Diarrhea and Vomiting in Dogs: When to Wait and When to Act

In brief

There are five things you should know when your dog has diarrhea or is vomiting. First, many acute cases are mild and improve within a few days – what matters is recognizing the exceptions. Second, certain accompanying signs turn it into an emergency right away, above all unproductive retching, black tarry stool, marked weakness, and vomiting in a puppy. Third, the blanket rule of withholding food from every dog with diarrhea for 24 hours is now considered outdated – food is part of the treatment, not its opposite. Fourth, an antibiotic is generally not needed for uncomplicated diarrhea; in one controlled study, metronidazole shortened the duration by about a day and a half on average – while also altering the gut flora, in part for a longer period. Fifth, you can almost always offer water – the exception is suspected bloat (gastric dilatation-volvulus).

Diarrhea and vomiting are among the most common reasons dogs are brought to the vet – and among the topics where the most goes wrong at home. This article sorts out when you can wait, when you need to go in, and what actually helps in the meantime.

Note: This article is general information and does not replace a veterinary examination. For puppies and for older dogs or dogs with existing conditions, the threshold is much lower – they are seen sooner, not later.

👉 Prevention and health in one place: Dog health basics

1. When it is an emergency

This comes first because it is where the only truly time-critical decision lies.

• Unproductive retching – the dog tries to vomit, but nothing comes up. In large dogs, this raises urgent suspicion of bloat (gastric dilatation-volvulus).
• Black, tarry stool or vomit that looks like coffee grounds – both point to bleeding in the upper digestive tract.
• Larger amounts of fresh blood in the stool, combined with weakness.
• Marked weakness, collapse, pale gums.
• A distended, hard belly.
• Persistent vomiting in which even water won't stay down.
• Suspected foreign body or suspected ingestion of poison, chocolate, grapes, or medication.
• Vomiting or diarrhea in a puppy, an older dog, or a dog with existing health conditions – here, you don't wait.

Everything else can be watched, but not indefinitely: if it lasts longer than about two days, gets worse, or a fever develops, your dog needs to see the vet.

👉 If your suspicion points in that direction: Bloat (GDV) in dogs

👉 If you suspect your dog has eaten something toxic: Suspected poisoning in dogs

2. Wait or go in – the cases in between

The previous section describes the cases where there is no question. In between lies the large remainder, and that is where it is decided whether someone goes in too early or too late. Three factors help you assess the situation.

2.1 Overall condition outweighs symptom severity

This is the single most important distinction, and it is rarely stated this clearly: a dog with severe diarrhea who is eating, drinking, alert, and eager to go for a walk is in a completely different situation from a dog with mild diarrhea who withdraws and won't get up.

If you look only at the stool, you will draw the wrong conclusions – in both directions. So the question is not "how bad does it look?" but "how is he doing with it?".

2.2 Who the dog is shifts the threshold

The same symptoms mean different things in different dogs.

Puppies and very small dogs have hardly any reserves. They can quickly become dehydrated and hypoglycemic. Here you don't wait – they are seen the same day.

Older dogs and dogs with existing conditions – kidney disease, heart disease, diabetes, Cushing's – likewise. In these dogs, a gastrointestinal infection can throw the underlying disease off balance as well.

Dogs on long-term medication, especially anti-inflammatory pain relievers: here, vomiting or diarrhea is a reason to call the clinic before the next tablet is given.

Large, deep-chested dogs with unproductive retching need to go to an emergency clinic immediately – that is the case from section 1.

A healthy adult dog of medium size, on the other hand, is the case in which watching and waiting is reasonable.

2.3 The clock is running

As a rough guide, as long as none of the signs from section 1 are present: two days is a reasonable observation period for a bright, alert adult dog. If anything gets worse, a fever develops, or the dog can't keep water down, the waiting ends immediately.

And the rule that stands above everything else: if you are unsure, call. A phone call to the clinic costs nothing and answers exactly this question – that is what it is there for.

