BLOAT

There are few ailments in veterinary medicine that rival the seriousness and immediacy of canine “bloat,” also known as gastric dilatation-volvulus (GDV). Once the bloat occurs, it is the speed at which treatment is administered that determines whether or not your dog will live or die.

Our Health Co-ordinator is :- Lynne Dale.

Contact :-Lynne Dale 01924 255590

What is Bloat?

Bloat occurs when something goes wrong during digestion of food. Something causes gases to build up in the stomach so fast that the stomach blows up like a balloon, stretching the organ so much that normal circulation of blood to and from the heart is cutoff. The stretching itself and the lack of blood to the stomach’s cells can cause cell death, or necrosis. What makes it even worse and more immediately serious is when the stomach actually “twists and turns” (known as volvulus) at the top near the esophagus and at the bottom of the stomach at the pyloric valve. Picture a tootsie roll candy that’s got a wrapper twisted at both ends keeping the candy lodged inside the paper. That is exactly what happens to the stomach during bloat with volvulus. Gas is trapped and can’t escape as a burp or the other end as “passing gas.” The gas builds and builds as it becomes trapped within the stomach. The stomach grows so large it cuts off circulation, as mentioned above, and irreversible damage is done to the cells. The dog goes into shock and then cardiac arrest. This can happen within several hours after the start of bloat. That is why if you suspect your dog is experiencing this problem, you must RUSH THE DOG IMMEDIATELY to the vet or animal hospital.

What Causes Bloat?

It is not really known what exactly trigers bloat to occur. Scientists can only make guesses due to the data taken from dogs that have experienced it. When they’ve tried to recreate the bloating conditions in a lab with test dogs, they were always unsuccessful at causing the bloat to occur intentionally.

A few examples of what scientists believe to be contributing factors to the causes of bloat are listed below:

1. Large meals eaten at one time. They recommend serving your dog two smaller meals a day, rather than just one big one.

2. Rigorous exercise done either right before a meal or right after one. You should wait one hour before feeding after exercise and one hour after eating before you let your dog run around.

3. Dry food given that is high in grain, which causes fermentation during digestion which causes gas. Dry food should have meat, meat meal and bone meal listed within the first few ingredients, not grain. In other words, dry food should have more meat than grain in its ingredients. [some texts claim this is not true, but most do agree with it.]

4. If only dry food is given, some people moisten it with water if it is a high-end dog food. However, with lesser quality foods, less meat-based dog food, the ones that are mostly grains, it is better to NOT wet the food, since water mixed with grain will start fermentation, a process that has by-products of gas. But if the food is mostly meat, it’s OK, and can actually help with digestion. Mix dry food with canned food if possible.

5. Gulping large amounts of water at one time during meals. Keep water within the dog’s reach at all times, except during meals.

6. Be careful of snacks and biscuits that are high in carbohydrates. Grains are carbohydrates.

7. Avoid dog food high in citric acid used as a preservative and also food that is high in fat.

Other Factors which Increase Risk of Bloat:-

1. Dog’s Breed—Large-breed dogs are most susceptible, although on occasion, small dogs may bloat too.

2. Dogs that are “deep-chested.” This means the length of the chest from backbone to sternum is long and the width of the chest is narrower.

3. Dogs that have ancestor-history of bloating. It’s thought to be hereditary.

4. Underweight, or thin, dogs.

5. Anxious or fearful temperament. These dogs should always eat in an environment made as peaceful as possible for them.

6. Aggressive dogs. Numbers five and six indicate that “nerves” or emotions can play a role in triggering a bloat episode.

7. Male dogs appear to get it more than females.

8. Dogs older than seven years of age are more at risk than those that are younger.

Signs and Symptoms

Know your dog. Most of the symptoms are behavioral, at least in the very beginning, so your dog will start to act differently. The abdomen is stretched to many times its normal size due to an increase in gas. It will blow up like a balloon and is one of the first most obvious signs. In some cases, this part of the bloat event can’t be seen. But, usually you can see the distended abdomen which will also feel very hard to the touch, like a ball that has been pumped up with too much air.

This event causes SEVERE abdominal pain. So, you may see that your dog is acting uncomfortable, pacing the floor, not being about to find a comfortable position to lie down or may make sounds like he is in pain.

The biggest, most obvious symptom is that the dog appears to be nauseated. He will unsuccessfully attempt to vomit and will retch and gag, but nothing comes up, or very little, if any. He will also attempt to have a bowel movement, assume the position, but again, nothing comes out. Excessive drooling is also a common symptom.

IF ANY OF THESE THINGS HAPPEN, CALL YOUR VET OR RUSH YOUR DOG TO THE NEAREST ANIMAL HOSPITAL. It is better to be safe than sorry. As mentioned earlier, there are only a few hours available to handle this problem, so time is everything in a case of bloat. Your vet will put everything else aside to address your dog’s condition.

How do They Treat Bloat?

