What Causes a Dog to Eat Grass & Vomit Daily?

As many pet owners know, some dogs like to eat grass. This fact is backed up by Pet Place and Pet Library, both of which offer various reasons behind a dog's grass-eating habit--and the vomiting that often follows. Both say a dog's grass-eating tendencies are normal. It should only be a concern if a dog also exhibits symptoms of a larger problem, like pica.

  1. Hunting History

    • Dogs are relatives of foxes and wolves, carnivores that captured prey that happened to be herbivores, according to Pet Place. As with many animals that hunt, the hunters often first fed on their prey's stomach and what was inside it. The taste for grass developed after finding--and enjoying--the greens in the herbivores' stomachs.

    Scavenging History

    • When hunters cannot catch live prey, they learn to scavenge for food, according to Pet Library. That food includes anything that looks good, often consisting of leaves, roots and plants. Scavengers are not picky about what they eat. Dogs are equally as open-minded about the food they consume, often not particular at all and find grass as good as anything else around the yard.

    Lacking Greens

    • Another theory, according to Pet Place, is that dogs eat grass because they are lacking vegetable matter in their diet. Dogs go for the grass to supplement their diet and fulfill their need for greens. Pet Library notes dogs will often do this even when their particular food is nutritionally complete as they need the fiber grass has or may simply like the taste.

    Pica

    • Dogs may also eat grass because they suffer from pica, veterinarian Bari Spielman writes in a Pet Place article. Pica is a condition where dogs crave and eat items normally not considered food, like rocks, feces and even grass. Discern between normal grass eating and pica by looking for pica symptoms like diarrhea, abdominal pain, collapsing and chronic bad breath. Vets can treat pica, Spielman said.

    Vomit

    • Dogs that eat grass often vomit, according to Pet Place and Pet Library. Pet Place explains grass irritates the dog's digestive system, inducing him to vomit. Pet Library adds dogs that eat grass quickly are more likely to vomit than pooches who eat grass slowly and methodically as large quantities of larger grass pieces are more irritating than smaller pieces in smaller doses.