What causes a dog to vomit yellow?

Answer:
Yellow vomitus is colored this way due to bile refluxing from the proximal duodenum back through the pylorus and into the stomach. It can be a sign of stomach or upper intestinal problems and the animal should be evaluated by a veterinarian.
First answer by SummerMaple. Last edit by SummerMaple. Contributor trust: 63 [recommend contributor recommended]. Question popularity: 0 [recommend question].