Why Is My Dog Being Sick?  

Rebecca from Brighton recently reached out, asking, "Why is my dog, Leo, always being sick?" 

Leo, a 3-year-old Golden Retriever, had been vomiting intermittently for the past week. Rebecca noted that while Leo seemed to bounce back quickly after each episode, the vomiting had become more frequent, with no apparent cause. She wondered if his new diet was a contributing factor or if something more serious was going on. 

After a few failed attempts to treat Leo’s symptoms at home, Rebecca sought advice from our veterinary team, and, with her permission, we thought it appropriate to include her story in our Ask A Vet series. 

In this article, our Chief Veterinarian and Omni Co-Founder, Dr Guy, will delve into the problem of the vomiting dog. 


If you’ve got a problem you’d like to be included in Omni’s Ask a Vet series online, just drop us an email to woof@omni.pet. 

Our Chief Veterinarian, Dr Guy MRCVS had this to say: 

Vomiting can be a concerning (and off-putting!) symptom in dogs, as it can point to a wide range of potential issues, from mild stomach upsets to more severe conditions. Understanding the underlying cause is crucial for ensuring your dog gets the right treatment.


Reasons Why Your Dog Is Being Sick

There are many reasons why vomiting can happen in dogs. Here are some of the most common causes:

  1. Pancreatitis, the inflammation of the pancreas and leakage of digestive enzymes into the abdominal cavity, which can severely impact digestion and cause vomiting. 
  2. Stomach upset, perhaps from eating something unusual on a walk or picking up a bug from the dog park. 
  3. Over-exercising or under-eating, particularly in some breeds.
  4. Bloat (Gastric dilatation volvulus) is a serious condition in dogs that occurs when the dog’s stomach twists and fills with gas or fluid, causing vomiting and potentially blocking the stomach’s entrance and exit. GDV can be fatal if left unchecked. 

Here’s a summary of the key points to watch out for:

  • Vomiting as a one-off may not be serious, but repeated vomiting is concerning.
  • If vomiting occurs alongside other symptoms like lethargy or a lack of appetite, it's important to consult a vet.
  • Chronic vomiting or vomiting every few days could indicate an underlying issue, and it’s important to seek veterinary advice for this. 

Why Is My Dog Vomiting?

Does My Dog Have Pancreatitis?

Vomiting Could Be a Sign of Pancreatitis

Pancreatitis occurs when the pancreas becomes inflamed, leading to digestive enzyme leakage into the abdominal cavity. These enzymes begin to digest surrounding tissues, causing pain and inflammation. This condition can range from mild to life-threatening and often leads to vomiting as the first obvious symptom.

Key signs of pancreatitis in dogs:

  • Loss of appetite
  • Abdominal pain (your dog may yelp when their stomach is touched)
  • Lethargy
  • Fever

Pancreatitis is typically associated with high-fat diets, but it can also be triggered by other factors like obesity, infections, or even trauma. Research indicates that certain dog breeds, including Miniature Schnauzers and Terriers, are more prone to developing pancreatitis due to genetic factors influencing fat metabolism .

How to Address Pancreatitis

If you suspect your dog has pancreatitis, immediate veterinary attention is necessary. Here’s what you can do:

  • Seek veterinary care: Your vet may prescribe medications to manage pain and inflammation, along with a low-fat diet.
  • Dietary changes: Switch your dog to a diet designed to prevent flare-ups, such as Omni’s plant-based food, which is naturally lower in fat compared to meat-based alternatives.

Vomiting Could Be a Sign of Stomach Upset 

A common reason for vomiting in dogs is a simple stomach upset. This can occur due to dietary indiscretion, such as eating something off the ground during a walk, or as a reaction to a sudden change in diet. While it’s typically mild, repeated vomiting can be concerning, especially if other symptoms are present.

Key signs of a stomach upset:

  • Vomiting more than once
  • Lethargy or lack of energy
  • Diarrhoea
  • Low-grade fever

Stomach upsets are usually temporary, but if the vomiting persists for more than a day or if it occurs frequently, it's important to seek veterinary advice to rule out more serious conditions like infections or chronic gastrointestinal diseases.

