There are many causes of abdominal distension. A good rule to follow is: the more quickly the distension seems to occur, the more serious it is likely to be. If you’re worried that your pet may have abdominal distension, it should certainly be examined by a vet.
If your dog (especially large breeds) develops a rapidly swollen abdomen, often accompanied by attempts to retch or vomit, it should see a vet immediately. These signs could mean your dog is getting a gastric dilatation and volvulus (GDV – a twisted stomach). In these cases, dogs require prompt surgery to correct this life-threatening problem.