Seeing your dog vomit yellow foamy liquid is alarming, especially when the vomiting is sudden, repeated, or accompanied by clear discomfort.
That yellow foam—often called bile vomit—usually comes from the stomach or small intestine.
We outline the common causes of a dog vomiting yellow foamy liquid, what you can do at home, and when to seek veterinary help.
Dog Vomiting Yellow Foamy Liquid — Why It Happens
A dog vomiting yellow foamy liquid may be experiencing bile irritation, an empty stomach, gastritis, acid reflux, dietary indiscretion, pancreatitis, infections, or more serious digestive issues. While bile vomiting can sometimes be mild, repeated episodes always deserve close attention.
Dog Vomiting Yellow Foamy Liquid: Common Causes
Bilious Vomiting Syndrome
One of the most common reasons dogs vomit yellow foamy liquid is because their stomach is empty.
Overnight or long gaps between meals allow bile from the small intestine to backflow into the stomach. This bile is irritating and triggers vomiting when the stomach has nothing else to expel, producing a yellow, foamy mixture.
Dogs with bilious vomiting syndrome often vomit early in the morning or late at night, especially if they ate dinner too early or skipped a meal.
They may appear nauseated before vomiting—licking their lips, swallowing hard, eating grass, or pacing. Once they vomit the yellow foam, they often act normal again unless the stomach becomes irritated repeatedly.
Chronic or frequent bile vomiting can inflame the stomach lining and lead to ongoing digestive discomfort.
Read more: Dog Suddenly Not Eating and Vomiting (Why it happens)
Gastritis
Gastritis occurs when the stomach lining becomes irritated or inflamed. This irritation can be triggered by eating something unusual, spoiled food, fatty leftovers, human food, grass, plants, or even rapid diet changes.
When the stomach is inflamed, bile mixes more readily with stomach acid, causing the vomit to appear yellow and foamy.
Dogs with gastritis may vomit repeatedly, show signs of nausea, or refuse food temporarily.
The yellow foam often appears during the later stages of vomiting when the stomach is already emptied of food. Gastritis can worsen if the dog continues to vomit, as each episode increases stomach acidity and irritation.
Read more: Dog Vomiting White Foam and Yellow Bile (Why it happens)
Acid Reflux or GERD
Acid reflux happens when stomach acid and bile flow backward into the esophagus, irritating the sensitive tissues.
This backward flow leads to nausea, lip-licking, throat discomfort, and vomiting yellow, frothy bile. Dogs with reflux may vomit after waking, after exercise, or after long fasting periods.
Reflux can be triggered by fatty meals, spicy foods, eating too quickly, or underlying digestive disorders.
The yellow foam comes from bile mixing with swallowed saliva as the dog tries to soothe the discomfort. Some dogs also cough, clear their throat, or swallow repeatedly because the acid irritates the upper airway.
Dietary Indiscretion
Dogs who eat trash, table scraps, bones, spoiled food, or outdoor debris often develop acute vomiting. When the stomach is irritated by an offending material, it expels the contents quickly.
Once the food has been cleared, the dog may continue vomiting bile, resulting in the yellow foam owners commonly see.
Dietary indiscretion can also trigger diarrhea, gas, abdominal discomfort, or bloating. Vomit may start as food but become yellow and foamy as the episode continues.
If the dog consumed something toxic or indigestible, vomiting may worsen and become more dangerous.
Pancreatitis
Pancreatitis—inflammation of the pancreas—is a serious condition that often begins with vomiting yellow bile. The pancreas releases digestive enzymes that can irritate surrounding tissues when inflamed, causing intense abdominal pain, nausea, and repeated vomiting.
Dogs with pancreatitis often vomit bile because their stomach becomes empty quickly from repeated vomiting.
The yellow foamy liquid may appear early, but the vomiting often becomes more frequent and severe. Other signs include lethargy, hunched posture, restlessness, and refusal to eat.
Fatty foods, obesity, metabolic disease, and certain medications increase the risk of pancreatitis.
Intestinal Blockage
When something blocks the digestive tract—such as a toy, bone, sock, or rawhide—the stomach becomes unable to push food forward.
As pressure builds, dogs vomit repeatedly. Once the stomach empties, they begin vomiting bile, which appears yellow and foamy.
Obstruction is extremely dangerous and can progress rapidly. Dogs may drool excessively, pace, strain to defecate, or show abdominal swelling. Vomiting yellow foam is often an early warning sign that the stomach is empty but still attempting to expel contents.
As obstruction worsens, vomiting becomes more forceful, and dehydration sets in.
Parasitic or Infectious Illness
Certain parasites (like roundworms, hookworms, or Giardia) and infections (like parvovirus) can cause vomiting yellow foam due to inflammation, nausea, and digestive disruption.
When the stomach cannot hold food, bile becomes the primary material expelled.
Dogs with infections or parasites may have diarrhea, weight loss, reduced appetite, or lethargy along with vomiting. Puppies are especially at risk, and vomiting bile can be an early sign that the illness is progressing.
Liver or Gallbladder Issues
The liver and gallbladder play essential roles in bile production and digestion. When these organs are inflamed or impaired, bile can overflow or move irregularly, causing vomiting.
Yellow, foamy vomit may appear alongside lethargy, jaundice, pale stool, or reduced appetite.
Liver disease changes how bile is produced and moved, leading to digestive upset and increased nausea. Dogs may vomit more frequently in the morning or after eating fatty foods.
Read more: Dog Coughing Up White Foamy Mucus (Causes explained)
What to Do If Your Dog Is Vomiting Yellow Foamy Liquid
Begin by giving your dog a calm environment and allowing their stomach to settle. Offer small sips of water once the vomiting pauses, but avoid large amounts that might trigger more vomiting. Hold off feeding for several hours to give the stomach time to rest.
After a brief fasting period, introduce bland, easily digestible food—such as boiled chicken and rice—if your dog is willing to eat. Feeding smaller, more frequent meals may help prevent bile from accumulating in the stomach, especially if the vomiting tends to occur in the morning.
Avoid giving treats, fatty foods, or table scraps. Keep your dog from grazing outside, eating plants, or accessing trash. Monitor closely for lip licking, swallowing hard, pacing, or restlessness—signs that nausea may be returning.
If your dog vomits yellow foam once and then seems normal, the cause may be mild stomach irritation. However, repeated episodes, especially if paired with lethargy or refusal to eat, require veterinary care.
When to Call or Visit Your Vet
Contact your veterinarian if your dog:
• Vomits yellow foam more than once in 24 hours.
• Vomits repeatedly or cannot keep water down.
• Shows lethargy, shaking, or weakness.
• Has diarrhea along with vomiting.
• Displays abdominal pain or a hunched posture.
• Has a swollen or firm abdomen.
• Vomits after eating something suspicious.
• Has blood in the vomit or stool.
• Has pale gums or signs of dehydration.
• Is a puppy, senior dog, or has chronic health conditions.
• Shows ongoing vomiting in the morning.
Repeated bile vomiting may signal deeper digestive or metabolic issues that require prompt treatment.
Read more: Dog Throwing Up Yellow and Not Eating (Here’s why)
Key Takeaway
A dog vomiting yellow foamy liquid is expelling bile due to irritation, an empty stomach, inflammation, reflux, pancreatitis, dietary indiscretion, or more serious digestive problems.
While a single episode isn’t always urgent, repeated bile vomiting must be taken seriously.
With early care, a monitored diet, and veterinary evaluation when needed, most dogs recover fully and return to comfortable digestion.