How to Address Stomach Upset

For mild stomach upsets, here’s how you can help your dog recover:

  • Rest your dog’s stomach: Remove food for 12-24 hours to give their stomach a break, while ensuring they stay hydrated.
  • Bland diet: Reintroduce food slowly with a bland diet or a nutritionally complete hypoallergenic plant-based option from Omni like Omni Sensitivity.
  • Vet consultation: If symptoms persist beyond 24 hours, seek veterinary advice.

Over-exercising or Underfeeding Some Dogs Can Induce Vomiting 

Are you walking your dog too much? 

Some dogs, particularly Maltese Terriers, Pugs, English Bulldog, Shih Tzus and other shorter, less athletic breeds, will vomit after too much exercise. These breeds typically have shorter airways and are less athletic than others, which can make them overheat or tire easily. Over-exercising can cause their stomachs to become unsettled, leading to vomiting.

Additionally, underfeeding your dog or exercising them on an empty stomach can also trigger nausea and vomiting. If your dog is not getting enough energy from food to fuel their activity, their blood sugar levels may drop, which can cause dizziness, weakness, and vomiting.

How to Prevent Exercise-Induced Vomiting

  • Moderate exercise: Limit the intensity and duration of walks, especially for breeds prone to overheating. Shorter, more frequent walks are better than long, strenuous outings.
  • Feeding before exercise: Make sure your dog eats a balanced meal 1-2 hours before exercising to maintain their energy levels and avoid nausea.
  • Hydration: Ensure your dog has access to fresh water during and after exercise to prevent dehydration, which can also lead to vomiting.

If you notice persistent vomiting after exercise, consult your vet to rule out any underlying issues.

Vomiting Could Be a Sign of Bloat (Gastric Dilatation-Volvulus)

Bloat is a life-threatening condition that involves the stomach twisting and trapping gas inside. It’s more common in large, deep-chested breeds like Great Danes or German Shepherds. One of the most alarming symptoms of bloat is frequent vomiting or dry heaving without actually bringing up any food.

Key signs of bloat:

  • Swollen abdomen
  • Repeated attempts to vomit with little to no success
  • Restlessness and difficulty breathing
  • Extreme lethargy

Bloat can develop rapidly and requires emergency veterinary care. Without prompt intervention, it can lead to death within hours due to restricted blood flow and damage to internal organs.

How to Address Bloat

If you notice any of these symptoms, take immediate action:

  • Emergency vet visit: Bloat is a medical emergency, and surgery is often required to save the dog’s life.
  • Prevention: Feeding smaller, more frequent meals and using slow-feeder bowls can reduce the risk of bloat.

Speak With a Vet If…

You should speak to a vet if:

  • Your dog is vomiting alongside other symptoms like lethargy, fever, or a swollen abdomen.
  • The vomiting persists for more than 24 hours or happens regularly over the course of several days.

If you notice any of these symptoms in your dog, don’t wait—book a free consultation with our vet team at Omni to get advice tailored to your dog’s needs.

Thoughts from Dr Guy MRCVS


As dog lovers and guardians, it’s natural to worry about our furry friends, especially when they display abnormal symptoms that can’t be easily explained. That’s why, when I founded Omni, I knew that I wanted to keep vet consultation free and accessible at the heart of the business. 


If you’re understandably worried about your dog, but you don’t think you need to take them to the vets urgently, I highly recommend getting some friendly, professional advice from one of our team. 


Book your appointment here


Explore some of the frequently asked questions in our Ask a Vet series 


Got a question for the Ask a Vet team?


Submit your question via email to woof@omni.pet. We’ll get back to you as soon as we can, and, if suitable, post the response here to help others, too! 



Disclaimer: Whilst the advice given here is based on medical experience from our experts, and scenarios we do encounter during our career - we do not give tailored or specific advice for individual pets - please seek assistance from your in person vet as a first point of call with any issues your pet is having which are a cause for concern as soon as possible.

