Why Is My Dog Throwing Up Undigested Food Hours After Eating?


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Your dog will throw up a few times during his lifetime, so you shouldn’t necessarily be worried every time your pooch vomits.

You should also understand that a dog who throws up isn’t necessarily ill or in need of urgent vet attention.

But what if your dog throws up undigested food? Should it be a concern? 

Well, we all expect every food that a dog eats to go down the esophagus and into the stomach for digestion. So, it can be distressing to see your dog throwing up undigested food immediately after eating or 8 hours (or more) after eating. 

But what can make your dog throw up undigested food in the first place? And what should you do about it?

Let’s find out.

1. The Dog Throws Up Immediately After Eating

If your dog brings up undigested food immediately after eating, there are high chances that you may be dealing with regurgitation rather than vomiting. So, it is important to understand the difference between the two before you take any action.  

When a dog is regurgitating, the process of bringing up the food tends to be more passive. In most cases, your dog will lower his head and cough out the food passively. The expelled food will be undigested considering that it never reached the stomach. Some dogs even re-eat the expelled food because it has not been soaked in stomach acids and may still be tasty.

On the other hand, when a dog is vomiting, he may drool and act apprehensively. The dog’s muscles will contract and his whole body will tense. You may also see the dog retching and see partially digested or undigested food along with a clear liquid (if the food is coming from the stomach) or green liquid (if the food is coming from the small intestine). You may also hear loud gurgling or whining noises from the dog’s stomach.

Pro Tip: Sometimes differentiating regurgitation from vomiting can be quite daunting. There are cases when your dog will vomit shortly after eating and there are instances when your dog will regurgitate several hours after eating or even a few days later.

If you are not sure whether your dog is vomiting or regurgitating, take a sample of whatever your dog has expelled out to your vet. Most experienced vets will tell you what it is by simply looking at the sample. When in doubt, the vet can run a quick pH test to differentiate between the two—pH for vomit containing food is acidic while pH for regurgitated materials tends to be higher.

Possible Causes

Regurgitation shortly after eating can be due to a wide range of causes, including

  • Eating too fast
  • Excitement
  • Stricture or inflammation of the esophagus
  • Tumors
  • Esophageal foreign bodies
  • Megaesophagus—a condition where your dog’s esophagus loses tone and dilates, making it less efficient in pushing food into the stomach.

2. The Dog Throws Up Food Hours After Eating

Why Is My Dog Throwing Up Undigested Food Hours After Eating

Vomiting partially digested or undigested food several hours after it was eaten indicates an abnormal delay in emptying of the stomach contents into the intestinal tract. Some of the most common causes of vomiting in dogs include:

  • Blockage: The dog may have ingested something that’s blocking the smooth passage of food. A dog with a blockage issue may vomit, experience abdominal pain, trouble defecating and even diarrhea. Common blockage culprits include table scraps, bones or garbage (stones, hair, sticks, rubber balls and other objects).
  • Diseases (stomach ulcers, cancer, diabetes, roundworms, or viral infections)
  • Ingesting poisonous substances such as antifreeze, household drugs, rat poison, pesticides, etc
  • Anxiety, stress or excitement
  • Ingesting fatty foods

Important FACTS to remember:

  • A healthy dog can vomit and go about the rest of his day normally—as if nothing happened. So, if the dog doesn’t show any other serious symptoms, he should be fine.
  • If the dog vomits several times in a day, there is blood in the vomit, or the vomit is accompanied by severe bloody diarrhea, pain, weakness, fever, depression, or lethargy, you need to see a vet because the dog might be suffering from inflammatory bowel disease, gastric ulcers, or other serious conditions. Your dog might also have swallowed a sharp foreign object. You should also be worried if the dog is refusing to eat or sleeping more than usual after vomiting.
  • Chronic vomiting can lead to serious dietary deficiencies if not attended to immediately. For instance, it may cause dehydration and electrolytic imbalances, which are often associated with tremors, muscle weaknesses, and other neurological problems.
  • If you suspect motility issues to be the cause of vomiting, consider giving the dog a light formula dog food. Canine nutritionists believe that high fiber dog foods boost motility by moving the food forward.

What to Do

Why Is My Dog Throwing Up Undigested Food Hours After Eating

Whether your dog throws food immediately after eating or a few hours later, there are a few measures that you can take, including:

  • Mild cases of regurgitation or vomiting can be solved by diet changes. Strive to keep your dog’s food choice as simple as possible. You should also ensure that your dog is well dehydrated. Other possible treatments for dehydration or other health issues resulting from the problem include IV fluids and antibiotics.
  • For recurrent vomiting, the most important thing is to identify and remove the root cause of the problem (your vet can assist you with this) and offering your dog appropriate fluids/electrolytes and relevant medications to soothe his stomach.
  • One of the best ways of preventing bowel obstruction is eliminating the initial problem—not letting your dog ingest foreign objects. So, be sure to watch your dog carefully (especially when it’s eating or playing in public areas) and keep potential hazards out of reach.

Related: 12 Easy Tips to Stop Your Dog from Stealing Food off the Counter

  • When your dog ingests a foreign object, there are instances where it is advisable to induce vomiting so that it doesn’t absorb toxins. However, there are cases when this is NOT advisable. For instance, NEVER attempt to induce vomiting if your dog ingests a sharp object, caustic materials (such as drain cleaners), or if he is unconscious. So, always consult your doctor before you induce vomiting in your dog. If your vet gives a green light, hydrogen peroxide is the most common solution to use.
  • If you establish that your dog is vomiting because he is eating too fast, consider investing in a slow or puzzle feeder. It will make your dog eat slower as it will have to work to reach the food. If you have more than one dog, you can also consider feeding them in separate rooms to avoid competition. Lastly, you can feed the dog several small meals a day.
  • Once your dog is treated and the vomiting stops, introduce him to low-fat foods in small quantities—3 to 6 times a day. Increase the amount of food and decrease the feeding frequency steadily as you transition to a normal diet. And if your vet had requested you to withhold water, consider re-introducing small amounts gradually.  

The Bottom Line

There are several causes of your dog vomiting or regurgitating food immediately or hours after eating. As highlighted above, know when vomiting or regurgitation is not normal and let your vet help you know the next course of action. Most importantly, always remember to clearly describe the type of vomit that you see in your dog and its behavior as it can make a whole lot of difference.

Finally, you need to keep in mind that if the cause of vomiting turns out to be an intestinal blockage, your vet will need to perform a meticulous examination and establish the location of the blockage using ultrasound or x-ray.  And your pooch may need to undergo surgery to remove the blockage.