Acid Reflux (GERD) in Dogs: Signs, 8 Common Causes, What Makes It Worse, and How Diet Can Calm It

Expert Advice

8 Sept

“Is your dog showing signs of acid reflux? Discover the top causes of canine GERD, symptoms to watch for, what makes reflux worse, and how a low-fat, reflux-friendly diet can help. Learn why fat under 12% dry matter is key, with science-backed tips and peer-reviewed studies.”

What is reflux in dogs?

Reflux happens when the lower oesophageal sphincter (LES) fails to keep acidic stomach contents where they belong. The acid and enzymes irritate the lining of the oesophagus, causing oesophagitis. In dogs, you won’t hear “heartburn” complaints—but you’ll see behaviour and feeding changes. Endoscopy is the gold-standard diagnostic tool, and treatment typically combines acid suppression, oesophageal protection, prokinetics, and dietary change. Merck Veterinary Manual

Signs & subtle clues of reflux

Dogs don’t describe heartburn—so watch for:

Regurgitation (often soon after eating; passive, no heaving)
Lip-licking, gulping, repeated swallowing
Hyporexia (reduced appetite), dysphagia (difficulty swallowing)
Ptyalism (drooling), change in bark, chronic cough
Restlessness at night, neck extension during episodes
In severe cases: weight loss or food aversion

These signs overlap with other issues (foreign body, oesophageal stricture, megaoesophagus), so veterinary assessment is essential. Merck Veterinary Manual Vca MSD Veterinary Manual

The top 8 reasons dogs get reflux

Reflux is usually multifactorial. For many dogs, two or more of the reasons below are in play.

Hiatal hernia & brachycephalic airway syndrome (BOAS)
Short-nosed breeds (French Bulldog, Bulldog, Pug, Boston Terrier, etc.) are over-represented for hiatal hernia and reflux. Negative intrathoracic pressure from airway obstruction can draw gastric contents upward. Studies document a higher-than-expected prevalence of hiatal hernia and reflux in brachycephalics. PubMed PMC Taylor & Francis Online
Anaesthesia & sedation
Under general anaesthesia, GER is common: reports range from ~44% to 88% of dogs experiencing at least one reflux episode intra-op, influenced by protocol and fasting intervals. PMC+1
Drugs that relax the LES
Certain medicines (e.g., atropine, acepromazine) reduce LES tone and are linked with reflux and oesophagitis. Merck Veterinary Manual
Gastritis, chronic vomiting, or primary oesophagitis
Inflammation and repeated emesis disturb normal motility and irritate the oesophagus, perpetuating reflux. Endoscopy confirms severity and guides therapy. Merck Veterinary Manual
Delayed gastric emptying (e.g., functional dysmotility; pyloric disease)
When the stomach empties slowly, volume and pressure increase—promoting reflux. High-fat meals are a classic dietary trigger because they markedly delay gastric emptying in dogs (see Section “Why fat matters”). PubMed
Brachycephalic conformation without a formal hernia
Even without a confirmed hernia, BOAS dogs demonstrate increased reflux/regurgitation on pH or videofluoroscopic studies, likely due to airway-related pressure changes. PMC Wiley Online Library
Strictures or post-injury changes
Caustic ingestion, chronic reflux, or foreign bodies can scar the oesophagus, narrowing the lumen and worsening regurgitation—creating a vicious circle. MSD Veterinary Manual
Feeding pattern & portions
Large, infrequent meals increase gastric volume and transient relaxations of the LES; small, frequent meals are a core management tool for canine oesophagitis. Merck Veterinary Manual

What makes reflux worse?

High-fat meals or treats (skin, fatty minced meats, cheese, creamy toppers, coconut products, generous fish-oil dosing): fat slows gastric emptying in dogs and raises the odds of refluxing contents lingering in the stomach. PubMed
Bulky, high-fibre meals during a flare: fibre can delay gastric emptying and is not first-line during active oesophagitis (the Merck Vet Manual advises soft, low-fat, low-fibre feeding in small, frequent meals). Merck Veterinary Manual
Very large portions or late-night feeding (more volume + recumbency = easier reflux). Practical tip: Finish the last meal 3–4 hours before bed (clinical common sense; align with small/frequent feedings). Merck Veterinary Manual
Strenuous exercise soon after eating (increases abdominal pressure; empirical clinical guidance—schedule activity away from meals).
Collars that increase cervical/oesophageal pressure in symptomatic dogs—prefer a well-fitted harness during flare-ups (best-practice handling).
Anaesthesia (unavoidable sometimes, but speak with your vet about reflux-aware protocols and fasting intervals). Studies show protocol and fasting duration affect intra-operative GER risk. AVMA Journals

Diagnosis: how vets figure it out

History + physical exam to distinguish regurgitation vs vomiting and to spot red flags (aspiration risk, weight loss).
Baseline tests (CBC/biochemistry/urinalysis) to rule out systemic disease; imaging (thoracic radiographs, ultrasound) to exclude masses or secondary issues.
Endoscopy to visualise oesophagitis, rule out foreign bodies, and obtain biopsies if needed.
Videofluoroscopic swallow studies and/or pH/impedance monitoring for brachycephalic or complex cases to objectively document reflux/regurgitation. Merck Veterinary Manual PMC

