Worms in a Dog’s Vomit: Why Is My Dog’s Puke Full of Worms?
Every time my dog throws up, I make sure I scrutinize the contents. When I discover something weird-looking, first I try to think of what they have or might have eaten.

Over the years, I found all sorts of things from sticks, rocks, toy fragments, plastic pieces … even an accidentally swallowed sock once. Fortunately, with our dogs, all these things found the natural way out of the system with no consequences.
But what if your dog’s vomit looks like they’ve just eaten spaghetti noodle soup?
If your dog indeed ate some spaghetti and threw them up, still recognizable, it can mean a variety of things, which we’ll cover next time. This time we’re talking about what looks like spaghetti but isn’t – worms.
Worms in vomit? Yuck!
Well, yes, but however yucky that is, the bigger problem is where they came from–inside your dog. Of course, that’s where you really don’t want any. But how could worms survive in the stomach? While there is such a thing as stomach worms, when you find spaghetti-like worms in your dog’s vomit, you are most likely looking at intestinal parasites instead, namely roundworms.
How would intestinal worms get into vomit?
They should show up in the poop, come out that way, no?
Dogs are most commonly infected with roundworm by ingesting the eggs in another dog’s poop. After being swallowed, the eggs undergo a strange but fascinating lifecycle involving migration through the wall of the intestine into the liver and the lungs. They are then coughed up and swallowed so they can make their way to their home in the small intestine.
Adult worms actively wriggle upstream, against the efforts of the intestines to push everything downwards towards the pooping end. They usually stay in the intestines but sometimes manage their way up into the stomach. That’s how they can make their way into the vomit.
Roundworms are most common in puppies, but that doesn’t mean an adult dog could get infected.
IA dog or puppy who has just been dewormed is likely to throw up a bunch of worms. If they’re acting normally, vomiting of the dead worms can occur.
Do see a veterinarian if your dog is throwing up worms and has not been dewormed recently.
Why worry about roundworms?
Roundworms are not just gross but can become a serious health threat. Not only do they rob your dog of nutrients, but complications include intestinal blockage or pneumonia.
Other symptoms
Besides finding worms in the poop or vomit, other signs can include:
- diarrhea
- changes in appetite
- lethargy
- swollen belly
- weight loss,
- and even coughing
Puppies are most vulnerable, so screening and the deworming regimen is quite rigorous. Regarding adult dogs, I don’t like fixing a problem I don’t have. However, I do believe it is essential to have the stool checked regularly, even if I don’t see any evidence of parasites.
Phew am I relieved I have not had this problem, great post though and always good to know
Thankfully, I haven’t encountered worms with Henry. I just had a parasite test done on him and it came back negative. Although, I always watch his poop very carefully. He has only thrown up a couple of times since I’ve had him and that was only foam.
But I did have a childhood dog who would find the grossest things and end up with parasites. I don’t recall him throwing up worms. However, he did have to be treated for parasites yearly as I remember. He definitely had a nose for decaying things and maggots/larva. Why???? YUCK!!!! Always was gross. But he’d return to his old behaviors no matter what we did to deter him. Crazy pup!
Great article on the importance on what to look for with worms in dogs. In sharing it with all my dog parents.
Worms is something dog owners need reminding about because they may not even think to look at what their dog is doing. Clearly monitoring a dog’s health is vital and that includes ‘both ends’ with what comes out (as well as what goes in!)
I appreciate the checklist of symptoms too. Knowing what to look for would be a help if I encountered a challenge like worms.