Enteritis in Ducks: Causes of Intestinal Inflammation and Diarrhea

Enteritis is inflammation of the intestines. In ducks, that inflammation can interfere with normal digestion and water absorption, so droppings may become loose, watery, green, foul-smelling, or sometimes bloody. Affected ducks may also lose weight, act quiet, drink more, or become dehydrated.

Enteritis is not one single disease. It is a syndrome with many possible causes, including viruses, bacteria, parasites, dietary upset, toxins, and poor sanitation. One well-known infectious cause in waterfowl is duck viral enteritis, also called duck plague, which can cause watery or bloody diarrhea and sudden deaths in domestic and wild ducks.

Because ducks can decline quickly once diarrhea and dehydration start, it helps to think of enteritis as a sign that your duck needs prompt evaluation rather than a diagnosis by itself. Your vet can help sort out whether the problem is mild digestive irritation, a flock-management issue, or a serious contagious disease.

Enteritis in ducks has many possible causes. Infectious causes include viruses, bacteria, and parasites. Duck viral enteritis is a highly contagious herpesvirus disease of ducks, geese, and swans that can cause watery or bloody diarrhea, weakness, dehydration, and sudden death. Other infectious contributors to intestinal disease or diarrhea in poultry and ducks can include bacterial overgrowth, salmonellosis, and protozoal infections such as Cochlosoma anatis.

Management and environmental factors matter too. Poor sanitation, contaminated standing water, crowding, stress, abrupt feed changes, moldy or spoiled feed, and exposure to wild waterfowl can all increase risk. Merck notes that intestinal disease in poultry can also be promoted when the gut lining or normal gut flora are disrupted, and some diets can predispose birds to enteric problems.

Toxins are another concern. Ducks are particularly sensitive to some feed-related toxins, including certain mycotoxins, which may contribute to diarrhea and poor condition. In backyard or mixed-species settings, your vet may also consider heavy parasite exposure, contaminated treats, or access to unsafe plants, chemicals, or stagnant water.

Because the list is broad, treatment should be based on the likely cause in your duck or flock. Supportive care may look similar at first, but the right long-term plan depends on whether the problem is infectious, nutritional, toxic, or environmental.

Your vet will usually start with the basics: history, flock size, age of the ducks, diet, water source, housing, exposure to wild birds, and whether any birds have died suddenly. A physical exam looks for dehydration, weight loss, weakness, vent staining, abdominal pain, and signs of systemic illness.

Testing often depends on how sick the duck is and whether one bird or the whole flock is affected. Common options include a fecal exam, direct microscopic evaluation of droppings or intestinal material for parasites or protozoa, crop or cloacal swabs, bloodwork in valuable birds, and bacterial culture or PCR testing when a contagious disease is suspected. In suspected duck viral enteritis, diagnosis may involve PCR, virus isolation, or necropsy findings in birds that have died.

If several ducks are ill, your vet may recommend flock-level diagnostics rather than treating one bird in isolation. Necropsy of a freshly deceased bird can be one of the fastest and most useful ways to identify a serious infectious cause. That can guide treatment, isolation, and biosecurity steps for the rest of the flock.

Prevention starts with clean water, clean feed, and good flock hygiene. Replace dirty water often, keep feed dry and protected from rodents and wild birds, and remove spoiled feed promptly. Avoid sudden diet changes when possible. If you need to change feed, do it gradually so the intestinal tract has time to adjust.

Biosecurity matters, especially for ducks because contact with wild waterfowl can introduce serious disease. Cornell recommends maintaining a biosecurity program for duck premises, and USDA advises using covered enclosures or netting to reduce contact between domestic birds and wild birds. Quarantine new arrivals before mixing them with the flock, and clean boots, tools, and carriers between groups.

Good management also lowers risk. Reduce crowding, keep bedding dry, clean up fecal buildup, and address standing water that becomes heavily contaminated. If you have repeated diarrhea problems, ask your vet to review your feeding program, parasite control approach, and housing setup. In some production or specialty settings, vaccination against duck viral enteritis may be part of prevention planning, but that decision should be made with your vet based on local risk and flock type.