White Foam Vomiting in Dogs

There are several reasons a dog might vomit whitish or yellowish foam, a sign that something isn't functioning normally in the upper part of the digestive tract (usually the stomach and duodenum).

Some of the causes behind this vomiting aren't very serious once properly diagnosed by a vet. However, there are also more serious causes, sometimes even very urgent ones. Let's go step by step through the causes that can make a dog vomit and how to identify them.

My dog is vomiting foam — what's the reason?

Whitish, foamy vomit can usually be classified as a normal type of vomiting. When there's no content (food) in the upper part of the small intestine or stomach, what comes up is the saliva that's naturally present. The yellowish, mucous part sometimes seen is bile residue.

Vomiting is a gastrointestinal symptom, which may or may not be accompanied by trembling and/or diarrhea. Usually (not always) this type of vomiting points to irritation in our dog's small intestine or stomach. Veterinary attention will be needed given how many possible causes there are.

Below, after the point on the difference from regurgitation, we describe the causes from most to least common, based on veterinary emergency experience.

Vomiting vs. regurgitation

The main differences between vomiting and regurgitation are:

• Vomiting: preceded by retching. It can happen anywhere from 5 minutes to several hours after whatever's causing it, so it won't happen right after eating. There are multiple possible causes, which we'll look at next.
• Regurgitation: happens seconds after eating, or drinking water in more severe cases.

It's not preceded by retching. It can have several causes, some of which are:

1. Persistent right fourth aortic arch in puppies (a heart abnormality).
2. Hiatal hernia (part of the stomach becoming trapped in the chest cavity).

White foam vomiting from food intolerance

Vet visits for whitish or bilious vomit are common. This can be caused by food we've given them that didn't agree with them, eating too much grass, getting into the trash, and so on.

After an initial history and general physical exam, the vet should take an abdominal X-ray (ideally from two angles). If nothing obvious is found beyond gastritis and possible enteritis, symptomatic treatment and a bland diet will be prescribed while waiting to see how the dog responds.

Our dog should be watched for 12-48 hours. If they get worse, they'd need to go back for more definitive tests, such as an ultrasound.

Dogs vomiting foam from poisoning

Unfortunately, there are people who go around poisoning animals. Other times, we ourselves are the ones who put poison (rodenticides, mollusk killers, pesticides...) in the environment. Ingesting these substances usually causes foamy or whitish vomiting. They can also vomit after ingesting chemicals like bleach.

So, if you suspect poisoning, see a vet immediately so they can treat the poisoning.

How to prevent it? Keep your dog from eating anything they find on the street or out in the countryside, and be mindful of where pest-control substances might be. This will greatly reduce the risk of poisoning.

White foam vomiting from a foreign object

These kinds of vet visits aren't uncommon. This usually affects young dogs and puppies more, since they're the ones most likely to swallow objects and develop tracheal collapse, which causes them to foam at the mouth. Depending on the object swallowed, it can block the digestive tract's lumen (interior) to a greater or lesser degree, stopping food from moving forward and pushing it back up toward the mouth.

Additional tests such as an X-ray and/or ultrasound will always be needed after a history and general physical exam, to determine where the object is located. Depending on this, the resolving treatment will be surgery or endoscopy.

If we notice our dog is choking, or making sounds like they're choking, we should call the vet immediately, and if it's very urgent, follow their instructions to perform the Heimlich maneuver.

Gastric torsion also causes vomiting

A dog's stomach can twist on itself, closing off the entrance to the stomach (cardia) to a greater or lesser degree, causing retching or unproductive attempts to vomit.

The stomach, and therefore the left side of our dog's upper abdomen, will start to swell. This is a major veterinary emergency, since without treatment the animal is very likely to die. Depending on how severe the torsion is, surgery may be needed, and/or removal of the spleen due to tissue death from cut-off blood supply.

Preventing gastric torsion is quite simple: keep the dog resting before and after meals, avoid letting them drink a lot of water all at once, and split their daily food into 3 meals throughout their life, especially in large and giant breeds.

Other causes of white foam vomiting in a dog

Besides everything mentioned above, there are many conditions that can cause vomiting as one of their symptoms. Many of them require veterinary treatment. Some of these are:

• Too much water or food: as a precaution, we should always avoid letting our dog eat or drink right before or after intense exercise.
• Parvovirus in puppies.
• Coronavirus (enteric form).
• IBD (Inflammatory Bowel Disease).
• Kidney and liver diseases.
• Pyometra.
• Benign pyloric hypertrophy in some brachycephalic breeds.

What should I do if my dog vomits?

We should stay calm and not assume the worst. The main thing is to observe the symptoms — whether they vomit just once or repeatedly, whether the vomit contains food remains or objects, whether there's any blood, whether the liquid is yellowish, whitish, or brown, and so on.

We should note down all these details, since they'll be very helpful if we end up needing to see the vet. So the first step is simply to observe and take notes.

How do I know if I should take my dog to the vet?

We recommend that, whatever the cause of the vomiting, you call or visit your trusted vet to make sure it's nothing serious. And if it is something serious, to get the right treatment.

These are some symptoms that should put you on alert if they accompany the vomiting:

1. Weakness, apathy.
2. Diarrhea.
3. Persistent vomiting.
4. Blood or clots present.
5. Abdominal bloating.
6. Coughing.

Have you seen your dog vomit? Does your dog vomit constantly? Do they retch without managing to vomit? Do they vomit whitish foam even without having eaten anything? As you can see, there are many possible causes behind your dog vomiting, so better safe than sorry — check with your vet to make sure they're safe.