3. What the stool tells you

Consistency and color narrow down the cause without proving it. A photo is surprisingly helpful at the vet – far more precise than any description.

Watery, large volumes, no straining: points more toward the small intestine. Typical with a change of food, infections, or eating something spoiled.

Small amounts, frequent passing, with straining, often with mucus and bright red blood: more likely the large intestine. It looks dramatic but is usually less threatening than it seems – fresh blood from the large intestine is something different from tarry stool.

Black and tarry: digested blood from the stomach or upper small intestine. Always have it checked.

Very pale or greasy-looking: can point to problems with fat digestion, for example with exocrine pancreatic insufficiency.

With vomiting, the most important distinction is a different one: if food comes back up undigested, sausage-shaped, and without effort shortly after eating, that is not vomiting but regurgitation – a backflow from the esophagus. It has different causes and needs to be investigated separately.

4. The most common causes

Diet-related: switching food too quickly, intolerance, overly fatty table scraps, eating something spoiled on a walk. Diet-related causes are among the most common triggers.

Parasites: Giardia, worms, and coccidia, especially in young dogs and in dogs imported from other countries.

Infections: viruses such as parvovirus, bacteria, and often mixed pictures.

Stress: the gut responds directly to tension. A move, a vet visit, New Year's Eve fireworks, or a separation can trigger diarrhea without anything else being wrong.

Medications, especially anti-inflammatories and antibiotics.

Diseases of other organs: kidneys, liver, pancreas, thyroid. That is why recurrent diarrhea is not automatically just a gut question.

👉 Why the gut responds to stress: The gut–brain axis in dogs

👉 The classic among triggers: Foods that are toxic to dogs

4.1 When several dogs are affected

If several dogs in the household fall ill at the same time or one after another, the list of suspects shifts considerably – and a few additional measures are called for.

Two possibilities come to the fore: they all ate the same thing – a batch of food, something found in the yard, table scraps – or a contagious pathogen is involved. From the outside, both look the same, and telling them apart is a job for the vet.

What you can do right away: pick up feces in the yard and in the house promptly, keep bowls separate and wash them in hot water, wash bedding, and wash your hands after cleaning up. Some pathogens – Giardia, for example – persist in the environment and cause constant reinfection as long as nothing is done about it there.

And the zoonosis question: some of these pathogens can also affect people. For healthy adults, the risk is low; with small children, pregnant women, and people with weakened immune systems, hygiene at this point is no minor matter.

Important for the vet visit: say explicitly that several animals are affected, and since when for each. The order in which they fell ill is information that helps determine the suspected diagnosis.

5. The reflex to withhold food: current thinking

"Don't feed anything for twenty-four hours so the gut can recover" – hardly any piece of advice is passed on more often. What is meant is a complete break from food, often called a "fasting diet." And hardly any piece of advice has turned around so completely.

The scope matters here: what has become outdated is the blanket application to every dog with diarrhea. That a short break from food can make sense in an individual case – for example after heavy vomiting, so the stomach can settle – remains unaffected. What goes away is the rule, not the option.

The logic behind it sounds plausible: if nothing goes in, nothing has to be processed. But the gut doesn't work that way. The cells of the intestinal lining get a considerable part of their nourishment directly from the gut contents, not via the bloodstream. If that supply is cut off, the very tissue that is supposed to be regenerating gets nothing. Prolonged fasting can therefore weaken the mucosal barrier rather than protect it.

The current approach is therefore: feed again early, but feed the right thing. The treatment is not leaving food out; it is the food itself. A controlled study in dogs with acute colitis investigated exactly this and concluded that nutritional management was superior to the antibiotic.

In practice, this means: a short pause of a few hours after acute vomiting makes sense so the stomach can settle. A whole day without food does not – in puppies and very small dogs it is even dangerous, because their blood sugar drops.

