Duodenum

The duodenum (duodenum) is the first section of the small intestine in dogs – a piece of intestine about 20–30 cm long directly behind the stomach. Here, the acidic chyme from the stomach is mixed with bile and pancreatic enzymes so that it is ready for nutrient absorption in the rest of the small intestine.

Why is the duodenum so important for digestion?

The duodenum neutralises aggressive stomach acid with bile and pancreatic juice. Without this neutralisation, the acid would corrode the subsequent sections of the intestine. At the same time, the breakdown of fats, proteins and carbohydrates by specialised enzymes begins here.

You usually notice problems in this area because your dog vomits after eating or has soft faeces – the chyme can no longer be properly processed then.

Which diseases of the duodenum occur in dogs?

Inflammations (duodenitis) are the most common. They arise from parasitic infestation, food intolerances or stress. Your dog then often vomits yellow bile – especially in the morning on an empty stomach.

Stomach ulcers often also affect the duodenum. They arise when stomach acid production gets out of balance – for example due to long-term painkiller administration or chronic stress. The vomit can then look dark or bloody.

Foreign body blockages occur less frequently here than in the stomach, but can occur with larger swallowed objects. Your dog then retches unsuccessfully and has severe abdominal pain.

When should I go to the vet?

Immediately in case of bloody vomiting or if your dog becomes apathetic and no longer eats. Repeated vomiting of yellow bile over several days also needs to be clarified.

Less urgent, but still important: chronic digestive problems, recurring abdominal pain or unexplained weight loss. The vet can assess via ultrasound or X-ray whether the duodenum looks normal.

How can I prevent duodenal problems?

Regular feeding times relieve the entire digestive tract. A dog that eats every 12 hours produces digestive juices more evenly than a dog with irregular meals.

Avoid abrupt changes in food – the duodenum needs time to adjust to new enzymes. A transition over 7–10 days is gentler.

Make sure that your dog does not swallow foreign objects. Especially dogs that eat everything they find need consistent control during the walk.