Grass eating is a common behavior in dogs, including Chihuahuas. In fact, a survey of 72 dog owners conducted in 2008 found that 79% of dogs ate grass. While this study is relatively small, it reveals just how common this behavior is among man's best friend.
From an owner's perspective, seeing your Chihuahua eat grass can raise some questions. Is my Chihuahua sick? Is grass eating harmful? Is it normal for Chihuahuas to vomit afterwards? Why exactly is my Chihuahua eating grass? How do I stop my Chihuahua from devouring my lawn? Should I schedule an appointment with the veterinarian? These are all reasonable questions to ask, and while this topic is highly debatable, we're going to try and answer them.
Is it Normal for Chihuahuas to Eat Grass?
With roughly 3 out of 4 Chihuahuas exhibiting this behavior during their lifetime, most experts agree that grass eating is normal. Some Chihuahuas are finicky and prefer specific varieties such as fescue or ryegrass, while others are less discriminate and willing to eat any grass they can get their paws on. Regardless, you've probably seen your pint-sized companion eat grass at least once. It's a normal behavior exhibited by all dogs, both big and small.
Understanding why Chihuahuas eat grass, however, is more difficult. We've learned a great deal about man's best friend since we first domesticated them some 15,000 years ago, but we've yet to draw a conclusive answer to this question.
Theory #1) Digestion
One of the most popular theories is that dogs, including Chihuahuas, eat grass to improve digestion. When a Chihuahua has an unset stomach, intestinal blockage, gas, or other digestive issues, they may seek grass to induce vomiting and offer relief -- at least that's what some experts believe. Upon ingestion, the indigestible plant matter tickles the throat and stomach, causing them to vomit. This is particularly true when the Chihuahua swallows grass whole without chewing it (you can see whole blades of grass in the vomit).
But not everyone is on board with this theory. Researchers from the University of California, Davis conducted an online survey of 1,571 dog owners, in which they discovered that only 22% of dogs regularly vomited after eat grass, and only 8% of dogs had exhibited signs of illness prior to eating grass. If Chihuahuas ate grass to induce vomiting and improve digestion, these numbers would likely be higher. Granted, that's only a single study, with a limited data pool nonetheless, but most canine experts reject the theory that dogs eat grass for this reason.
Theory #2) Nutritional Deficiency
Another theory is that Chihuahuas eat grass is because they suffer from a nutritional deficiency. If your Chihuahua isn't getting the necessary nutrients through their regular diet, perhaps they'll look for alternative sources, such as your lawn. Grass doesn't offer the same delicious flavor as premium chicken/beef/lamb dog food, but it still contains key nutrients such as fiber, vitamin A, vitamin C, vitamin E, vitamin B6, iron, zinc, niacin, thiamine, riboflavin and selenium.
The problem with this theory is that eating grass offers little-to-no nutritional value for Chihuahuas. Grass consists mostly of cellulose, which passes right through dogs' digestive tract without the nutrients ever being absorbed. Chihuahuas benefit from the fiber, which softens stools and eases bowel movements, but they won't benefit from the vitamins or other nutrients in grass. Cows, deer, goats and other grazing animals have multi-chambered stomachs with microorganisms known as archaebacteria, allowing them to digest grass. Us humans and our canine counterparts, on the other hand, have single-chambered stomachs, preventing such digestion.
Theory #3) Intestinal Parasites
A third theory is that Chihuahuas eat grass to purge intestinal parasites, such as roundworms, whipworms, hookworms and tapeworms, from their bodies. The high fiber content of grass could flush out such parasites. According to Kansas State University's Veterinary Health Center, approximately 34% of all dogs in the United States are infected with gastrointestinal parasites. In the southeastern states, this number jumps to 54%. If a Chihuahua suffers from an intestinal parasite, perhaps they'll eat grass to vomit and purge the parasite from their digestive system.
But if your Chihuahua is on a worm preventative medicine -- like they should be -- there's no reason for them to purge intestinal parasites by eating grass, right? Some experts believe dogs inherited this trait from their wolf ancestors, who may have eaten grass to purge intestinal parasites. Wolves also preyed on grass-eating animals like squirrels, foxes, gophers and deer, eating their entire grass-filled stomachs. So even if your Chihuahua is parasite-free, they may continue to exhibit this behavior because it's hard-wired in their DNA. An article published in the Journal of Veterinary suggests that feral wolf mothers who eat grass during pregnancy are more likely to give birth to grass-eating puppies.
