Dog owners have often notice that their dog will eat grass and other plants that have no real nutritional value. Research shows that wild canids and felids eat grass and plants—plant material as well. Fresh grass doesn’t provide nutrients which raises the question of whether there is an underlying biological reason for this behavior.
So, why do animals eat grass? Often owners wonder if it is to induce vomiting because they’re sick. Or if dogs eat grass because they have a dietary deficiency.
A survey of veterinary students who had pet dogs (n=25) were asked about the frequency of grass eating in their own dogs and whether the students observed signs of sickness before grass consumption or vomiting afterward. All of the students reported that their dogs ate grass and none of them said that their dogs were ill before eating the grass. However, 8% said that their dogs vomit afterward.
One survey of dog owners found that 79% had observed their dogs eating plants (grass was the plant most frequently consumed). They also reported that rarely did their dogs show signs of illness and vomiting occasionally after their dogs eating grass.
The UC Davis School of Veterinary Medicine performed a survey in 2007 regarding grass ingestion among dogs and any correlation between eating grass and illness. This study found that although dogs frequently eat grass, there is no relationship with illness. However, some dogs did vomit after eating grass. The study also found dogs without regular access to grass were more likely to vomit after ingesting it.
It is possible some dogs may learn to associate grass-eating with vomiting and will, therefore, eat it when feeling ill. However, this study revealed that grass ingestion does not appear to be a form of self-medication in dogs with clinical illness.
A University of New England in Australia study in 2007 found that dogs eating grass did it because of hunger. The study found that dogs were more likely to eat grass before a meal and less likely to eat grass when they were full. The study revealed that grass was used by the dog to feel full.
So what does all of this mean and why do dogs eat grass? First, it is normal and common behavior among dogs. Dogs appear to eat grass instinctually and closely related to the ingestion of partially digested plants by wild canids. Eating grass is not associated with clinical disease even though some dogs may vomit after doing so. Excessive grass ingestion may simply be due to hunger. In such cases, this behavior may be reduced by increasing the frequency of meals or providing an appropriate amount of fiber supplementation in order to increase satiety. Any dog that appears ill before or after ingesting grass should be evaluated for underlying
medical conditions such as gastrointestinal disease, intestinal parasite infestations, and plant or