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Home > Dogs > Why Is My Dog’s Poop Green? 4 Vet-Reviewed Reasons

Why Is My Dog’s Poop Green? 4 Vet-Reviewed Reasons

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Dr. Paola Cuevas

Veterinarian, MVZ

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When it comes to dogs’ bathroom habits, you might not pay much attention to the waste they’re leaving behind. After all, cleaning up after them tends to be a pretty mindless task. Every once in a while, though, your dog’s poop may look different enough from the norm to catch your attention. Like, if it’s green, for example.

Green poop definitely isn’t what our dogs should be pooping out, but occasionally it happens. The question then is, why is your dog’s poop green? There are a handful of reasons for this to occur, and, unfortunately, the majority will require a vet visit.

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The 4 Vet-Reviewed Reasons Your Dog’s Poop Is Green

Here are four possible reasons your dog’s poop is green and what you should do if you suspect one of them is causing your pet’s green poop.

1. He Ate Too Much of Something Green

The most common reason why a dog’s poop is green—and typically one that isn’t a concern—is because your pup ate too much of something green. Usually, this will mean they’ve been eating a ton of grass or plant material, as chlorophyll, in large enough amounts, can give poop a green color. Though eating grass isn’t harmful to your dog, it could be a sign that they are missing something nutritionally from their diet. If you think their diet is lacking, you can add more fiber to get their poop back to normal.

This could also be the result of overeating other things that are green such as crayons (don’t worry, crayons are non-toxic to dogs, though they could cause stomach upset in large quantities!) or even Greenies treats. Figure out what your pet is eating that’s green, so you can cut it out or reduce it.

shih tzu dog eating outdoors
Image Credit: thanakarn Singto, Shutterstock

2. He Has Ingested a Toxin Such as a Rodenticide

Another far scarier reason your dog’s poop could be green is that they’ve ingested a toxin—in particular, rodenticide. Rodenticide contains a green-tinted (and sometimes blue-tinted) pigment that is very dangerous for dogs to consume. While your dog may seem okay first, this is an emergency. The toxin will affect your dog’s health, causing their blood to lose the ability to clot. Once that happens, the smallest of cuts or bruises could lead to death. If you fear your pet might’ve gotten into rodenticide, it is vital to immediately get them to a vet.

3. He Has a Parasitic Infestation

Your dog’s poop could also be green because of a parasitic infestation. One type of parasite known to cause green poop is giardia. This parasite damages the intestinal wall by attaching itself to it, leading to chronic diarrhea, green poop, and weight loss. While not typically life-threatening, if you have a puppy or a dog with an immunocompromised system, they could have a rougher go of it. Giardia infections come about from a dog eating or drinking something that is contaminated with giardia cysts—such as grass or puddle water—and can be passed from dog to dog. Giardia can also be transmitted to humans. If you suspect a parasitic infection such as this, take your dog to the vet as soon as possible to get treatment.

sick australian shepherd dog
Image By: Irini Adler, Pixabay

4. He Is Suffering From an Intestinal Tract Medical Issue

Your dog might have green poop because he is suffering from intestinal tract issues such as gallbladder disease or colitis. Bile is a juice in the digestive tract that has a green tint, and when not reabsorbed as it should be, it can be passed along with poop. Other signs your dog’s poop may be because of gastrointestinal problems? It will not be the typical shape of their poop (instead, it will likely be runnier) and will often contain mucous. Again, this is a scenario where a vet should be contacted.



If your dog’s poop is green, whether you should be concerned or not could go either way. Chances are good that your dog simply ate too much grass or too many Greenies treats. Still, there’s also the possibility they could’ve ingested a toxin that needs immediate treatment or even have an infection or illness. Looking at the consistency and shape of your dog’s poop, along with the color, should help you determine the situation with which you’re dealing. If you’re unsure, though, your best bet is to consult your vet for guidance.

Featured Image Credit: SasaStock, Shutterstock

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