What causes gdv in dogs

Overview

Gastric Dilatation-Volvulus (GDV), often referred to as bloat or twisted stomach, is one of the most serious and rapidly progressive emergencies in veterinary medicine. It occurs in two stages: gastric dilatation (GD) and gastric volvulus (GV). GD happens when the stomach fills excessively with gas, fluid, or food, causing it to distend significantly. GV occurs when the distended stomach twists on its long axis. This twisting cuts off blood supply to the stomach and spleen, and can also impede blood return to the rest of the body, leading to shock and potentially rapid death if not treated promptly.

What Causes GDV?

The exact multifactorial cause of GDV remains somewhat elusive, but research and veterinary experience point to several contributing factors:

Breed Predisposition

Certain breeds are significantly more prone to GDV than others. This is primarily linked to their physical conformation, specifically having a deep and narrow chest. The space available for the stomach in these breeds may make it more susceptible to displacement and twisting. Commonly affected breeds include:

• Great Danes
• Weimaraners
• Standard Poodles
• Doberman Pinschers
• German Shepherds
• Saint Bernards
• Basset Hounds
• Irish Setters

While these breeds are at higher risk, GDV can occur in any dog, regardless of size or breed.

Dietary Factors

The type and way a dog eats its food can play a role. Several dietary habits have been associated with an increased risk:

• Feeding one large meal per day: Large volumes of food can increase the likelihood of gastric distension.
• Rapid eating: Dogs that gulp their food tend to swallow more air, which contributes to gastric gas accumulation.
• Diet composition: While evidence is mixed, some studies suggest that diets high in fat or containing large amounts of fermentable ingredients (like soy-based proteins) might increase risk. Dry kibble diets, especially those that expand significantly when wet, have also been implicated, though this is debated.
• Sudden diet changes: Abruptly switching food can upset a dog's digestive system and potentially contribute to GDV.

Eating Habits and Environment

Beyond what they eat, how and when a dog eats can be important:

• Stress and anxiety: Dogs that are stressed or anxious may eat more quickly or exhibit behaviors that could predispose them to GDV.
• Eating from raised bowls: Contrary to previous beliefs, studies have shown that feeding from raised feeders may actually increase the risk of GDV in some dogs, particularly larger breeds. The mechanism is not fully understood but may relate to altered posture or increased air swallowing.
• Drinking large amounts of water quickly: Similar to eating quickly, gulping large volumes of water can contribute to stomach distension.

Genetics and Physiology

There appears to be a genetic component to GDV susceptibility. Dogs with a family history of GDV are at a higher risk. The physiological state of the stomach, including its motility and the tone of the esophageal sphincter, can also influence its tendency to dilate and twist.

Other Potential Factors

While less definitively proven, other factors sometimes discussed include:

• Age: Older dogs may be at a slightly increased risk.
• Previous abdominal surgery.

What Happens During GDV?

The process typically begins with gastric dilatation. Gas builds up in the stomach due to fermentation of food, swallowing air, or improper eructation (belching). As the stomach expands, it can put pressure on surrounding organs and the diaphragm, making breathing difficult. If the stomach then rotates (volvulus), the pylorus (lower part of the stomach) moves to the left and dorsally, while the greater curvature moves to the right and ventrally. This twisting obstructs the esophagus, preventing the dog from vomiting or belching to relieve pressure. It also constricts the blood vessels supplying the stomach and spleen, leading to tissue damage, necrosis (death of tissue), and potentially rupture. The spleen can also become torqued, compromising its blood supply.

Recognizing the Signs and Seeking Help

GDV is a surgical emergency. Immediate veterinary intervention is crucial for survival. Signs to watch for include:

• Restlessness and pacing
• Distended or hard abdomen
• Unproductive retching (trying to vomit but nothing comes up)
• Excessive drooling
• Gagging
• Rapid breathing or panting
• Weakness
• Pale gums
• Collapse

If you suspect your dog has GDV, contact your veterinarian or an emergency animal hospital immediately. Time is of the essence.

Prevention and Risk Reduction

While GDV cannot be entirely prevented, owners can take steps to reduce the risk:

• Feed multiple small meals per day rather than one large one.
• Encourage slower eating by using slow-feeder bowls or puzzle toys.
• Avoid strenuous exercise for at least one hour before and after meals.
• Avoid feeding from raised bowls, especially for at-risk breeds.
• If switching foods, do so gradually over a week.
• Consult your veterinarian about diet recommendations.
• For dogs at very high risk (e.g., deep-chested breeds with a history of GDV or bloat), prophylactic gastropexy (a surgical procedure to tack the stomach in place) may be recommended by your vet.

Understanding the risk factors and recognizing the signs of GDV can significantly improve a dog's chances of survival.