Most dog owners will have seen their pets eating grass from time to time and, at some stage, the majority of those dog owners will ask their vet why their ‘carnivorous’ pet is indulging in this uncharacteristic behaviour!
While dogs’ digestive systems lack the enzymes required to effectively digest the cellulose in plant cell walls, that doesn’t mean they don’t eat plant material at all. In fact, dogs are actually omnivores, and can survive on a meat-free diet if the situation dictates.
One of the theories about why dogs eat grass is that it helps them manage nausea or helps them to vomit when they’re feeling unwell. A University of California study* of 1500 dog owners in 2008 found that 68% of owners said their dogs ingest plant matter on a daily or weekly basis and that while only eight percent of respondents said their dogs showed signs of illness before eating grass, 22% of owners reported their dogs vomited after eating grass.
That doesn’t, however, account for the proportion of dogs that don’t appear unwell before – or vomit after – eating grass.
While dogs have limited ability to digest intact plant material, they have evolved eating pre-digested plant and grain matter direct from the gut of their prey (and are equally capable of scavenging composting vegetable and fruit matter off the ground or compost heap where it has ripened and started to decay).
The fact that wild dogs choose to eat the gut content of their prey, filled with semi-digested plant and grain material, first is a clear and simple indication that the grain and vegetable content of the diet is vital to their health. Why else would they eat it first?
If you watch a dog eat grass for nutrition they are very selective, eating only the very fresh green shoots, not the bigger, greener blades of grass. That’s because the only fresh plant material dogs can digest is from very young shoots that have thin cell walls that can be more readily broken down than older plant cells with their indigestible, tough, lignified cell walls.
Dogs’ propensity to eat grass for nutrition reinforces the importance of a carbohydrate component to the canine diet. That’s why it’s vital to supplement your pet’s balanced fresh meat diet with a vegetable and grain component that mimics the way dogs would ingest plant material in the wild – in the gut of their prey.
For example, my Complete Mix includes crushed and cracked grains (that retain their nutritional value) and finely chopped or powdered vegetable matter in proportions that reflect the carbohydrate intake of a wild dog, soaked and fermented to replicate the gut content of prey animals, thus making it easily digested by pet dogs.
So don’t underestimate the importance of plant matter to the canine diet – unprocessed, cracked or crushed, pre-fermented, and even sometimes straight from the back lawn, plant matter plays its role in canine nutrition, albeit as a smaller portion of the diet than the vital fresh meat content.
*2008, Benjamin L Har, Drs Karen Sueda and Kelly Cliff, University of California.
Dr Bruce Syme BVSc (Hons) is a qualified veterinarian and the founder of Vets All Natural. He has developed this range of foods and supplements purely from his desire to heal more, and a wider range of animals than those seen in his clinic everyday.