Intermittent vomiting within one to two hours of eating is the most common sign of pyloric stenosis. The food will appear undigested, pretty much looking just as it did when eaten. The sphincter may not always be constricting or spastic, therefore, some meals may pass without vomiting. Additionally, liquid diets or water will pass through the narrowed sphincter more easily than bulky foods. In severe cases, weight loss may develop.
Many dogs live normal lives with only occasional episodes of vomiting.
It appears the muscular spasms are not always constant in these cases. If a dog is exhibiting severe stomach outflow restrictions from a more constant pyloric stenosis, then weight loss and even death can result. A diagnosis is not always easy. A careful history of vomiting in relation to eating must be evaluated. Once diagnosed, surgery provides the best cure.