Why does my dog eat grass?

One of the most common questions we get here at Van Isle Veterinary Hospital is “Why does my dog keep eating grass?” Unfortunately, we’re sorry to say there is no real answer to this age-old question even though there have been 100’s of studies done over the years from US Davis down to top animal behaviourists.

There are several theories, one of which goes back to ancestral days with a wild dog’s needs to fulfil its dietary requirements.

What People Commonly Think:

1. They don’t feel well and are trying to make themselves vomit. However, about 75% of normal, healthy dogs eat grass and plants without ever vomiting or regurgitating and less than 10% of dogs will vomit/regurgitate shortly after eating grass. Many believe a dog will graze on grass to alleviate an upset or gassy stomach. If eating grass is a new behaviour for your dog or the occasional graze turns into aggressive, all out gulping of grass and plant material, this could be a sign of an underlining illness and should be brought to your veterinarian’s attention.
2. They have internal parasites that they are trying to rid themselves of. There are wolf studies that think the grass and plant material helps to lower parasite loads or aid in digestion by providing fiber and nutrients but statistics still show that 70% of domesticated dogs with balanced diets and good parasite control still eat grass. Perhaps this is just simply a passed down trait from their less domesticated ancestors.
3. They eat grass simply because they are bored. Some dogs will develop behavioural eating patterns such as Pica which is the term used for eating things other than food. This is often noted in young puppies and some think it can either be related to boredom as well as a nutritional deficiency in the diet. If you suspect boredom, you can start by increasing your dog’s amount of daily exercise or introducing a new toy or activity into their routine. If you are concerned about their dietary needs or suspect a nutritional disorder, consult with your family veterinarian for advice on a balanced, daily diet.

Although nobody really seems to know exactly why dogs eat grass, most experts will agree that the occasional grazing itself in not harmful to your pet and it seems to be quite normal. However, grazing in unknown areas which could contain fertilizers or pesticides is another story and could be quite harmful to your pet. If your dog is a grazer, you may want to monitor him or keep him on a leash in unfamiliar environments. A new study even suggests dogs eat grass simply because they like it!

Written by: Van Isle Veterinary Hospital