NAVLE Emergency Medicine · ⏱ 11 min read · 📅 Mar 28, 2026 · by NAVLE Exam Prep Team · 👁 1

Canine GDV (Gastric Dilatation-Volvulus): NAVLE Study Guide

GDV is the emergency that kills fast. A large-breed dog comes in with a distended abdomen and nonproductive retching — you have maybe an hour before the systemic consequences become irreversible. The NAVLE tests GDV heavily because it requires you to know pathophysiology, radiographic interpretation, treatment sequencing, and surgical decision-making all at once. Get the breed, get the radiograph, stabilize, operate. That's the sequence.

Who Gets GDV

Large and giant breeds with deep narrow chests are the classic patients. Great Danes have the highest incidence — nearly 1 in 3 will experience GDV in their lifetime. German Shepherds, Weimaraners, Standard Poodles, Irish Setters, and Dobermans round out the high-risk list. Middle-aged to older dogs are most commonly affected, though GDV can occur at any age in predisposed breeds.

Beyond breed, risk factors include once-daily large-volume feeding, eating rapidly, exercise immediately after meals, and a first-degree relative with GDV history. Body condition matters less than chest conformation — a lean deep-chested dog is still at high risk.

High-Yield The classic NAVLE vignette: a middle-aged to older Great Dane (or GSD, Weimaraner) with acute abdominal distension, nonproductive retching, and restlessness. That signalment + those three signs = GDV until proven otherwise. Great Danes approach a 1-in-3 lifetime risk — the highest of any breed.

Pathophysiology: Why It Kills So Fast

The stomach rotates clockwise 180–360 degrees (viewed from caudal, dog in dorsal recumbency). The pylorus, which normally sits ventrally on the right, swings dorsocranially to the left of midline. The spleen frequently follows, becoming entrapped and devascularized.

The distended, rotated stomach then compresses the portal vein and caudal vena cava. Venous return to the heart collapses. Cardiac output drops. Hypoperfusion leads to tissue acidosis, and acidosis further compromises cardiac function. Simultaneously, the distended stomach causes diaphragmatic compression, restricting ventilation. The spleen and gastric wall begin to necrose from ischemia. Every minute this continues, the dog moves closer to irreversible shock.

Gastric rotation
pylorus moves left
Portal vein & caudal vena cava compressed
Cardiac output collapses
Distributive shock
+ gastric necrosis

Clinical Signs

The cardinal triad is nonproductive retching, progressive abdominal distension, and restlessness. The dog cannot vomit — the cardia is obstructed — so retching produces nothing or small amounts of frothy saliva. The abdomen becomes visibly distended and tympanic on percussion, especially in the left flank. Restlessness, pacing, and hypersalivation reflect severe visceral pain.

On physical exam: tachycardia with weak thready pulses, pale or gray mucous membranes, prolonged CRT, and a tympanic abdomen. In advanced cases the dog may be recumbent and obtunded. Abdominal pain on palpation is variable — some dogs are surprisingly quiet despite severe disease.

Diagnosis: The Radiograph Decides

Take a right lateral abdominal radiograph. This is the view that reveals the compartmentalization sign. Avoid ventrodorsal positioning — a compromised dog in dorsal recumbency is at high aspiration and cardiovascular risk.

Feature Simple Gastric Dilation GDV
Pylorus position Normal (ventral right) Displaced dorsocranially, left of midline
Compartmentalization Absent Present — soft tissue band separates gas-filled compartments
Spleen Normal position May be displaced, entrapped, devascularized
Treatment required Decompression ± medical management Surgery mandatory
Classic NAVLE Trap The key radiographic finding is the malpositioned pylorus, not just stomach size. Simple dilation can look dramatic on radiographs — a massively distended stomach without compartmentalization is dilation, not GDV. The double-bubble compartmentalization sign, caused by the pylorus displacing dorsocranially, is what confirms volvulus. Do not call it GDV without that finding.