Treatment overview (briefly)

Your vet may consider:

Acid suppression: PPIs (e.g., omeprazole, esomeprazole) are often preferred in moderate–severe oesophagitis; H₂-blockers (famotidine) for mild disease or as adjuncts. PubMed
Oesophageal protectants: Sucralfate slurry to coat and protect damaged mucosa. Merck Veterinary Manual
Prokinetics: To improve motility and increase LES tone—cisapride shows the most consistent effect on LES pressure in dogs; metoclopramide’s effects are less reliable. PubMed AVMA Journals ScienceDirect
Treat underlying causes: BOAS surgery/management, treat gastritis/IBD, address strictures (balloon dilatation), manage hernias where indicated. MSD Veterinary Manual

Diet and feeding strategy are always part of the plan—often the part you control most day-to-day.

Diet & feeding strategy: what actually helps

1) Why fat matters (the canine data)

In a controlled canine study, adding corn oil (a high-fat load) significantly prolonged gastric emptying and total transit time; many capsules were retained in the stomach after fatty feeding. Slower emptying = more time and pressure for reflux to happen. That’s why most reflux-friendly diets keep fat moderate to low. PubMed

Target during a flare:

≤12% fat DM is a sensible ceiling for most dogs with active reflux/oesophagitis. Many do best below ~10% DM initially, then titrate up as signs settle (individualise with your vet).

Merck guidance aligns: soft food, low in fat and fibre, fed in small, frequent meals. Merck Veterinary Manual

2) Protein: keep it moderate and gentle

Protein is essential for healing, but very high-protein meals can stimulate gastric acid production (physiology), and dense meaty meals can be rich in fat by default. In practice, choose lean proteins and avoid extreme protein loads during a flare. (Direct dog-specific evidence is limited; clinical guidance emphasises fat reduction and easy digestibility.) Merck Veterinary Manual

3) Carbohydrate & fibre

Opt for easily digestible carbs (well-cooked rice, potato/sweet potato without added fats). During active oesophagitis, keep fibre low to moderate; build back variety later. Merck Veterinary Manual

4) Texture & temperature

Soft or blended meals reduce oesophageal work and are better tolerated mid-flare. Serve lukewarm (not hot/cold).

5) Meal pattern

Feed 3–6 small meals/day. Last meal 3–4 hours before bedtime ( this is different if dogs are nauseous in the morning, they can benefit from a late snack); keep post-meal activity gentle. Merck Veterinary Manual

6) Practical “eat this / avoid this” during a flare

Choose (examples):

Proteins: poached skinless turkey or chicken breast, white fish (cod/haddock/pollock), extra-lean minced beef (5% fat or less), low-fat cottage cheese/yoghurt if tolerated.
Carbs: well-cooked white rice, mashed potato/sweet potato (no butter/oil), plain pasta.
Extras: small amounts of pumpkin purée for stool consistency (if needed), broths defatted and low-salt.

Avoid/limit:

Oily fish, fattier cuts (lamb, duck, pork belly), skin, gravy, cheese toppers, butter, coconut oil, rich treats, training treats with high fat, and large bones or very chewy hides during active oesophagitis.

If your dog needs therapeutic nutrition (e.g., GI low-fat veterinary diets), use under veterinary guidance and monitor weight and stool quality.

How to check fat on a dry-matter basis (DMB)

Dry-matter comparison removes the “water factor” so you can compare wet vs dry fairly.

Rule of thumb / quick math:

100 − moisture % = dry matter % of the food
(Nutrient % “as fed”) ÷ (dry matter %) × 100 = nutrient % on a DMB

Example: A wet food shows 4% fat, 78% moisture.
Dry matter = 100 − 78 = 22.
Fat DM% = 4 ÷ 22 × 100 = 18.2% DM (not “low fat” despite the label looking tiny).

Want a ready-made tool? Use Tufts’ calculator:
https://sites.tufts.edu/petfoodology/2017/08/07/nutrient_converter/ Tufts Self-Serve Blogs and Websites

Target: For reflux-prone dogs, look for ≤12% fat DM (often 8–10% during flares), then adjust to your dog’s response and overall calorie needs. (Pair DM checks with sensible kcal/100g so you don’t unintentionally overfeed fat-dense foods.) Merck Veterinary Manual

Brachycephalic dogs: special notes

BOAS dogs frequently show reflux/regurgitation on objective testing, and hiatal hernia is more common than many owners realise—especially in French Bulldogs. Management often blends airway optimisation, reflux-friendly feeding, and, when indicated, surgical correction of hernia or airway abnormalities. PubMed PMC

Frequently asked questions

Can probiotics or alginates help?
They’re not core therapies for oesophagitis, but some dogs benefit from broad-spectrum probiotics as gut support during diet changes. Alginate products (human antacids) sometimes feature in plans, but only under veterinary guidance to avoid interactions with other meds.

