How Gas Affects Dogs
When excess gas forms in the stomach or intestine, it eventually has to be released through one end of the gastrointestinal tract or the other. The clinical signs of gas in dogs depend largely upon which end of the dog the gas is released from.
Symptoms of Gas
Owners of dogs with gastrointestinal gas usually notice one or more of the following symptoms:
- Distended abdomen
- Audible passage of gas from the anus (with or without odor)
- Rumbling sounds coming from the abdomen (“borborygmus”)
- Abdominal discomfort (usually mild)
- Burping (belching; eructation)
- A feces-like smell near their dog
- Vomiting, diarrhea, weight loss, lack of appetite (may be present if flatulence is caused by underlying gastrointestinal disease)
Most natural gastrointestinal gas in dogs is odorless. The small amount that passes with a foul smell usually contains ammonia, indole, skatole, volatile amines, hydrogen sulfide and/or short-chain fatty acids. It can be caused by ingestion of cruciferous vegetables, onions, high-protein diets, endogenous mucin and bile acids.
Dogs at Increased Risk
Brachycephalic breeds, which are those with a very short, flat muzzle and a wide head, are predisposed to developing gastrointestinal gas, primarily because they swallow excess air while eating due to the unusual shape of their skull. These breeds include the Boston Terrier, Boxer, Bulldog, French Bulldog, King Charles Cavalier Spaniel, Pekingese and Pug, among others. Flatulence is also more prevalent in especially greedy eaters, because as they gulp their food they tend also to ingest a lot of air (called “aerophagia”). Some reports suggest that working and sporting breeds may be at an increased risk. Dogs that are especially nervous or finicky eaters, and those with a sedentary lifestyle, are also more likely to become gassy. Obese dogs are more likely to be sedentary and thus are also prone to flatulence.