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Why is my large dog regurgitating undigested food? What tests?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Large (61lb +) | Female | unspayed | 40 lbs

My 4 Yr old Tibetan Mastiff hs bn throwing up undigested food, especially solids 4a month now.She ws given antibiotic shots & is being given probiotic powder.No proteins allowed. Looks more like regurgitation than vomiting. No bile.Clear slimy liquid. Wants to eat grass all the time.Shes on a liquid diet(soups).There r no adequate veterinary facilities where I am in India. Bt we r planning to tk her 2a city which hopefully wl hv answers.Wht shud we be looking for & what tests do you suggest? TY

3 Answers

Most Helpful Answer

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Answered By Sarah Derksen, DVM

Veterinarian

Published on January 13th, 2018

Hi. Regurgitation differs from vomiting in that the expelled material almost always originates from the esophagus—the tube that moves food, water and saliva from the mouth down into the stomach. Vomiting is preceeded by retching noises, where as regurgitation is a passive event where you only hear a noise as the material comes up. The most common cause of regurgitation is megaesophagus. Megaesophagus is a generalized enlargement of the esophaguswith a decreased to absent motility which is required for moving food and liquid down to the stomach. It is diagnosed most commonly by a lateral x-ray of the chest where the esophagus goes from the beginning of chest area into the stomach. If it is vomiting, it is unfortunately a vague sign that can occur from many possibilitites.  It can be from a dietary indiscretion, a food sensitivity, a GI infection,  pancreatitis, metabolic and endocrine conditions, foreign bodies in the intestines, and more.   The best thing for vomiting would be to get blood work and abdominal x-rays done. Good luck

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    Answered By Justin Plunk, DVM

    Veterinarian

    Published on September 29th, 2017

    Hi, thanks for using Petco Pet Education Center, formerly Petcoach! Shepherd dogs of any breed tend to have sensitive stomachs and/or intestinal tracts, but I do share your concern that your dog could have something like megaesophagus. Differentiating between vomiting and regurgitation is often difficult, and it is possible she does both. Sometimes, chest x-rays are enough to determine if megaesophagus is present, though the absence of seeing such changes on plain film radiography does not rule-out megaesophagus completely. Sometimes, a barium swallow test with fluoroscopy is required for a definitive diagnosis. Then, if she does have megaesophagus, an underlying cause should be sought out and addressed if possible to achieve best possible management of her condition. Whether she has megaesophagus or not, abdominal x-rays would be a good idea of the vomiting and/or regurgitation persist. An abdominal ultrasound may be necessary as well to achieve a more refined diagnosis. In the meantime, I would recommend elevating her food as high as you can where she can still eat it, probably around 8-12 inches off the floor for a dog her size. Also, you can soften her dry food by applying water to it and see if she is able to keep it down. Hope this helps!

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    Answered By Ann Dion, DVM

    Veterinarian

    Published on November 29th, 2018

    Hello and welcome to Petco Pet Education Center, formerly Petcoach. I am sorry that Rambo isn't feeling well. Mega-esophagus is a very tricky disorder. Mega-esophagus can be caused by various underlying diseases including cancers, hypothyroidism, myasthenia gravis, and other conditions. I would discuss with your vet about testing for these, as some are treatable. Mega-esophagus can also be primary, or just aquired. In this case there isn't much treatment, just management. Management involves feeding meat-ball shaped foods from an elevated position, and water being up in an elevated position. It is also important to monitor for signs of aspiration pneumonia (food going into the lungs), as this is a common complication that occurs, and can lead to life-threatening pneumonia. If aspiration pneumonia is suspected then antibiotics are sometimes required. Management of this condition can be very difficult and tricky, and will require a good relationship and unfortunately frequent relationship with your vet. Other medications to help or consider include proton pump inhibitors (omeprazole), anti-nausea medications (maropitant, ondansetron), pro-kinetic medications (metoclopramide). Talk to your vet about these classes of medications. I hope Rambo feels better soon.

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