Should I raise the bowl?
If regurgitation is prominent, a modest elevation can help some dogs; avoid extreme heights and always prioritise small meals and calm post-meal routines. (Evidence is limited; base on your vet’s advice and your dog’s response.)

How long should a low-fat plan last?
Typically through the healing phase (weeks), then re-challenge gradually to find each dog’s tolerance “ceiling”—while maintaining good control of signs.

A step-by-step nutrition game-plan

Stabilise the flare (2–4 weeks):
- Fat ≤10–12% DM, low fibre, soft texture, 3–6 small meals/day.
- Choose lean proteins + simple carbs; avoid rich treats and table scraps. Merck Veterinary Manual
Re-assess signs weekly:
- Watch for decreased gulping, less lip-licking, improved appetite, fewer regurgitation episodes. Keep a food/symptom diary.
- Look at weight gain if weight loss was apparent
Build back variety cautiously:
- Trial slightly higher-fat proteins (e.g., salmon) later, one at a time, and only if symptoms are quiet.
Address weight and pacing:
- Slight weight reduction can reduce abdominal pressure and reflux in overweight dogs.
- Space meals and exercise (gentle activity is fine; avoid vigorous play soon after meals).
For brachycephalics:
- Ask your vet about BOAS assessment; in some dogs, airway therapy reduces reflux frequency and improves quality of life. PMC

Sample day (home-prepared during a flare)

(For a 20–25 kg moderately active adult; adjust total calories to your dog’s needs. This is a conceptual example, not a complete & balanced long-term diet.)

Breakfast: Poached skinless turkey breast + well-cooked white rice mashed with a little defatted broth → blenderise to a soft mash.
Mid-morning: Small portion of the same mash.
Lunch: White fish (cod) gently steamed + mashed potato; dilute with warm water to porridge-like texture.
Mid-afternoon: Small top-up portion.
Dinner (early): Turkey-rice mash again; finish 3–4 h before sleep.
Avoid: oils/butters, rich treats, crunchy chews during healing.

For complete and balanced long-term home-cooked plans (with supplements to FEDIAF/NRC) you can book a consult with me online here

The science behind the key recommendations (selected evidence)

What oesophagitis is, how we diagnose and feed it: Merck Vet Manual (professional version) recommends soft food, low in fat and fibre, small frequent meals; outlines endoscopy as the diagnostic tool of choice and lists drugs that reduce LES tone. Merck Veterinary Manual
Signs and practical overview for owners: VCA overview of canine GERD covers clinical signs, endoscopy, and notes diet (often low-fat) plus small, frequent meals. Vca
Fat slows gastric emptying in dogs: In a canine pilot study, fat loading (corn oil) significantly increased gastric emptying time and retained test capsules, supporting low-fat feeding during reflux. PubMed
High anaesthesia-time GER: Studies show 44–88% of dogs experience at least one GER episode under anaesthesia, highlighting the importance of protocol and fasting strategy. PMC+1
Brachycephalics & reflux: French Bulldogs and other BOAS breeds show increased prevalence of hiatal hernia and documented reflux/regurgitation on objective testing. PubMed PMC
Acid suppressants & prokinetics: ACVIM consensus supports rational PPI/H₂RA use; cisapride has the clearest evidence for increasing LES pressure in dogs. PubMed+1 AVMA Journals

References - peer-reviewed

Merck Veterinary Manual — Esophagitis in Small Animals (revised 2022; modified 2024). Recommends low-fat, low-fibre, soft diets in small frequent meals; details diagnosis and drugs impacting LES tone. Merck Veterinary Manual
ACVIM Consensus Statement (2018) — Rational administration of GI protectants to dogs and cats. J Vet Intern Med. Guidance on PPI/H₂RA use. PubMed
Palerme JS et al. (2020) — Effect of fat loading on gastrointestinal transit in dogs. Demonstrates fat-induced delays in gastric emptying. PubMed
Lambertini C et al. (2020) — Incidence of gastro-oesophageal reflux during anaesthesia in dogs. High intra-op GER incidence. PMC
Flouraki ES et al. (2022) — Premedication and reflux incidence during anaesthesia. Reports ~44% GER across protocols. PMC
Reeve EJ et al. (2017) — Prevalence of hiatal hernia in French Bulldogs. Higher-than-expected rates; oesophageal disease common. PubMed
Appelgrein C et al. (2022) — Quantification of GER in brachycephalics using pH probe. Documents reflux/regurgitation burden. PMC
Kempf J et al. (2014) & Ullal TV et al. (2016) — Canine manometry studies: cisapride increases LES pressure; metoclopramide less consistent. PubMed AVMA Journals
VCA Animal Hospitals — Owner-facing overview of GERD signs, diagnosis, and diet. Vca
Tufts Petfoodology — Nutrient converter for dry-matter & per-100 kcal comparisons. https://sites.tufts.edu/petfoodology/2017/08/07/nutrient_converter/ Tufts Self-Serve Blogs and Websites

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