There are only two basic things that are done to the dog in the case of bloat. The first thing a vet may try is to insert a tube down the throat making a passage for the gas to escape. But if the stomach has twisted volvulus, surgery is the only solution. The vet will have to make an incision into the stomach and relieve the gas that way. While in there, he may decide to perform what is called gastropexy. This is where the stomach is actually stapled into its normal position, or anchored into place, so that it cannot blow up should there be another episode of bloat.

Even if the dog has been relieved of the bloat with just a tube and not surgery, he should be surgically examined regardless, so that the vet may assess the damage done by the episode. Damaged parts of the stomach may need to be removed, or the patient’s owner may decide to allow gastroplexy since many dogs that experience bloat often go through it again at a later date. Sometimes only a day or two later, they may bloat again.

From: Edward J. Hall, MA, Vet MB , PhD, DipECVIM-CA, MRCVS

Gastric dilatation-volvulus

Gastric dilatation-volvulus (syn. bloat, torsion) is a potentially life-threatening emergency that unfortunately appears prevalent in the setter breed. Whilst veterinary surgeons are now better at treating the condition, with improved survival rates, they still do not understand the cause nor how to prevent bloat from occurring.

The condition is probably multifactorial and recognised predispositions include deep‑chested dogs, gulping food (and swallowing air), and temperament, but there is anecdotal evidence that there is a genetic predisposition. However, whether this relates simply to conformation or other factors is unknown. That is why submitting DNA to the AHT from both healthy setters and those that get bloat is important if we are ever to get an answer to this devastating condition.

If, sadly, bloat occurs, emergency surgery after stabilisation is indicated, and owners should ensure their vet performs a “gastropexy”, i.e. fixing of the stomach to prevent future twisting.

Mortality and Morbidity due to Gastric Dilatation-Volvulus Syndrome in Pedigree Dogs in the UK.

Authors: Katy Evans and Vicki Adams.

Published: Journal of Small Animal Practice (July 2010) vol 51, pp 376-381

This study, conducted by two epidemiologists at the Animal Health Trust, used data collected in the 2004 Kennel Club/BSAVA Scientific Committee Purebred Dog Health Survey. This surveyed 15,881 dogs from 165 KC‑recognised breeds. The authors identified illness (morbidity) and death (mortality) in each breed due to bloat (gastric dilatation-volvulus syndrome). The four breeds with the highest prevalence of developing bloat were the Grand Bleu de Gascogne, bloodhound, otterhound and Irish setter. However, it is disappointing to note that the British Association for German shepherd dogs refused to provide data.

There were dogs in different 65 breeds that died of bloat, and bloat was the cause of 2.5% of all deaths. From the available data the authors were able to calculate the relative risk of illness or death for each breed, adjusting the data in proportion to the number of dogs in each breed. All the breeds that appeared to be at increased risk were large or giant breeds except for the basset hound and chow chow. The highest risk of illness and death was in the Grand Bleu de Gascogne and bloodhound.

Breed                                                                       Prevalence ratio*

Grand Bleu de Gascogne                                                        31.1

Bloodhound                                                                            21.8

Otterhound                                                                              13.1

Irish setter                                                                               12.6

*The  higher the number the greater the risk of developing bloat, where 1 indicates no increased risk.

Because the number of bloat cases was numerically greater in setters (i.e., 49 bloats in Irish setters but only 3 in Grand Bleu de Gascogne), reflecting breed popularity, the results for the setter are more statistically valid, and regrettably the Irish setter is clearly at increased risk of developing bloat.

In conclusion, bloat is a serious, and often fatal condition in the breed, and the Breed Club Health Coordinators recommend all setter owners submit DNA samples to the Animal Health Trust in the hope of finding a genetic basis to this disease so that it can be eliminated through responsible breeding programmes.

BLOAT SURVEY

The AHT/KC survey of Irish setters last year, with financial support of the JISBC, was aimed primarily at gathering evidence to prove that bloat is heritable,. If proven, DNA samples could then be evaluated for possible genetic markers. However, it was always understood that it was very unlikely to be a simple inheritance (i.e. single gene mutation) pattern. Whilst there may be genetic susceptibility, environmental factors are likely to play a significant role.Regrettably, although the results raised a suspicion that there is an inherited component to the condition, confounding factors prevented the results reaching statistical significance and therefore proof. The number of respondents, and the fact that some of the dogs alive at the time of the survey may go on to develop bloat later in life confounded any clear conclusion.The recommendation must therefore be that the breed prospectively collects DNA samples from dogs that suffer bloat. Whilst this outcome is disappointing, it is recommended that we work with the AHT to collect DNA samples and pedigrees of dogs when they suffer bloat confirmed by surgery or post mortem.As you will be aware, the survey also  gathered information on a number of other conditions. This data has not yet been analysed, but I have asked Tom Lewis (KC, formerly AHT) to analyse results pertaining to megaoesophagus and epilepsy, where it is more likely that heritability can be proven.

Ed Hall.

22/3/15

 

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