57 Stomach in Knots? What Could Go Wrong?

GOAL

• To understand what Gastric Dilatation Volvulus (GDV) is and its effects in dogs.

LEARNING OBJECTIVES

• What is GDV?
• What causes GDV?
• What are the clinical signs of GDV?
• What are the effects of GDV?

REVIEW MATERIAL

OVERVIEW OF THE ANATOMY

Food moves into the stomach from the esophagus via the opening of the cardiac sphincter. Food then moves through the various parts of the stomach (cardiac, fundus, body, and pylorus) and into the small intestines via the pyloric sphincter.  The main portal vein has branches that come off it that go to both the spleen and the stomach. This gives blood flow to both the stomach and spleen. The caudal vena cava coming from the heart also runs right along the stomach. To the left side of the stomach, the spleen will be found.

Think about what could happen to these various structures if the stomach was twisted. 

WHAT IS GDV?

GDV is gastric dilatation and volvulus. Gastric dilatation is also known as bloat. Bloat occurs when there is gas, fluid, or ingesta build up into the walls of the stomach leading to extreme pressure within the stomach itself causing a distended or swollen look to an animal’s belly. They look as if they are bloated just like we sometimes do after eating a large meal. The extra pressure within the stomach leads to poor circulation of the stomach. With GDV, increased pressure will lead to the rotation or twisting of the entire stomach. You can think of it as the stomach is twisting and tying itself into a knot. The esophagus will twist as the pylorus part of the stomach moves upward. The pylorus ends up on the opposite side of the stomach trapping the air, fluid, or ingesta inside. This tying will cause constriction (or cutting off circulation) of the vessels to and around the stomach.

Watch this video below to see what happens:

WHAT CAUSES GDV?

The exact cause of this is not completely known. It is found to be associated with a large intake of food or water and potential increased stress of the animal. It is more common in large, deep-chested breeds of dogs.

Feed management is the best way to control this including:

• Feeding 2-3 smaller meals a day rather than one large meal
• Avoiding of feeding foods with oil as one of the first four ingredients
• Using a slow feeder bowl, puzzles, toys to help control the rate at which your dog eats the feed
• Avoiding of high exercise after a meal

WHAT ARE THE CLINICAL SIGNS OF GDV?

• Belly pain/discomfort
• Drooling
• Act of retching without vomiting
• Bloated/distended appearance
• More severe signs: blue gums, tachycardia, weakness, systemic shock

WHAT ARE THE EFFECTS OF GDV?

Within the GI tract:

The rotation and expansion of the stomach can cause many issues within the GI tract. One of the main complications that occurs is cell death and sloughing of the gastrointestinal tract, stomach and spleen. This is caused by a lack of blood flow due to the rotation and expansion of the stomach that puts pressure on the large arteries/veins within the area. As the stomach dies from a lack of blood flow, toxins are released into the blood and the shock worsens. The stomach can eventually rupture if swelling continues.

Additional systemic effects:

In addition to cutting off blood flow to the GI organs, the swelling of the stomach increases pressure on the large veins/arteries housed within the abdomen (ie. aorta, vena cava, etc). This causes circulation to slow throughout the body leading to a state of septic shock and vital organ death due to the lack of blood and oxygen. The swelling of the stomach, along with the lack of blood flow can also cause the dog to collapse with respiratory issues and cardiac arrhythmias often present.

ACTIVITY – CASE STUDIES

Think, Pair, Share

• Think: Have each student think about the individual cases on their own for 5-10 minutes
• Pair: Have the students pair up or in a group of 3-4 students to discuss what they originally thought about the case for another 5-10 minutes
• Share: Have a group discussion as a class for each case

Case #1:

Jet, a 5 month old male intact Bernese Mountain Dog presented with a 2 hour history of unproductive retching and abdominal distention. He had no history of this disease before and was up to date on his vaccinations.

On physical exam: BAR ( bright, alert, and responsive) and was unremarkable except that he had increased saliva output and some abdominal dilation.

Vitals: normal body temperature, increased respiratory rate, increased heart rate, increased capillary refill time.

Radiograph of abdomen:

Findings: Reversed C shaped stomach, enlarged stomach, gas and ingesta filled

Treatment: Jet underwent abdominal surgery to correct the twisting of his stomach. It was found that his stomach had rotated 270 degrees and both the right and left gastric vessels were torn leading to blood within the abdomen. This blood was aspirated and correction of the stomach was complete. Jet recovered with no surgical complications and was back to his normal self in no time!

Questions:

-After reviewing the case, what are your initial thoughts?

– What aspect of the history would make you suspect GDV?

– What clinical signs did you notice in Jet that could have led you to know that he had GDV?

Reference: Hammer, M., & Grand, J. G. (2019). Gastric dilatation and volvulus in a 5-month-old Bernese mountain dog. The Canadian veterinary journal = La revue veterinaire canadienne, 60(6), 587–590.

Case #2:

Marley, a 13 year old male neutered Labrador Retriever was presented to the veterinarian after his owner had noticed signs of pain/discomfort as Marley was refusing to move from the lying position and distention in his abdomen. After the veterinarian had assessed Marley’s condition, it was determined that he had Gastric Dilatation Volvulus, “his stomach was twisted” (Marley and Me). A tube was attempted to be placed to help drain the excess fluid build up in the stomach but the tube was unable to get into the stomach. This is what had worked the previous time, but the stomach was too twisted and the cardiac sphincter was blocked. Unfortunately, due to Marley’s condition and his age, the doctor and owners decided to not pursue further surgical treatment.

Questions:

-After reviewing the case, what are your initial thoughts?

– What aspect of the history would make you suspect GDV?

– What clinical signs did you notice in Marley that could have led you to know that he had GDV?

Reference: Marley and Me Movie

KNOWLEDGE CHECK