FAQs

But aren’t dog’s carnivores?

Dogs are in fact nutritional omnivores as demonstrated by a robust scientific study published in the reputable journal Nature (1,2) in which it was shown that they have 30 copies of the AMY2B gene responsible for digesting plant-based foods.

They have also evolved relatively long intestines (21) (almost as long as humans) and relatively flat surfaces on their molars (31, 22) which they use for digesting and chewing a whole range of foods.

The common misconception that dogs are carnivores probably arises from the fact that they are classified in the order Carnivora but so are plenty of other species like bears, skunks, racoons who are omnivores and even the giant panda who thrives on a plant-based diet (20).

Is plant protein digestible to dogs?

Absolutely yes, studies which have looked at how much protein dogs can absorb from plant-based and fungi-based foods like soya and yeast demonstrated over 75% digestibility which is on par with meat-based foods (23, 24, 34, 35 & 25).

Both these protein sources also contain all 10 essential amino acids (36, 37) that dogs need to thrive.

Isn't there too much fibre in plant-based food?

The average amount of fibre in a commercial dog food diet is between 2-4%. omni’s plant-powered recipe has a fibre content of 3% which is on par with meat- based diets.

In our survey with over 200 dog owners, 100% reported that their dog’s stool consistency was either ‘normal’ or ‘perfect’ and there were no reports of any digestive upsets (data on file).

Can I mix omni with other meat-based diets?

We are proud that our recipes are nutritionally complete and so include everything your dog needs to thrive. This means omni can be fed as a sole ration. We also fully support a 'flexitarian approach' like meat free lunches or using omni as a mixer.

Every little helps to bring some of the health and environmental benefits of plant-power to meal times. Mixing omni with meat/fish will help to add variety into your dog’s diet whilst adding in healthy ingredients with a relatively low carbon footprint.

Can plant-based food provide the essential fatty acids dogs need?

All the essential fats and oils that dogs need, including omegas 3 and 6 are found in a variety of both meat and plant-based foods (31, 28).

omni’s recipe is rich in plant-based sources of these nutrients so your dog will get all the essentials they need.

I hear a lot about feeding raw meat, isn’t that better?

Feeding raw meat to dogs has become a very popular trend in recent years, but most vets will warn against this practise. This is because the cooking process is vital to help kill off dangerous bacteria like E coli, Salmonella and Campylobacter (9) that have necessitated several food recalls from the market and caused serious illness and even death in both dogs and their owners (40, 41, & 42).

There are also several worms and parasites that are only killed off when raw meat is cooked. Dogs are dogs, not wolves and thanks to their domestication over thousands of years, thankfully don’t need to hunt to get their grub nor do they need to eat raw meat, it's just not worth the risk.

References

1. Buff P.R., Carter R.A., Bauer J.E., Kersey J.N. (2014) Natural pet food: A review of natural diets and their impact on canine and feline physiology. J. Anim. Sci.;92:3781–3791. doi: 10.2527/jas.2014-7789


2. Axelsson E., Ratnakumar A., Arendt M.L., Maqbool K., Webster M.T., Perloski M., Liberg O., Arnemo J.M., Hedhammar A., Lindblad-Toh K. (2013) The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Nature; 495:360–364. doi: 10.1038/nature11837


3. The European Pet Food Industry (FEDIAF) Nutrition [ Accessed on 3 June 2021] Available online: http://www.fediaf.org/self-regulation/nutrition/


4. Gentle World Good Nutrition for Healthy Vegan Dogs [Accessed on 3 June 2021] Available online: http://www.webcitation.org/6ineIZmNQ


5. Peden J. (1999) Vegetarian Cats & Dogs. 3rd ed. Harbingers of a New Age; Troy, MT, USA


6. Semp P.-G. (2014) Master’s Thesis. Veterinary University of Vienna; Vienna, Austria: Vegan Nutrition of Dogs and Cats


7. Brown W.Y., Vanselow B.A., Redman A.J., Pluske J.R. (2009) An experimental meat-free diet maintained haematological characteristics in sprint-racing sled dogs. Br. J. Nutr.;102:1318–1323. doi: 10.1017/S0007114509389254