6. Antibiotics for diarrhea: what the studies show

The second reflex is the antibiotic, usually metronidazole. Here, too, a closer look is worthwhile, and the result is more nuanced than the usual camps make it out to be.

In a randomized, double-blinded, placebo-controlled study in dogs with acute, nonspecific diarrhea, the median time to resolution was 2.1 days with metronidazole versus 3.6 days with placebo (Langlois et al. 2020). So the drug works – but the gain is around a day and a half for a condition that resolves on its own anyway.

This comes at a price that the authors themselves point out. Metronidazole alters the gut flora of healthy dogs considerably, and some of these changes persist for an undetermined period. On top of that comes the contribution to antimicrobial resistance, which reaches beyond the individual dog. The authors explicitly state that dietary changes or probiotics might achieve comparable effects and thus make an antibiotic unnecessary.

And the evidence is not uniform. In a second randomized, double-blinded, placebo-controlled trial in 60 dogs with acute diarrhea, three groups were compared: a probiotic, metronidazole, and a placebo. The time to acceptable stool consistency was 3.5 days with the probiotic, 4.6 days with metronidazole, and 4.8 days with the placebo – there was no statistically significant difference (Shmalberg et al., 2019). The authors state that their results do not support the widespread use of metronidazole in these dogs.

Two studies, two different results – that is the honest state of the evidence. What both have in common: in all groups, the cases resolved within a few days, even without treatment. A proven, reliable benefit of routinely giving antibiotics for uncomplicated diarrhea cannot be derived from them.

None of this amounts to rejecting antibiotics; it is a question of indication. They make sense for bloody diarrhea with fever and poor overall condition, for confirmed bacterial pathogens, and when there are signs that bacteria have crossed the intestinal wall. For an otherwise bright, alert dog with two days of diarrhea, they generally do not.

If one is prescribed for your dog, the question "What exactly is this targeting?" is entirely legitimate – and a good clinic will answer it.

7. What helps instead

An easily digestible bland diet, in small portions. Several small meals spread over the day put less strain on the gut than two large ones. Low-fat, highly digestible combinations have proven themselves; there are commercial veterinary diets formulated for exactly this purpose.

Return to the usual food slowly, mixing it in over several days, not from one day to the next.

Probiotics can have a favorable effect on the course. The evidence is mixed, but they are low-risk and have been associated with faster recovery in several studies.

Rest. Short potty walks instead of long outings, and no training that gets your dog worked up.

And something that is often overlooked: a sudden change of food is among the most common triggers you can influence yourself. The gut is home to a bacterial community that has settled in over weeks and is adapted to the usual food. If you switch overnight, this community gets thrown out of sync – even if the new food is objectively better. Mixing gradually over seven to ten days costs nothing and can prevent many of these cases. The same applies to switching to a veterinary diet and back again.

What does not help: home remedies from your own medicine cabinet. Human antidiarrheal drugs interfere with gut motility, which can be counterproductive with an infection, because pathogens may stay in the gut longer. And pain relievers such as ibuprofen are extremely dangerous for dogs; acetaminophen (paracetamol), too, should only be given to a dog on veterinary instruction.

👉 Why your medicine cabinet is off-limits: Human medications and dogs

7.1 Bland diet: what it means and what it doesn't

"Easily digestible, low-fat, small portions" is correct but stays abstract. Because a lot goes wrong in putting it into practice, here are the points that matter.

Low-fat is the most important property, and it is the one most often missed. Chicken with the skin, fatty ground meat, or rice with a splash of oil count as a bland diet for many people – for an irritated gut, they are not. Suitable options are skinless chicken breast, low-fat quark or cottage cheese, and well-cooked potato or rice.

Few ingredients. Two or three, not eight. The fewer ingredients there are, the easier it is to pin down later what caused the problem.

Small portions, often. Four to six small meals over the day instead of two large ones. A large amount at once can set off the vomiting again.

Lukewarm rather than cold. Food straight out of the refrigerator is often less readily accepted.

No salt, no spices, no onions. This applies especially if you cook yourself – leftovers from your own meals are not a bland diet just because they taste bland.

A word on veterinary diets from the clinic: they are formulated for exactly this purpose, the composition is right without any calculating, and they spare you a two-step transition. If you cook yourself, you should know that a homemade bland diet is fine for a few days – as longer-term feeding, it is not balanced.

And the way back counts too. The usual food is mixed in over several days, not from one day to the next. A relapse after the diarrhea has cleared up can be due to exactly this – and not to the illness.

8. Bloody diarrhea: a condition of its own

One condition deserves a separate mention, because it looks dramatic, progresses quickly, and is often treated incorrectly: acute hemorrhagic diarrhea syndrome.

The typical case is a dog who was still fine in the morning and within hours passes large amounts of bloody diarrhea, often resembling raspberry jam, frequently with vomiting as well. Small and medium-sized breeds are predominantly affected, and the dog becomes noticeably weak within a short time.

The real problem is not the blood lost to the outside, but the loss of fluid into the intestine. The circulation lacks volume, while the solid components of the blood increase in proportion – a finding that bloodwork shows immediately. Left untreated, this can lead to shock, and within a few hours.

Treatment therefore consists primarily of intravenous fluids, not of drugs against the diarrhea. And here, too, restraint with antibiotics applies: in a prospective, randomized, blinded study, adding metronidazole brought no demonstrable benefit for this condition. Antibiotics are reserved here for cases with signs of sepsis – high or very low temperature, poor circulation, abnormal bloodwork.

What this means for you: large amounts of bloody diarrhea in a dog who is rapidly getting weaker is not a case for watching overnight. With timely fluid therapy, the outlook is good.

9. Fluids: the real risk

The problem is not the diarrhea itself but the loss of water – and in small dogs and puppies, that happens fast.

Water should generally be available. The exception is suspected bloat – and there, the crucial point is not the water but that the dog needs to go to an emergency clinic immediately. Not giving anything by mouth in that situation is a supporting measure on the way there, not a treatment step.

The same goes for a dog who seems seriously ill or can't keep even water down: then the question is no longer how much he should drink, but how quickly he is seen. With vomiting, it helps to offer small amounts often instead of a large bowl, because a large amount at once triggers vomiting again.

Signs of dehydration are sunken eyes, tacky gums, and a skin fold at the back of the neck that returns slowly. In puppies, listlessness is added to that. All of these are reasons to have your dog seen right away – you can't overcome marked dehydration at home; that takes intravenous fluids.

9.1 Assessing dehydration – and why that has its limits

The signs from the previous section can be checked at home, and it is worth knowing how – and where the check becomes unreliable.

The skin fold. Lift a fold of skin at the back of the neck or between the shoulder blades and let go. With adequate hydration, it falls back immediately. If it stays up or returns slowly, fluid is missing. The limitation: in very thin dogs and in older dogs, the fold stays up longer even without dehydration; in overweight dogs, it falls back quickly despite a deficit.

The gums. They should be moist and smooth. Tacky or dry is a sign. If you press briefly on them with your finger, the color should return within about two seconds – if it takes noticeably longer, that is a circulation sign and no longer a case for waiting.

The eyes. Eyes that look sunken are a late sign.

And in puppies, additionally: listlessness, a cool mouth, and weakness. In them, everything happens faster, and the hands-on checks are less reliable.

The point that stands above everything else: these checks detect marked dehydration. They do not reliably detect early dehydration. So they are useful for confirming an existing concern – not for giving the all-clear.

And if one of these signs applies, the next step is no longer offering water but going in. You can't overcome marked dehydration with a water bowl.

10. When a fecal sample makes sense

For a single, brief bout of diarrhea, usually not. It becomes worthwhile when the diarrhea lasts longer than a few days or keeps coming back, when a young dog is affected, or when the dog comes from another country.

Two things are important here. Samples are collected over three consecutive days, because pathogens are shed intermittently. And the request has to state what is being tested for – Giardia, for example, are not worms and are detected with a separate test that a standard examination for worm eggs does not include.

👉 What a fecal test can and can't do: Deworming or fecal testing?

11. What happens at the vet

For a bright, alert dog with brief diarrhea, the vet will often deliberately not run many tests – that is not negligence but appropriate. The workup increases with the warning signs.

It starts with the history and physical examination: how long, how often, what it looks like, what he might have eaten, which medications, which existing conditions. Plus palpation of the abdomen, temperature, gums, and assessment of hydration.

Depending on the picture, this is followed by: bloodwork with organ values – it shows hemoconcentration, inflammation, and whether the kidneys or liver are involved. A fecal examination for parasites and, depending on the suspicion, for viruses. An abdominal ultrasound, which assesses foreign bodies, changes in the intestinal wall, and the pancreas. An X-ray if a foreign body or a displacement is suspected.

Good to know: an ultrasound does not replace an X-ray and vice versa – the two show different things. And normal bloodwork does not rule out a foreign body.

Treatment then depends on the findings: intravenous fluids for dehydration, anti-nausea medication for persistent vomiting, pain relief for abdominal pain, a veterinary diet – and antibiotics only when there is a sound indication.

11.1 What to bring to the appointment

With this topic, the history is the most valuable information, and it is created at home. Five things make the appointment considerably more productive.

A photo of the stool. It sounds unappetizing and is more precise than any description – color, consistency, and admixtures are unambiguous in a picture.

A timeline. When did it start, how often since then, how has it changed. A dog with six bowel movements on the first day and two on the second is a different case from the reverse.

What he has eaten – including anything he might have found on walks, anything visitors gave him, and anything that disappeared from the trash can.

The complete list of medications, including dewormers, tick preventives, and supplements.

The fecal sample, if a test is on the table – collected as described in section 10. Call ahead to ask whether it is needed; that saves you a second trip.

And one point that is often forgotten: if several dogs live in the household, mention whether the others are affected too. That shifts the suspected diagnosis considerably – otherwise, food they all ate and a contagious pathogen look the same.

12. When it becomes chronic

If diarrhea lasts longer than about three weeks or keeps coming back in episodes, it is called a chronic course – and then the approach changes fundamentally.

Now the goal is no longer to treat symptoms but to search: fecal examinations, bloodwork including organ values and thyroid, ultrasound, special blood values for the pancreas and vitamin absorption, often a controlled elimination diet over several weeks, and in some cases a tissue biopsy from the intestine.

What matters here is patience in the right place: an elimination diet only works if truly nothing else is fed – no treats, no chews, no pill wrapped in sausage. A common reason for an unclear result is not the diet itself but what was given on the side.

12.1 What you contribute during a chronic course

The workup stretches over weeks to months, and a considerable part of the material the vet works with is created at your home.

The stool diary. Date, number of bowel movements, consistency on a simple scale from firm to watery, admixtures. Two lines a day. This shows whether a measure has worked – your impression is particularly misleading here, because chronic diarrhea comes in episodes and every improvement looks like a success at first.

Weight, weekly. It is one of the most informative single measures in chronic intestinal disease. A dog whose stool is improving but who keeps losing weight is not on the right track.

Sticking to the diet. The sentence from the previous section deserves elaboration, because this is where many workups fail: no treats, no chews, no pill in sausage, no flavored toothpaste, no chewable dewormer, nothing from the table – and nobody in the household making an exception.

And write down slip-ups instead of keeping quiet about them. A documented slip extends the diet by a few days. One that goes unmentioned can make the result worthless, and nobody knows why.

What you gain from this is time. A carefully kept record often spares you a repeat round – and that takes weeks.

13. What can be prevented

A considerable proportion of acute cases arise from something that can be influenced. Five points cover most of them.

13.1 Scavenging on walks

One of the most common triggers you can influence yourself. A dog who eats along the roadside picks up spoiled food, along with other animals' feces – and with them, parasites, which according to section 4 are among the common causes.

What helps is a well-built "leave it" cue and, where necessary, a muzzle the dog has been conditioned to accept. Both are a matter of training, not of strictness – a dog who reliably leaves things gets more off-leash time, not less.

13.2 Changing food

Mixed in over seven to ten days, not from one day to the next. This also applies to a switch within the same brand and to the transition to puppy or senior food.

13.3 What comes from the table

Fatty leftovers are the classic trigger – and in an unfavorable case, not just for diarrhea but for pancreatitis. This applies especially on holidays, when several people hand out food independently of one another.

13.4 Parasite control

A plan instead of a reflex: how often your dog is tested or treated depends on age, living situation, contacts, and origin. For dogs adopted from rescues abroad and for young dogs, the threshold is lower.

13.5 Stress

The point that is most underestimated in everyday life. The gut responds directly to tension, and in some dogs diarrhea is the first and clearest sign that something was too much.

If you notice a pattern in your dog – diarrhea after visitors, after encounters with other dogs, after a weekend with lots of appointments – don't dismiss it as a sensitive stomach. It can be feedback about the load your dog is under, and it belongs in your planning.

A notebook kept for a few weeks makes such patterns visible. Without records, every incident gets explained on its own – with records, you see what connects them.

14. What you can do at home

Document. A photo of the stool, notes on frequency, consistency, onset, and everything your dog might have eaten in the last few days – including what he picked up on walks.

Take his temperature if you can. A fever shifts the assessment considerably.

Watch his overall condition, not just the stool. A dog with diarrhea who is eating, drinking, and alert is something completely different from one who withdraws.

Separate dogs in a multi-dog household as long as the cause is unclear, and pay attention to hygiene – some pathogens are transmissible, a few of them to people as well.

Always change food slowly, mixing it in over seven to ten days. That can prevent many diet-related cases from the outset.

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15. Limits of the evidence

The metronidazole study cited included 31 dogs. That is a small sample size, and the effect of around a day and a half should be read with corresponding caution – in both directions.

On the question of withholding food, there are no large controlled comparative studies in dogs. The recommendation to feed again early is based on the physiology of the intestinal lining, on findings from human medicine, and on studies on the effectiveness of veterinary diets – not on a direct "fasting versus feeding" comparison in dogs.

For probiotics, the evidence is mixed: products differ considerably in strains and bacterial counts, and results cannot be transferred from one to another.

And matching stool consistency to the small or large intestine is a clinical rule of thumb that helps with sorting and does not replace a diagnosis.

On the structure of the evidence: the two metronidazole studies are randomized, blinded, and placebo-controlled – a methodologically strong study design. Their limitation lies in their size: 31 dogs in one of them is few, and a difference of a day and a half can be read from it as an order of magnitude, not as an exact value.

For the question of withholding food, there is no comparably strong study in dogs. The move away from it follows the evidence on how the intestinal lining is nourished and experience from human medicine and intensive care medicine – well-founded, but of a different kind than a controlled comparison.

And the recommendations on bland diets, probiotics, and the approach at the vet reflect established practice. For probiotics, the evidence is explicitly mixed; the text says so, and that is the more honest approach than a clear recommendation in one direction or the other.

16. Conclusion

Many cases of diarrhea and vomiting in dogs are mild and get better on their own – the real task is recognizing the exceptions: unproductive retching, tarry stool, weakness, and any affected puppy. What has changed are the two most widespread reflexes. Withholding food is not a way of resting the gut; it deprives the intestinal lining of a considerable part of what it feeds on. And the antibiotic shortens uncomplicated diarrhea by around a day and a half on average – at the price of gut flora that can remain altered, in part, for a longer time afterward. What actually helps is unspectacular: feed early and feed the right thing, offer water, observe, and don't wait when the warning signs mentioned above appear.

👉 What matters when choosing: What makes a good veterinarian

If you take only one thing away from this article: look at your dog, not at the stool. Whether he is eating, drinking, alert, and coming along says more about the urgency than any description of what comes out the back end.

Key takeaways on diarrhea and vomiting

Overall condition decides, not symptom severity. A dog with severe diarrhea who is eating and alert is in a different situation from a dog with mild diarrhea who withdraws.

Unproductive retching in a large dog is not a stomach upset but urgent suspicion of bloat (GDV) – and the only case in which water is withheld too.

Blanket withholding of food is outdated. The cells of the intestinal lining get a considerable part of their nourishment directly from the gut contents; prolonged fasting can weaken the barrier rather than protect it. In puppies and very small dogs, it is dangerous.

The evidence on metronidazole is mixed. In a randomized, blinded study in 31 dogs, diarrhea resolved after a median of 2.1 instead of 3.6 days (Langlois et al., 2020); in a second study in 60 dogs, there was no significant difference compared with a placebo (Shmalberg et al., 2019). Set against this is the known change in gut flora caused by metronidazole – and the cases resolved within a few days anyway.

In hemorrhagic diarrhea syndrome, adding metronidazole brought no demonstrable benefit in one study. Treatment consists primarily of intravenous fluids – the problem is not the blood lost to the outside but the loss of fluid into the intestine.

The loss of water is the real risk, not the diarrhea itself. With vomiting, offer small amounts often instead of a large bowl.

Fresh blood from the large intestine is something different from tarry stool. The former usually looks more dramatic than it is; the latter means digested blood from the upper digestive tract and should always be checked.

Undigested food coming up without effort shortly after eating is not vomiting but regurgitation – a backflow from the esophagus with causes of its own.

A fecal sample is collected over three days, because pathogens are shed intermittently – and the request has to state what is being tested for: Giardia are not worms.

References

• Langlois, D. K., Koenigshof, A. M. & Mani, R. (2020): Metronidazole treatment of acute diarrhea in dogs: A randomized double blinded placebo-controlled clinical trial. Journal of Veterinary Internal Medicine 34(1): 98–104. https://doi.org/10.1111/jvim.15664 (31 dogs; diarrhea resolved after a median of 2.1 days with metronidazole versus 3.6 days with placebo; the authors also point to considerable and partly lasting changes in the gut flora and to dietary changes and probiotics as possible alternatives)

• Rudinsky, A. J., Parker, V. J., Winston, J., Cooper, E., Mathie, T., Howard, J. P., Bremer, C. A., Yaxley, P., Marsh, A., Laxalde, J. et al. (2022): Randomized controlled trial demonstrates nutritional management is superior to metronidazole for treatment of acute colitis in dogs. Journal of the American Veterinary Medical Association 260(S3): S23–S32. https://doi.org/10.2460/javma.22.08.0349 (comparison of an easily digestible diet, diet plus metronidazole, and a fiber-enriched diet; dysbiosis index on days 0, 7, and 30)

• Shmalberg, J., Montalbano, C., Morelli, G. & Buckley, G. J. (2019): A Randomized Double Blinded Placebo-Controlled Clinical Trial of a Probiotic or Metronidazole for Acute Canine Diarrhea. Frontiers in Veterinary Science 6: 163. https://doi.org/10.3389/fvets.2019.00163 (60 dogs in three groups: 3.5 days to acceptable stool consistency with a probiotic, 4.6 days with metronidazole, 4.8 days with placebo; no statistically significant difference)

• Marks, S. L., Kook, P. H., Papich, M. G., Tolbert, M. K. & Willard, M. D. (2018): ACVIM consensus statement: Support for rational administration of gastrointestinal protectants to dogs and cats. Journal of Veterinary Internal Medicine 32(6): 1823–1840. https://doi.org/10.1111/jvim.15337 (questions the routine use of gastroprotectants without a proven indication)

Frequently asked questions about diarrhea and vomiting in dogs

The questions asked most often in the exam room