Can dogs eat grass?Grassy parks and fields are popular places for a dog to stroll around, do their potty breaks, take leisurely walks, and even play with their owners. Having a backyard at home also means having an accessible small grass field where your dog can easily do their business or play a short game of fetch. But you may have noticed that your dog likes to eat the grass too. Many speculations have been made as to why dogs do this, from a nutritional point of view to the psychological interpretation of this unusual behavior. What does it really mean when dogs start eating grass and does this have any effect on the dog’s overall health?FirstVet is the #1 online video veterinary service.FirstVet offers video calls with experienced veterinarians for just $35. You can get a consultation within minutes by downloading the FirstVet app for free from the Apple App Store or Google Play Store. Over 500,000 users trust FirstVet to care for their animals. Rating: 4.9 - more than 1600 reviewsRating: 4.9 - more than 1300 reviewsRating: 4.9 - more than 1600 reviews Download app The Old Belief That Illness is Behind the Grass-Eating Behavior in DogsInitially, it was thought that when dogs eat grass, it means that the dog is not feeling well and may need medical attention. This belief stems from the observation in the livestock industry when farm cows or horses tend to chew on unusual things when there is some degree of nutritional deficiency happening. Most cattle lots have salt licks in them that cows can chew or lick as means to satisfy the animal’s nutritional needs, particularly minerals like sodium.This practice in livestock farming has led dog owners to believe that when dogs start eating unusual things, particularly grass, it means that the dog has some sort of illness or deficiency that must be addressed. However, recent studies have shown that less than 10% of dogs that have exhibited grass-eating behavior were unwell prior to chewing on grass. This refutes the age-old misconception that dogs are attempting to self-medicate an illness when they eat grass.So, why do they eat grass?Is grass-eating a physical need for dogs?Like humans, dogs need a well-balanced diet to sustain their health. Domestic dogs, unlike their wolf ancestors, have a more diverse nutritional requirement and need more than just protein to survive. An important nutrient that dogs need, among vitamins and minerals, is fiber. Fiber helps improve digestion and control the transit of food through the GI tract.It’s believed that when dogs eat grass, they’re trying to graze roughage to fulfill their fiber needs. A lack of fiber in a dog’s diet can lead to constipation, sometimes diarrhea, and indigestion. Occasionally eating grass helps meet their dietary fiber needs and prevents GI problems that come with the lack of it.Of course, if the dog gets a high-quality, well-balanced meal every day, then theoretically they wouldn’t need roughage. But some dogs still eat grass when outside despite being on a highly nutritious diet. Which opens the possibility of non-physical reasons for the grass-eating behavior in dogs.A Psychological Perspective on the Grass-Eating Behavior of DogsDogs’ psychological behavior has been studied thoroughly over the past decade, and there have been several theories that were developed to explain why dogs like eating grass.Though most dogs can maintain their focus on a single task if commanded to, these same dogs also show a relatively short attention span when in leisure or during play. Dogs enjoy playing outside but tend to get bored easily, especially when left alone. This boredom drives them to nibble on the grass to pass the time. This behavior is essentially a very accessible and easy way for dogs to kill boredom and fill hours.They also nibble on grass when they’re stressed or anxious, studies have shown. Dogs in general like attention from their owners, other people, and sometimes other dogs. When left alone, they feel anxious and stressed. Dogs that experience anxiety tends to nibble on grass much like an anxious person bites on their fingernails. It has been observed that the length of time a dog spends chewing and eating grass increases as the contact time with its owner decreases.Another growing theory about this odd behavior is that there’s no actual physical or psychological reason why dogs eat grass aside from the fact that they just like it. They like the texture and the taste of the grass when chewed.Does eating grass affect your dog’s health?Contrary to the traditional belief that dogs eat grass because they’re unwell, many dog owners now think that the behavior can lead to various health problems. While this may be true to some extent, studies have shown that less than 25% of dogs that eat grass show signs of illness afterward. Of course, there are still risks associated with grass-eating which cannot be overlooked.Though most dogs don’t show any adverse reaction towards grass, there are reported cases of acute gastritis and diarrhea in dogs after they’ve eaten a substantial amount. Grass can trigger an inflammatory reaction along the lining of the stomach and intestine which can lead to gastrointestinal problems like profuse vomiting or diarrhea.Grass-eating behavior can also cause gastrointestinal obstruction in dogs. Since grass is high in fiber, eating a lot of it can cause a delay in the movement of the intestinal tract and may lead to constipation or worse, intestinal blockage, which requires surgical intervention to treat.Frequent grass-eating also makes dogs prone to intestinal parasites. Grass can be a source of intestinal parasites like worms or coccidia which, when ingested, can cause signs ranging from simple diarrhea to neurological problems. Dogs that are not on regular parasite preventive medications are highly susceptible to the contraction of various parasites from eating grass.Lastly, grass-eating can cause toxicity in dogs due to herbicide and insecticide ingestion. Most grass parks are regularly treated with herbicide and insecticide as part of their maintenance, and sometimes the active component lingers longer than intended. Some plants are found in grass fields that are inherently toxic to dogs. When dogs eat grass that was recently treated or has remnants of the chemicals or if they eat a toxic plant in a grassy field, it can lead to toxicity signs which may require intensive care to treat.When should I stop my dog from eating grass?The next time you decide to bring your dog outside for a walk in a grassy park, make sure to keep an eye on her all the time and take the necessary action as soon as you see her attempt to nibble on grass. Always be aware of any recent herbicide or insecticide treatment in your local dog park. Lastly, contact your vet immediately if you suspect that your dog may have eaten a toxic plant, contaminated, or recently treated grass.Read more:What plants are toxic to dogs?What foods are toxic to dogs?Mushroom Poisoning in DogsNeed to speak with a veterinarian regarding your dog's eating habits or another condition?Click here to schedule a video consult to speak to one of our vets. 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