Pig Diarrhea: Causes, Dehydration Risks & What to Do

Diarrhea in pigs has many possible causes, and age matters. In piglets, infectious causes are especially important because illnesses such as enterotoxigenic E. coli, rotavirus, and coccidiosis can cause watery diarrhea and rapid dehydration. Merck notes that E. coli diarrhea in pigs can become severe quickly, with dehydration, acidosis, and even death, while rotavirus commonly affects nursing and recently weaned pigs and causes malabsorptive diarrhea. Coccidiosis is another common cause in young piglets, often producing creamy to watery yellow diarrhea and poor growth.

In older pigs and pet pigs, diarrhea may also follow sudden feed changes, overeating rich treats, poor-quality or moldy feed, contaminated water, overcrowding, stress, or parasite exposure. Some infectious diseases can cause mucus or blood in the stool, especially when the large intestine is involved. Swine dysentery is one example associated with mucus and hemorrhage in the colon.

Because the list of possibilities is broad, your vet usually looks at the pig's age, housing, diet history, exposure to other pigs, and the appearance of the stool before deciding which tests make sense. That is why two pigs with "diarrhea" may need very different care plans.

See your vet immediately if your pig is a young piglet, has repeated watery diarrhea, seems weak, cannot stay hydrated, stops nursing or eating, has blood or large amounts of mucus in the stool, vomits, develops a fever, or becomes hard to wake. Diarrhea can move from mild to dangerous fast in pigs because fluid and electrolyte losses add up quickly.

A same-day veterinary visit is also wise if diarrhea lasts more than about 24 hours, keeps recurring, or affects more than one pig in the home or group. Multiple pigs with diarrhea can point to a contagious or environmental problem that needs prompt attention.

You may be able to monitor briefly at home only if your pig is bright, alert, still drinking, still interested in food, and passing just mildly soft stool without blood. Even then, call your vet for guidance, especially if your pig is very young, elderly, pregnant, or has other health issues. If you are unsure whether your pig is dehydrated, it is safer to have your vet assess them.

Your vet will start with a physical exam and hydration assessment. They may check body temperature, gum moisture, eye position, body condition, belly comfort, and whether your pig is still eating and drinking. In a dehydrated pig, the first priority is often fluid support and stabilization.

Diagnostic testing depends on the situation. