If your dog has a swollen belly, keeps retching but brings nothing up, drools heavily and cannot settle, treat it as a life-threatening emergency and drive to the nearest emergency veterinary hospital immediately. Bloat in dogs usually means gastric dilatation-volvulus (GDV), where the stomach fills with gas and can twist, and it can be fatal within hours without treatment. Phone the clinic on the way, and do not wait to see whether it passes, including overnight.
Below is a five-minute action list, a symptom table, an explanation of why owners cannot tell simple bloat from a twisted stomach, and what Australian studies and international research say about risk, survival and prevention, including where the evidence disagrees.
What to do in the first five minutes
This list follows the Merck Veterinary Manual‘s advice to seek immediate veterinary care when signs are apparent. The travel details are common-sense emergency practice, not trial findings.
- Phone your vet or the nearest 24-hour emergency hospital now and say “I think my dog may have bloat or GDV.” If your regular clinic is closed, use the after-hours message or the emergency hospital.
- Leave straight away. If someone else can drive, they drive and you keep the dog calm. Do not stop to search for information.
- Do not give food. Ask the clinic by phone before offering water or anything else. The veterinary sources reviewed give no owner first-aid steps beyond getting the dog to a clinic.
- Do not make the dog vomit, press or massage the belly, walk the dog to “settle it”, or give any medicine (anti-gas products, anti-nausea tablets, painkillers) unless the vet tells you to.
- Tell the clinic when the dog last ate or drank, when signs started, the breed and weight, any past surgery (especially spleen removal) and any medication.
Bloat in dogs: symptoms to look for
Signs can start suddenly. The stomach can trap gas without obvious swelling early on, so a normal-looking belly does not rule bloat out. The table combines signs from the Merck Veterinary Manual (professional version, full review August 2025) and PetMD (updated February 2024).
| Stage | What you may notice | Comment |
|---|---|---|
| Early | Unproductive retching (trying to vomit, little or nothing comes up), sometimes white foam | Merck lists “nonproductive retching” among early signs. |
| Early | Heavy drooling | Merck: hypersalivation. |
| Early | Restlessness, pacing, unable to settle | Often looks like anxiety. |
| Early to advanced | Swollen or tight belly | Merck says distension “may be noted”. PetMD notes swelling may not be visible early. |
| Early to advanced | Belly pain: whining, a hunched or “praying” stance | Do not press the belly to check. |
| Advanced | Fast, shallow breathing or panting not explained by heat or exercise | Merck: the swollen stomach can compress the chest. |
| Advanced (shock) | Pale gums, weak pulse, fast heart rate, weakness, collapse | A critical stage (Merck). |
Merck lists clinical signs lasting more than 6 hours before examination among the factors linked to short-term death.
Bloat or GDV: why you cannot tell at home
In gastric dilatation (GD) the stomach is stretched with gas and fluid. In GDV it has also rotated, which traps the gas, can cut off blood flow and can cause shock. According to Merck, X-rays distinguish them.
| Gastric dilatation (GD) | Gastric dilatation-volvulus (GDV) | |
|---|---|---|
| What is happening | Stomach stretched by gas and fluid | Stretched stomach has also rotated |
| Can an owner tell them apart? | No. Signs overlap. Diagnosis needs a vet, usually with X-rays. | |
| Can a vet always tell quickly? | Usually, but not always. A 2025 German case report describes a 360-degree twist that was hard to separate from simple dilatation on first X-rays. It is a single case. | |
| Safe plan for the owner | Treat every suspected case as GDV and go to the emergency hospital. | |
Some websites say mild signs can be watched for a while. We found no veterinary study supporting that, and the veterinary sources reviewed advise urgent care whenever bloat is suspected.
What Australian studies show about survival and timing
Two Australian studies are useful because they come from emergency and referral hospitals.
| Study | Population | Findings |
|---|---|---|
| Song et al., Aust Vet J 2020 (PMID 32253749) | 736 confirmed GDV cases at two Sydney referral and emergency centres, 1999 to 2019 | 460 dogs had surgery and 276 were humanely killed. Survival after surgery was 81.7% when operated on by general surgeons and 88.7% by specialists. Mortality odds were 2.53 times higher when more than 3 hours passed between presentation and the end of surgery, and 3.57 times higher for dogs presenting between 3 am and 9 am than between 9 am and 9 pm. The study cannot say why. |
| Anderson et al., N Z Vet J 2021 (PMID 33896404) | 147 non-referred GDV cases at a Melbourne university hospital emergency department, 2008 to 2017 | Insurance status was known for 69 dogs: 10 insured, 59 not. 37 of 59 uninsured dogs (63%) were euthanised before surgery; none of the 10 insured dogs were. Of 32 dogs that had surgery, 4 did not survive to discharge. The estimate is imprecise because few dogs were insured. |
Two practical points follow. First, in these hospitals most dogs that reached surgery survived, and delay was linked to worse outcomes. Leaving it until morning is not supported by the evidence. Second, many deaths in GDV datasets are decisions made before surgery, and cost is part of that. If cost worries you, tell the emergency clinic on the phone and ask what options exist, but do not delay the journey to decide.
| Source | Figure | What was counted |
|---|---|---|
| O’Neill 2017 (UK, PMID 28833166) | 49.7% of dogs presented alive survived to discharge; 79.3% of surgical cases | UK emergency practices; about half of owners chose surgery. |
| Sharp 2020 (US, PMID 32077192) | 64.1% of 498 dogs survived; 83.5% when dogs euthanised before surgery were excluded | 116 dogs were euthanised on arrival without surgery. |
| Glickman 2000 (US, PMID 10638316) | 28.6% (30 of 105) died | Prospective cohort of large and giant breeds. |
| Merck (Aug 2025) | 20%, 20 to 45% and 25 to 30% in treated animals | Different figures appear in different sections of the page. |
Which dogs are most at risk?
We did not find breed-level incidence data for Australian dogs in the sources reviewed, so the breed figures below are from the UK and US and are labelled as such. GDV mainly affects large and giant, deep-chested dogs.
| Study | Population | What it found |
|---|---|---|
| O’Neill 2017 (UK) | 77,088 dogs at 50 emergency clinics | 492 (0.64%) had presumptive GDV. Compared with crossbreeds, odds were 114.3 times higher for Great Danes, 84.4 for Akitas and 82.9 for Dogues de Bordeaux. Odds rose with age up to 12 years. Emergency population, so it overstates risk across all dogs. |
| Glickman 2000 (US) | 1,914 dogs of 11 large and giant breeds | 23 to 26 cases per 1,000 dog-years in large (23 to 45 kg) and giant (over 45 kg) breeds. Cumulative incidence 5.7%. |
| McCord 2026 (US, PMID 41349220) | 47,444 dogs, 170 owner-reported cases | Higher odds in purebreds, males, dogs over 40 kg, thin dogs, and Poodles and Poodle mixes. |
Risk factors: what is supported and what conflicts
| Factor | What the studies found | Evidence strength and caveats |
|---|---|---|
| Large or giant, deep-chested breed | Consistent in UK and US data. | Strong. |
| Increasing age | Higher risk with age (Glickman 2000; O’Neill 2017). | Consistent. |
| Close relative with GDV | Higher risk (Glickman 2000, PMID 11128539); Merck calls genetics a “proven risk factor”. | Strong. |
| Previous splenectomy | Odds 5.3 times higher (Sartor 2013, PMID 23634682; interval 1.1 to 26.8). | Moderate; wide uncertainty. |
| Male | Higher in Glickman 1997 (PMID 9138229) and McCord 2026. Merck reports no sex predisposition. | Conflicting. |
| Thin or underweight | Higher risk in Glickman 1997 and McCord 2026. | Moderate. |
| Eating fast; large volume per meal | Higher risk (Glickman 1997 and 2000; Raghavan 2004, PMID 15131099). | Moderate; owner-reported. |
| One meal a day | Higher in Glickman 1997. McCord 2026 found no link with meals per day. | Conflicting. |
| Raised food bowl | Glickman 2000 attributed about 20% (large) and 52% (giant) of cases to a raised bowl. Merck advises avoiding elevated bowls. | Weak to moderate; one cohort, not replicated in the sources reviewed. |
| Fat or oil among first four ingredients of dry food | 2.4-fold higher risk in 85 cases (Raghavan 2006, PMID 16397192); McCord 2026 found no link with diet type. | Weak and unconfirmed. |
| Exercise soon after eating | Advised against by Merck. We found no controlled study testing it. | Expert advice only. |
Size, breed, age and family history are the factors you can trust. Feeding rules are sensible and low-risk but unproven, and none removes the risk or justifies waiting if signs appear.
What happens at the hospital
Merck describes the immediate goals as restoring blood volume and decompressing the stomach, using IV fluids, oxygen and a stomach tube or needle. Surgery repositions the stomach, checks for dead tissue and usually includes a gastropexy, which stitches the stomach to the body wall. Decompression without surgery has an “extremely high recurrence rate”.
Preventive gastropexy
Merck says a gastropexy “has not been shown to prevent bloat (gastric dilation)” but “should prevent the life-threatening volvulus”. The evidence is retrospective: in 61 dogs followed for a median of 717 days, none developed GDV after incisional gastropexy, although 3 of 27 preventive cases (11.1%) had recurrent dilatation alone (Benitez 2013, PMID 23535748); and among 766 dogs, direct complications at the gastropexy site occurred in 3 (0.4%), though only 61 procedures were elective (de la Vega 2023, PMID 37908004). We found no randomised trial. It is surgery, so discuss breed risk, family history, age and cost with your vet.
Myths and facts
| Claim | Verdict |
|---|---|
| “A dog with bloat will always vomit.” | No. The classic sign is retching with little or nothing coming up. |
| “No swollen belly, so it isn’t bloat.” | Not safe to assume. Swelling may not be visible early. |
| “I can treat it at home.” | No. PetMD states there are no home remedies, and treatment in Merck is hospital-based. |
| “It is always fatal.” | No. In Song 2020, survival after surgery was 81.7% to 88.7%. It is fatal without treatment. |
| “I’ll wait until the vet opens.” | Not supported. Longer delays to surgery were linked to higher mortality. |
| “A raised bowl prevents bloat.” | Not supported. The one study that tested it linked raised bowls to higher risk. |
If your dog is at higher risk: a checklist for today
- Save your vet’s after-hours details and the address of your nearest 24-hour emergency hospital in your phone, especially if you live far from one.
- Ask your vet whether your dog’s breed and family history justify a preventive gastropexy.
- Use low-risk routines: smaller portions, a slower pace for fast eaters, a quiet rest after meals.
- Tell any vet if your dog has had its spleen removed.
Frequently asked questions
What are the first signs of bloat in a dog?
Unproductive retching, heavy drooling and restlessness, sometimes with a swollen belly. Early swelling may not show, so phone an emergency vet straight away.
How fast can bloat kill a dog?
There is no fixed time. Merck links signs lasting more than 6 hours before examination with higher short-term death risk. Treat every suspected case as an emergency.
Can I wait until morning?
No source supports waiting. In Song 2020, longer time from presentation to completed surgery and presentation between 3 am and 9 am were both linked to higher mortality, though the study cannot say why.
Can I tell bloat from GDV myself?
No. Diagnosis needs a vet and usually X-rays. Treat every suspected case as GDV.
What should I not do?
Do not induce vomiting, press the belly, give food or medicine, or delay the journey.
Does pet insurance matter for bloat?
One Melbourne study found uninsured dogs about five times more likely to be euthanised before surgery, but few dogs were insured, so treat the estimate as imprecise. If cost worries you, discuss options with the clinic on the phone.
Sources
- Merck Veterinary Manual (professional version). Gastric Dilation and Volvulus in Small Animals. Winkler KP; peer reviewed by Carnevale J. Full review August 2025. merckvetmanual.com
- PetMD. Bloat in Dogs. Updated February 29, 2024. petmd.com
- Song KK, Goldsmid SE, Lee J, Simpson DJ. Retrospective analysis of 736 cases of canine gastric dilatation volvulus. Aust Vet J. 2020;98(6):232-238. PMID 32253749. DOI 10.1111/avj.12942.
- Anderson S, Stevenson MA, Boller M. Pet health insurance reduces the likelihood of pre-surgical euthanasia of dogs with gastric dilatation-volvulus in the emergency room of an Australian referral hospital. N Z Vet J. 2021;69(5):267-273. PMID 33896404. DOI 10.1080/00480169.2021.1920512.
- O’Neill DG, Case J, Boag AK, et al. Gastric dilation-volvulus in dogs attending UK emergency-care veterinary practices: prevalence, risk factors and survival. J Small Anim Pract. 2017;58(11):629-638. PMID 28833166. DOI 10.1111/jsap.12723.
- Glickman LT, Glickman NW, Schellenberg DB, Raghavan M, Lee TL. Incidence of and breed-related risk factors for gastric dilatation-volvulus in dogs. J Am Vet Med Assoc. 2000;216(1):40-45. PMID 10638316. DOI 10.2460/javma.2000.216.40.
- Glickman LT, Glickman NW, Schellenberg DB, Raghavan M, Lee T. Non-dietary risk factors for gastric dilatation-volvulus in large and giant breed dogs. J Am Vet Med Assoc. 2000;217(10):1492-1499. PMID 11128539. DOI 10.2460/javma.2000.217.1492.
- Glickman LT, Glickman NW, Schellenberg DB, Simpson K, Lantz GC. Multiple risk factors for the gastric dilatation-volvulus syndrome in dogs: a practitioner/owner case-control study. J Am Anim Hosp Assoc. 1997;33(3):197-204. PMID 9138229. DOI 10.5326/15473317-33-3-197.
- Raghavan M, Glickman N, McCabe G, Lantz G, Glickman LT. Diet-related risk factors for gastric dilatation-volvulus in dogs of high-risk breeds. J Am Anim Hosp Assoc. 2004;40(3):192-203. PMID 15131099. DOI 10.5326/0400192.
- Raghavan M, Glickman NW, Glickman LT. The effect of ingredients in dry dog foods on the risk of gastric dilatation-volvulus in dogs. J Am Anim Hosp Assoc. 2006;42(1):28-36. PMID 16397192. DOI 10.5326/0420028.
- McCord MA, O’Brien J, Ryave J, et al. Gastric dilatation-volvulus is associated with Poodle breeds, increased body size, and male sex, but not primary diet type or anxiety in the Dog Aging Project cohort. J Am Vet Med Assoc. 2026;264(4). PMID 41349220. DOI 10.2460/javma.25.09.0609.
- Sharp CR, Rozanski EA, Finn E, Borrego EJ. The pattern of mortality in dogs with gastric dilatation and volvulus. J Vet Emerg Crit Care. 2020;30(2):232-238. PMID 32077192. DOI 10.1111/vec.12932.
- Sartor AJ, Bentley AM, Brown DC. Association between previous splenectomy and gastric dilatation-volvulus in dogs: 453 cases (2004-2009). J Am Vet Med Assoc. 2013;242(10):1381-1384. PMID 23634682. DOI 10.2460/javma.242.10.1381.
- Benitez ME, Schmiedt CW, Radlinsky MG, Cornell KK. Efficacy of incisional gastropexy for prevention of GDV in dogs. J Am Anim Hosp Assoc. 2013;49(3):185-189. PMID 23535748. DOI 10.5326/JAAHA-MS-5849.
- de la Vega M, Ralphs SC. Outcomes and complications of prophylactic incisional gastropexy in 766 dogs (2009-2019). BMC Res Notes. 2023;16(1):300. PMID 37908004. DOI 10.1186/s13104-023-06595-6.
- Lang A, Bohme S, Kuhn V, Rayher S, Lautersack O. Diagnostic challenges of a 360 degree gastric dilatation volvulus in a dog: a case report [German]. Tierarztl Prax Ausg K Kleintiere Heimtiere. 2025;53(3):167-172. PMID 40513607. DOI 10.1055/a-2589-3449.
This article is general information, not veterinary advice, and cannot diagnose your dog. If your dog shows any sign described here, contact an emergency vet immediately.