Baker's yeast (Saccharomyces cerevisiae) is a live leavening organism sold as active dry, instant, and fresh compressed cakes for bread, pizza dough, rolls, and brewing starters. It activates with warmth and moisture. It ferments sugars to produce carbon dioxide and alcohol. Raw yeast dough may expand rapidly in a warm stomach.
Exposure often comes from dough left to rise on counters or from discarded scraps in trash bins. As dough expands, it may cause painful bloating, and fermentation alcohol can add systemic toxicity. Brewing yeast slurries and sourdough starters pose similar concerns when ingested in quantity. Pizza dough balls and bread-machine dough are common household exposure points.
Nutritional yeast is a different inactive product used as seasoning and does not rise like baker's yeast. For pets, keep all active dough and starter cultures out of reach and seek urgent veterinary advice after ingestion.
Signs after yeast dough ingestion may include abdominal distension, repeated retching, unsteady gait, and lethargy as alcohol is absorbed. Warm environments may speed fermentation and gas expansion. Rapid assessment is important when proofing dough is accessed.
