at this time.
While it is anecdotally known that many dogs eat grass to purge themselves of something that is causing them indigestion problems, this study found no specific instance of dogs eating grass to be sick.
The University of New England study also shows that dogs are willing to eat both Couch and Kikuyu grasses almost equally.
You probably won’t be surprised that a preliminary pilot study showed that dogs ate only up to a few grams of grass per ‘meal’ and preferred to eat grass presented from a plant rather than cut and presented.
A study by Sueda (2005) also showed that dog grass eating behaviour showed “no relationship between plant eating and gender, gonadal status (whether the dog has been neutered or not), breed, diet, or presence of intestinal parasites.”
Should you be worried if your dog eats grass?
Unless a dog is eating grass to invoke vomiting, it is mostly seen as a nutrient source to add to its main meal. The University of New England study also shows how common grass eating is in dogs and that it is a natural activity inherited from the domestic dog’s evolution from the grey wolf. Unless a dog is eating grass and vomiting after each episode, grass eating in your dog is not cause for excessive worry.
That being said, my gut instinct is that a well-fed dog who eats grass could be seeking either Omega 3 or another nutrient that is missing from their current diet. On this basis you could try adding in some alternative food or treat to their day.
Perhaps try some of our Omega 3 rich treats including Flake Fillets, Hoki Jerky, Salmon Skins or any of the Kangaroo range. These suggestions are also a departure from beef and chicken, which are the most common meat choices for many owners.
Article by Bruce Dwyer. If you wish to use any of this information, please refer to the article as a reference and provide a link to our WEBSITE.
Reference
Grass eating patterns in the domestic dog, Canis familiaris (published 2007)
S.J. Bjone1,2, W.Y. Brown3 and I.R. Price1
University of New England, School of Psychology, Armidale, New South Wales, 2351