Theory #4) Boredom
Maybe your Chihuahua eats grass simply because they are bored. Chihuahuas need regular mental and physical stimulation. If they don't receive this stimulation, they'll become bored and seek other ways to pass the time. This may include chewing on carpet, tearing up rolls of toilet paper, barking, biting their nails, and eating things they normally wouldn't, such as grass.
This problem is easily avoided by providing your Chihuahua regularly exercise, preferably at least 30 minutes per day, and leaving plenty of toys around. Puzzle toys are particularly useful for keeping dogs occupied. They typically feature a hidden compartment in which a treat is placed. In order to retrieve this treat, your Chihuahua must knock the toy around until it falls out. The only downside with puzzle toys is that most dogs learn how they work after a couple of times, allowing them to retrieve the treat with little effort.
Potential Dangers and Problems Associated with Eating Grass
The risk of any major health problems developing in Chihuahuas from grass eating is generally low. Grass is a safe, all-natural substance, albeit indigestible with virtually no nutritional value for dogs -- but it could be harboring other things which are harmful to Chihuahuas. Furthermore, consuming too much of any substance isn't good, and grass is no exception.
Here are some of the dangers associated with Chihuahuas eating grass:
- Pesticides. Many homeowners and municipalities treat lawns with pesticides, which a Chihuahua may inadvertently consume when eating grass. In fact, we use more than one billion pounds of the stuff each year -- and that's only here in the U.S. Pesticides often contain toxic chemicals such as ammonia, arsenic, benzene, chlorine, dioxins, formaldehyde and methanol, which can cause serious illness or death when consumed by a Chihuahua. A study published in the January 2012 issue of the Journal Environmental Research found that exposure to lawns professionally treated with pesticide was linked to 70% higher risk of canine malignant lymphoma (CML). This study focuses specifically on professional-grade pesticide, but even consumer-grade pesticides are toxic to dogs.
- Fertilizers. Even if the grass is pesticide-free, it may contain fertilizer that's toxic to dogs. According to the Pet Poison Helpline, ingestion of fertilizer was one of the top 10 most frequently reported poisonings in dogs in 2011. Most grass/plant fertilizers contain three primary ingredients: nitrogen, phosphorus and potassium. However, some contain other ingredients like copper, zinc, boron and molybdenum. Due to their small size, Chihuahuas are particularly susceptible to poisoning from lawn fertilizers and pesticides.
- Other toxic chemicals. There's also the possibility of other toxic chemicals like antifreeze leaching onto the grass. The main ingredient in many automotive antifreeze products, ethylene glycol, is highly toxic to dogs, with a lethal dose being just 2-3 ml/lb. If your Chihuahua weighs five pounds, consuming as little as 10-15 ml can be fatal. In 2012, manufacturers added a bittering agent to make their antifreeze products less appealing to pets and animals. Earlier generations of antifreeze had a sweet taste and odor, attracting animals to the toxic chemical. But even with the recently added bittering agent, antifreeze remains a leading cause of pet poisoning. The Humane Society recommends choosing antifreeze with propylene glycol instead of ethylene glycol, which is still toxic but safer than its counterpart.
- Toxic plants. Your Chihuahua isn't going to get sick from eating grass alone, as none of North America's common grass species are toxic to dogs. If your Chihuahua consumes a plant, though, it could be a different story. There are hundreds of native plants that can make your Chihuahua sick when ingested, some of which include azaleas, cyclamen, lilies, oleander, daffodils, lily of the valley, and tulips. According to a poll of 2,00o cat and dog owners conducted by the insurance firm More Than, 1 in 12 pets has eaten a toxic plant.
- Dangerous grass. Just because grass isn't toxic doesn't mean it's safe for your Chihuahua to eat. Foxtail grasses (Alopecurus, Bromus madritensis, Hordeum jubatum, and Setaria) contain barbed seed awns that are razor-sharp. After entering the body, foxtail awns can pierce holes in tissue and organs, causing serious injury or death. If you live near foxtail grass, keep your Chihuahua away at all times. Dogs can injure themselves simply by walking on or near foxtail awns, without ever ingesting them.
- Parasites. While some experts theorize that dogs eat grass to purge parasites from their system, this behavior could actually expose our canine companions to new parasites. Roundworms and hookworms are transmitted through the feces of an infected host, so if your Chihuahua eats grass containing feces -- not pleasant but it happens -- they too could become infected. The risk of infection is low, especially if your yard is inaccessible to other dogs, but it's still something owners should be aware of if the Chihuahua isn't on a worm preventative medicine like Trifexis.
