Dogs that often pass gas can embarrass or distress their owners. The most common cause of flatulence is swallowing large amounts of air while gulping food. The next is eating highly fermentable foods such as beans, cauliflower, cabbage, and soybeans. Flatulence also occurs with malabsorption syndromes. The excess gas is related to incomplete digestion of carbohydrates. Boxers are renowned for flatulence problems.
A sudden bout of flatulence, accompanied by abdominal discomfort, loss of appetite, or diarrhea, is an indication to seek veterinary attention.
Treatment: It’s important to first rule out any malabsorption syndrome. Change the dog’s food to a highly digestible, low-fiber diet, and avoid giving table scraps. Feed three small meals instead of one large meal to keep the dog from gulping food and swallowing air. If this does not stop the flatulence, consider switching to a prescription diet, available from your veterinarian.
If further treatment is desired, simethicone can be given to absorb intestinal gas. Simethicone is available over the counter for people as a liquid or tablets. Ask your veterinarian about the proper dose for your dog. Charcoal-based treats and biscuits, and supplements that contain yucca, may also assist with gas.
Malabsorption is not a specific disease, but occurs as a consequence of some underlying disorder of the small bowel or the pancreas. In malabsorption syndrome, the dog either does not digest food or does not absorb the products of digestion from the small intestine. Dogs suffering from malabsorption are underweight and malnourished despite a voracious appetite. Diarrhea occurs three or four times a day. The stools are typically large, rancid smelling, and contain a great deal of fat. The hair around the anus may be oily or greasy.
Predisposing causes of malabsorption include exocrine pancreatic insufficiency, permanent damage to the intestinal mucosa following infectious enteritis, inflammatory bowel disease with inflamed or destroyed intestinal mucosa, surgical removal of a major portion of the small bowel, and primary diseases of the small intestine. Soft Coated Wheaten Terriers may suffer from a protein-losing enteropathy, where they don’t properly digest and absorb protein.
Idiopathic villous atrophy is one of the primary diseases of the small intestine. Villi are microscopic hair like structures that make up the absorptive surface of the small bowel. In a dog with villous atrophy these structures are blunted and poorly developed. Idiopathic villous atrophy occurs most often in German Shepherd Dogs. A similar hereditary disease is wheat-sensitive or gluten-sensitive enteropathy, described in Irish Setters.
Small intestinal bacterial overgrowth has been identified as another important cause of malabsorption. German Shepherd Dogs, Basenjis, and Chinese Shar-Pei have an increased incidence. Affected dogs develop an abundant and abnormal bacterial flora in the small intestine, which causes foul-smelling diarrhea. Some cases have been associated with exocrine pancreatic insufficiency, inflammatory bowel disease, or stagnant loops of bowel caused by intestinal surgery. In German Shepherd Dogs and Chinese Shar-Pei, the condition may be related to a specific immune deficiency. In the majority of cases the cause of the bacterial overgrowth is unknown. In many cases the cause of malabsorption can be identified through special diagnostic tests, including stool analysis and an intestinal biopsy.
Treatment: Treatment is directed toward the specific disease. Dogs with villous atrophy are managed with gluten-free prescription diets. Small intestinal bacterial overgrowth usually responds to one or more courses of an oral broad-spectrum antibiotic. The addition of probiotics and live culture yogurt products may help in treatment.
WebMD Veterinary Reference from "Dog Owner's Home Veterinary Handbook"