GASTRIC DILATATION/VOLVULUS (TORSION)
by Karyn A. Colman, B.Vet.Med., M.R.C.V.S.
Gastric dilatation/volvulus (or bloat &/or gastric torsion to most of us!) is one of the the biggest emergency surgical problems seen in dogs. It is most common in middle-aged large and giant breeds of dog, usually with deep chests. A relatively recent (1989) survey of cases seen in pure-bred dogs recorded over the previous 9 years from 12 American veterinary teaching hospitals showed Alaskan Malamutes as the 14th breed in a ranking of risk. A total of 1,934 cases were recorded. Great Danes were ranked 1st, followed by St. Bernards, Weimeraners, Irish and then Gordon Setters 5th.
I, myself, have seen it in Standard Poodles (ranked 6th),one Afghan (not on the list!) and German Shepherds (ranked 13th). The ranking takes into account the number of cases seen and the number of dogs of that breed seen for some other problem. The following table shows the total numbers affected for some breeds:
Number of Cases
|Great Dane *
|St. Bernard *
|Irish Setter *
|Standard Poodle *
|Golden Retriever #
- Risk is significantly higher than for all dogs combined
- Risk is significantly lower than for all dogs combined
It was also found that pure-bred dogs were 3 times more likely to develop bloat than crossbreeds!
Although surgical techniques and recurrence rates have dropped dramatically in recent years, the mortality rate is still high. Dogs may die of complications during or just after surgery, before surgery can be performed or may be euthanized. In the same study as above, 30.9% of the 1,934 dogs died or were euthanized.
The cause of the condition is not really understood and is thought to be multifactorial (i.e. there are several implicated factors) including delayed emptying of the stomach, ingestion of air whilst eating, diet and feeding frequency (particularly feeding dry food just once a day - generally at least 2 feeds per day are recommended for larger breeds), loosening of internal ligaments supporting the stomach &/or bowel and abnormalities of the stomach contractions. Increased activity after feeding (eg. excitement or exercise) has also been suggested as a causative factor.
Clinical signs include an enlarged abdomen (belly), excessive salivation, retching and attempts to vomit (without any result), restlessness and hyperventilation (excessive and rapid breathing - usually panting). If not treated the dog becomes unable to stand and goes into 'shock' which is usually fatal.
Immediate treatment to decompress the stomach is necessary whether by stomach tube or inserting a wide-bore needle through the skin into the stomach. Then treatment for shock - intravenous fluids - is usually required before or concurrent with anaesthesia as is antibiotic cover to prevent peritonitis. Surgery is then performed, with very careful monitoring of the patient under the anaesthetic (there is a greatly increased anaesthetic risk in gastric torsion cases), with the aim of correction the dilatation/volvulus, assessing the stomach and spleen (which is usually involved in cases of torsion) and removal of any badly damaged tissue (the torsion cuts off the blood supply to parts of the stomach and the spleen so the tissue can die as a result). In some cases the stomach is also fixed in place to try to prevent recurrence (not always effective, however).
If the blood supply to the stomach wall has been compromised then the outlook for the dog is not good. Surgery to remove part of the stomach is fraught with difficulty and has a high mortality rate. It is also difficult to see if the tissue has been damaged, sometimes, and if it subsequently dies, severe peritonitis and death of the dog is the usual result.
Post-operative care is intensive, with fluid therapy (intravenous fluids), monitoring of various parameters, no food by mouth initially followed by fluids/liquid foods only and building up to solid foods over several days.
Unfortunately, despite increased use of surgical fixation techniques of the stomach wall, recurrence is a real problem since the ligaments and tissues have all been stretched and are loose following a torsion. The Americans report considerable success with gastropexy (fixation of the stomach = stapling) but in the UK it is not so common and results have not always been so good. There is still some discussion on the best ways to prevent recurrence and, as far as I know, no definite conclusions have been drawn.
As far as the condition in Malamutes is concerned, it would appear that the breed is susceptible, due to its size and build, although cases are not numerous (not that Malamutes are numerous!). If a dog is susceptible then it may be difficult to prevent but if you feed a dry food, please feed at least twice a day (the Malamute likes it because it has two meals to look forward to!) and try to feed after exercise - but not immediately after a strenuous workout! Wetting dry food can help to stop the dog bolting the food and also reduces the amount of air the dog swallows when eating.
Interestingly, I have heard that the condition is a problem in Siberian Huskies in the UK, although they were not mentioned at all in the American survey! I believe it is something puppy buyers are warned about!
Jacobs-Knoll, J; News from the Canine Gastric Dilatation-Volvulus Research Program, School of Veterinary Medicine, Perdue University; AMCA Newsletter September 1993.
Note: Current studies now shed some doubt as whether feeding and exersize are the true causes of a bloat / torsion condition. It is possible that the tendency toward the condition is hereditary, and exersize shortly before or after feeding may "activate" this predisposed tendency to bloat. However, dogs have been known to "bloat" with no discernable cause.