- Intestinal blockage. Another problem with grass eating is the potential for an intestinal blockage. As previously mentioned, Chihuahuas cannot digest grass, so it simply passes through their digestive system without ever being broken down. If a Chihuahua eats too much grass, though, it may accumulate inside their intestines, preventing food from passing through. Intestinal blockages such as this can be fatal if left untreated. The obstruction prevents blood from reaching the gastrointestinal tract, resulting in necrosis of tissue and perforation.
- Tooth decay. When you think of hazards associated with grass eating, tooth decay probably isn't at the top of your list. However, grass contains high concentrations of silica (silicon dioxide) that can wear down the enamel of your Chihuahua's teeth, causing decay and subsequent oral problems.
When to See a Veterinarian
You don't have to rush your Chihuahua to the local veterinarian just because they ate a mouthful of grass. As long as they didn't consume any toxic chemicals or plants in the process, it should pass through their digestive system, regardless of whether they vomit afterwards. If your Chihuahua vomits before eating grass, though, it could be a sign of an underlying illness, in which case you should schedule an appointment to see the veterinarian ASAP.
Other symptoms that should prompt a visit to the veterinarian include lethargy, diarrhea, tremors, seizures and constipation.
*If you believe your Chihuahua has eaten grass with pesticides, fertilizers or other toxic chemicals, contact the Animal Poison Control hotline at (888) 426-4435. They have veterinary experts standing by, 24 hours a day, 365 days a year, to provide assistance with pet poisonings.
How to Stop Your Chihuahua from Eating Grass
While common behavior among dogs, many owners prefer their Chihuahuas to not eat grass. It increases the risk of toxicosis, parasites, intestinal blockages, and it can lead to tooth decay. So, how do you stop your canine companion from feasting on your lawn?
Use a Leash!
Start by walking your Chihuahua on a leash instead of allowing them to roam free. Most Chihuahuas know they shouldn't be eating grass, so they'll sneak out of their owner's sight to engage in this behavior. But if you walk your Chihuahua on a leash, you can supervise them the entire time. Besides, allowing your Chihuahua to go outside without supervision places them at risk for serious injury from snakes, hawks, foxes and other predators.
And if your Chihuahua is wearing a harness instead of a collar, gently pull back on the leash when you see them eating grass. Harnesses distribute the force of pulling safely across their torso, whereas collars place the force directly around their neck. You should only pull back on the leash if your Chihuahua is wearing a harness, not a collar.
Divert Your Chihuahua's Attention
If you see your Chihuahua trying to eat grass, divert their attention towards something else, such as another part of the yard. Chihuahuas love exploring the outdoors, and many prefer walking alongside their owner instead of munching on grass in solitude. Using a recall command like "come here boy/girl" should catch their attention, stopping this behavior in its tracks. Sit and heel are also commands that can stop your Chihuahua from eating grass.
You can also divert your Chihuahua's attention away from grass eating with toys. Chihuahuas are typically too small to retrieve frisbees, but tennis balls are perfect for these pint-sized companions. Toss a tennis ball across the yard while telling your Chihuahua to "go get it! Chihuahuas possess an instinctual drive to chase varmints and small moving objects. so when they see a tennis ball bouncing in the opposite direction, they'll dart towards it.
Positive Reinforcement, Not Punishment
Don't scold or otherwise punish your Chihuahua for eating grass. Punishing them for an instinctual behavior they likely inherited from their ancestors is ineffective and counterproductive. Your Chihuahua may act out in response to being punished, or they may eat grass the next time they want your attention. To stop your Chihuahua from eating grass, focus on attention diversion and positive reinforcement through basic obedience commands.
And if you allow your Chihuahua to eat grass, make sure it's not treated with any pesticides, fertilizers or other chemicals. Some canine experts even recommend the creation of a special grass or herb garden that's designed specifically for dogs to eat.
We may never know why Chihuahuas eat grass. Theories such as digestive problems, nutrient deficiency, intestinal parasites and boredom are all possible, but there's no definitive answer. Grass eating is a common behavior exhibited by most dogs, and it rarely causes any need for concern. Just keep a close eye on your Chihuahua to see if they exhibit symptoms of an underlying illness.
Is your Chihuahua a grass eater? Let us know in the comments section below!