Lactate: Prognostic Tool, Not a Treatment Gate

Measure blood lactate on presentation and after initial fluid resuscitation. A lactate below 4 mmol/L is favorable. Above 6 mmol/L is concerning for gastric necrosis and higher mortality. A 50% decrease in lactate after fluid resuscitation is a positive prognostic sign.

Critical point: lactate guides prognosis but does not determine whether to operate. Surgery is always indicated in confirmed GDV regardless of lactate. A high lactate means the dog is higher risk — not that surgery should be withheld.

Treatment: Stabilize, Then Operate

Place two large-bore IV catheters in the cephalic or jugular veins — not the saphenous, which may be compromised by caudal vena cava obstruction. Run isotonic crystalloids aggressively (20 mL/kg boluses, reassess). Add colloids or hypertonic saline if shock persists. Gastric decompression via orogastric tube or trocar reduces pressure and improves venous return before surgery.

NAVLE Tip Lidocaine in GDV does double duty: it treats ventricular premature contractions (VPCs) AND provides analgesia. A lidocaine CRI at 25–50 µg/kg/min can be started preoperatively and continued intraoperatively. When the NAVLE asks about arrhythmia management in GDV, lidocaine is the answer.

Surgical Treatment

Surgery is non-negotiable. Medical decompression alone will not correct the volvulus. The surgical goals in order: decompress the stomach, derotate, assess gastric and splenic viability, resect necrotic tissue if needed, and perform gastropexy.

Gastropexy creates a permanent adhesion between the pyloric antrum and the right abdominal wall. Without it, recurrence rates are 55–80% with mortality approaching 80% on recurrence. With gastropexy, recurrence drops to less than 5%. Gastropexy is not optional — it is the definitive procedure.

One critical distinction: gastropexy prevents volvulus but not dilation. A dog with a previous gastropexy can still bloat (simple gastric dilation), but the stomach cannot rotate.

Postoperative Monitoring

Postoperative Complication Risk

Ventricular arrhythmias (VPCs)Peak 12–36 hrs, risk to 72 hrs
DICFirst 24–48 hrs
Gastric necrosis / reperfusion injuryIntraop + first 12 hrs

Cardiac arrhythmias occur in up to 70% of GDV patients. VPCs are most common. Treat with lidocaine if the dog is hemodynamically compromised or VPC frequency is high. Monitor ECG for at least 72 hours postoperatively.

Prognosis and Prevention

Overall survival with prompt treatment is 80–90%. Dogs requiring gastric resection for necrosis have 66% survival. Without gastropexy, median survival after GDV is 188 days. With gastropexy, it exceeds 547 days.

Prophylactic gastropexy is recommended for high-risk breeds at the time of spay/neuter. In Great Danes, it reduces GDV-related mortality 2–30 fold. Feeding two to three smaller meals per day, using slow-feeder bowls, and avoiding exercise for one hour after meals reduces risk but does not eliminate it.

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Practice Questions

Test yourself before moving on. Click an answer to reveal the explanation.

Question 1 An 8-year-old male Great Dane presents with a 2-hour history of nonproductive retching, progressive abdominal distension, and restlessness. Heart rate is 148 bpm with weak pulses. Right lateral abdominal radiographs show a markedly distended stomach with a soft tissue band creating two gas-filled compartments. Which radiographic finding confirms gastric volvulus rather than simple gastric dilation?

Question 2 A 6-year-old Weimaraner with confirmed GDV has a baseline blood lactate of 7.2 mmol/L. After 30 minutes of aggressive IV fluid resuscitation, repeat lactate is 5.8 mmol/L. The owner asks whether surgery should proceed given the high lactate. Which response is most appropriate?

Question 3 A 5-year-old intact female Great Dane is being spayed electively. The surgeon recommends concurrent prophylactic gastropexy. Which statement about prophylactic gastropexy is most accurate?

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