8. People for the Ethical Treatment of Animals (PETA) Dog Health Survey. [Accessed on 3 June 2021]


9. Marks S.L., Rankin S.C., Byrne B.A., Weese J.S. (2011) Enteropathogenic bacteria in dogs and cats: Diagnosis, epidemology, treatment, and control. J. Vet. Intern. Med.;25:1195–1208. doi:


10. Carrión P.A., Thompson L.J., Motarjemi Y., Lelieveld H., (2014) Food Safety Management: A Practical Guide for the Food Industry. Academic Press; London, UK:. pp. 379–395


11. Knight, A. and Leitsberger, M. (2016) Vegetarian versus meat-based diets for companion animals. Animals 6, 57.


12. Boyer C.I., Jr., Andrews E.J., deLahunta A., Bache C.A., Gutenman W.H., Lisk D.J. (1978) Accumulation of mercury and selenium in tissues of kittens fed commercial cat food. Cornell Vet.;68:365–374.


13. Anonymous. Your Pet’s Dog Food Could Be Dangerous. [Accessed on 8 December 2014] Available online: http://www.wavy.com/Global/story.asp?S=1018127&nav=23iiCT4S.


14. Porecca K. (1995) Personal letter to James Peden re: Interview of University of California (Davis), North Carolina State University, and University of Guelph Researchers investigating the connection between dilated cardiomyopathy and diet


15. Perry T. What’s Really for Dinner? [Accessed on 7 July 2016] Available online: http://www.webcitation.org/6ipEL5YVR.


16. https://www.bordercolliefanclub.com/bramble-the-vegan-dog-lives-to-189-years/


17. https://aminoapps.com/c/vegan/page/blog/vegan-dog-lives-to-27-years-of-age/N4ai_MuaRE5qNoYVN1DN85ap0GVjz3j


18. https://v-dog.com/blogs/v-dog-blog/vegan-diets-for-dogs-what-about-longevity


19. https://www.fediaf.org/39-prepared-pet-foods/80-understanding-labels.html


20. https://vetnutrition.tufts.edu/2016/07/vegan-dogs-a-healthy-lifestyle-or-going-against-nature/

21. https://www.petmd.com/dog/nutrition/7-interesting-facts-about-your-dogs-digestive-system

22. http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/dogpage.html

23. Félix AP, Zanatta CP, Brito CB, et al. (2013) Digestibility and metabolizable energy of raw soybeans manufactured with different processing treatments and fed to adult dogs and puppies. J Anim Sci;91:2794–2801.


24. Carciofi A, de-Oliviera L, Valério A, et al. (2009) Comparison of micronized whole soybeans to common protein sources in dry dog and cat diets. Anim Feed Sci Technol;151:251–260.

25. Yamka R, Kitts S, Harmon D. (2005) Evaluation of low-oligosaccharide and low-oligosaccharide low-phytate whole soya beans in canine foods. Anim Feed Sci Technol;120:79–91.

26. Hill D. (2004) Alternative proteins in companion animal nutrition, in Proceedings. Pet Food Assoc Canada Fall Conf;1–12

28. Hazewinkel HA, Tryfonidou MA. (2002) Vitamin D3 metabolism in dogs. Mol Cell Endocrinol;197:23–33.
Boland R, Skliar M, Curino A, et al. (2003) Vitamin D compounds in plants. Plant Sci;164:357–369.

29. Jäpelt RB, Jakobsen J. (2013) Vitamin D in plants: a review of occurrence, analysis, and biosynthesis. Front Plant Sci;4:136

30. Knight, A. and Leitsberger, M. (2016). Vegetarian versus meat-based diets for companion animals. Animals 6, 57.

31. Dodd SAS, Adolphe JL, Verbrugghe A. (2018) Plant-based diets for dogs. J Am Vet Med Assoc. Dec 1;253(11):1425-1432. doi: 10.2460/javma.253.11.1425. PMID: 30451617.

