Early recognition of GDV (bloat) could save your dog’s life
What is gastric-dilatation and volvulus (GDV)? Is my dog at risk?
Gastric dilatation and volvulus, or GDV as it is commonly abbreviated, is a relatively common clinical syndrome seen in large / giant breeds of dog. Dilatation refers to bloating of the stomach with gas, and volvulus refers to twisting of the stomach about its axis. The cause of this syndrome is not completely understood. In fact it is quite controversial which occurs first; the bloat or the volvulus (twisting). Indeed both components do not have to occur together and some patients will develop relatively simple bloat alone.
GDV is a potentially life threatening condition and emergency veterinary attention should be sought immediately if it is suspected.
Why is GDV potentially life-threatening to dogs?
There are a number of serious and potentially fatal consequences that occur as a result of GDV. Initially the severe distension of the stomach stretches the blood vessels over its surface reducing the blood supply to the stomach walls. This is made worse by the twisting of the stomach which also twists the blood vessels, effectively shutting off blood supply to the stomach. A lack of blood flow means there is a lack of oxygen and nutrients delivered to the stomach and waste products are not removed. As with any organ this will result in parts of it dying. This process happens very quickly and in severe cases could result in part of the stomach wall rupturing and releasing its contents into the abdomen.
The large distended stomach occupies much more space inside the abdominal cavity and compresses surrounding structures. Severe distension puts pressure on the diaphragm and interferes with the patient’s ability to breath. It also applies pressure to a large blood vessel in the abdomen (the vena cava) that normally returns blood from the back half of the body to the heart. Pressure on this vessel obstructs flow therefore reducing the amount of blood returned. If blood can’t be returned to the heart, then it in turn can’t pump it out to the rest of the body. If there is insufficient blood being pumped, the blood pressure falls dramatically making the patient weak and potentially leading to collapse.
To add insult to injury, other organs in the body such as the lungs, kidneys, liver and intestines do not receive a blood supply and begin to fail. The lack of a functional circulation also means that toxic products build up in these organs that further compromise the patient. These changes can happen in a matter of hours, emphasizing the importance of early veterinary attention.
What are the symptoms of GDV in dogs?
The symptoms generally include obvious distension or enlargement of the abdomen with unproductive vomiting or retching. The patient may drool excessively and appear restless or agitated. As the condition progresses the patient may become increasingly weak or even develop shock and collapse.
What is the treatment for GDV?
The age and breed of the patient coupled with the clinical signs of a severely bloated abdomen will make your vet highly suspicious of this condition. They will immediately place one or more an intra-venous catheters to allow administration of fluids to support the circulation and dilute toxins in the blood. They may also analyse the patient’s blood to assess the severity of organ damage.
The next stage involves attempts to decompress the stomach. This is usually accomplished by passage of a specially designed tube through the mouth down into the stomach. There is a gag that can be used to assist in this process but many patients will require sedation or anaesthesia to complete the task. It can be very challenging or sometimes impossible to perform stomach tubing. This is particularly the case when the stomach is twisted 360 degrees or more. In this instance a cannula (tube) may have to be inserted through the body wall and into the stomach to allow deflation. Deflation is clearly an imperative step because it will relieve pressure on the diaphragm and help restore blood flow back to the heart through the vena cava.
This image demonstrates the appearance of a typical GDV before de-rotation during emergency surgery.
Radiographs of the abdomen are often required to help distinguish between simple dilatation and dilatation with volvulus. In the latter case surgery will be required as soon as the patient is stabilised. The aim of the surgery is to de-rotate the stomach and assess it for areas of devitalisation. If there are areas of the stomach that have undergone necrosis (died), these need to be removed surgically.
It is vital that the stomach is attached to the inside of the body wall. This is called a gastropexy and it will prevent volvulus in the future. This is essential as up to three quarters of the patients that do not have this performed will have another episode in the future. This also applies to those patients suffering with bloat alone as they have the same risk.
What are the risk factors for GDV in dogs?
There are several factors that have been clearly demonstrated to increase an individual’s risk of developing this condition. These include:
- Being a purebred large / giant breed
- Having a deep and narrow chest conformation
- Having a history of previous bloat
- Having a history of bloat or GDV in a first degree relative (parent or sibling)
- Increasing age
- Having an aggressive or fearful temperament
- Eating fewer meals per day
- Eating rapidly
- Being fed a food with small particle size
- Exercising or stress after a meal
What breeds are predisposed to this condition?
The breeds most commonly affected are large purebred dogs that have a narrow deep chest confirmation. Those at most risk include:
- Great Danes
- Gordon setters
- Irish setters
- St. Bernard’s
- Standard poodles
- Bassett hounds
Although these are the breeds we typically see GDV in, it is worthy to remember that it can happen in any patient.
What is the prognosis?
With improved understanding of the secondary consequences of GDV and excellent anaesthesia, surgical and post-operative care now available for veterinary patients a good prognosis can be achieved for this condition. Survival rates of 73-90% would be typical. There will always be a range quoted for survival because individual patient’s circumstances in terms of severity, age, general health and treatment received will have an impact on the outcome. One important factor that has been shown to decrease the survival is the presence of clinical signs for greater than six hours. This emphasizes the importance of prompt veterinary attention in all cases.
If you are in any doubt that your dog is suffering from bloat or GDV, please call your vet immediately.
In the next article in this series we’ll look at the so-called ‘tummy tacking’ procedure that should be carried out after a case of GDV.