32. https://www.petmd.com/dog/wellness/evr_dg_how_long_do_dogs_live [Accessed 2 June 2021]

33. https://www.utep.edu/leb/pleistnm/stuff/stuff2.htm [Accessed 2 June 2021]

34. M S Martins, N K Sakomura, D F Souza, F O R Filho, M O S Gomes, R S Vasconcellos, A C Carciofi (2014) Brewer’s yeast and sugarcane yeast as protein sources for dogs, J Anim Physiol Anim Nutr (Berl) 2014 Oct;98(5):948-57. doi: 10.1111/jpn.12145.

35. Christina Golder, James L Weemhoff, Dennis E Jewell (2020) Cats Have Increased Protein Digestibility as Compared to Dogs and Improve Their Ability to Absorb Protein as Dietary Protein Intake Shifts from Animal to Plant Sources 24;10(3):541. doi: 10.3390/ani10030541.

36. Henkel J. (2000) Soy. Health claims for soy protein, questions about other components. FDA Consum ;34(3):13–15,18–20.

37. Yalçin, Sakine & Erol, H & Özsoy, Bülent & Onbaşılar, I. (2008) Effects of the usage of dried brewing yeast in the diets on the performance, egg traits and blood parameters in quails. Animal : an international journal of animal bioscience. 2. 1780-5. 10.1017/S1751731108003170.

38. Rosser EJ (1993) Diagnosis of food allergy in dogs. Journal of the American Veterinary Medical Association; 203(2):259-262.

39. Mueller RS, Olivry T, Prélaud P. (2016) Critically appraised topic on adverse food reactions of companion animals: common food allergen sources in dogs and cats. BMC Vet Res.12:9. Published 2016 Jan 12. doi:10.1186/s12917-016-0633-8

40. https://www.kentlive.news/whats-on/shopping/salmonella-fears-spark-urgent-recall-4328262

41. https://www.food.gov.uk/news-alerts/alert/fsa-prin-31-2020

42. L. Martinez-Anton, M. Marenda, S.M. Firestone, R.N. Bushell, G. Child, A.I. Hamilton, S.N. Long, M.A.R. Le Chevoir (2018) Investigation of the Role of Campylobacter Infection in Suspected Acute Polyradiculoneuritis in Dog


43. https://www.foodsafetynews.com/2018/10/four-stec-infections-one-person-dead-after-exposure-to-raw-pet-food/

44. https://www.theguardian.com/science/2018/jan/12/scientists-criticise-trend-for-raw-meat-pet-food-after-analysis-finds-pathogens

45. https://news.cancerresearchuk.org/2015/10/26/processed-meat-and-cancer-what-you-need-to-know/

46. D.F. Merlo, L. Rossi, C. Pellegrino, M. Ceppi, U. Cardellino, C. Capurro, A. Ratto, P.L. Sambucco, V. Sestito, G. Tanara, V. Bocchini (2008) Cancer Incidence in Pet Dogs: Findings of the Animal Tumor Registry of Genoa, Italy
https://doi.org/10.1111/j.1939-1676.2008.0133.x , journal of veterinary internal medicine

47. https://www.pfma.org.uk/_assets/docs/White%20Papers/PFMA-Obesity-Report-2019.pdf

48. https://www.pfma.org.uk/grain-free-factsheet

49. https://fediaf.org/images/FEDIAF_Nutritional_Guidelines_2020_20200917.pdf

50. https://www.ksvdl.org/resources/documents/dcm-forum/Confidential-Abstract-for-release-October-14-2020-Final.pdf

51. https://www.ksvdl.org/resources/documents/dcm-forum/DCM-Forum-SolomonOpening-Remarks.pdf

52. https://stpetersbark.com/finally-theres-no-evidence-linking-grain-free-diets-and-non-hereditary-heart-conditions-in-dogs/

53. Okin GS (2017) Environmental impacts of food consumption by dogs and cats. PLoS ONE 12(8): e0181301. https://doi.org/10.1371/journal.pone.0181301

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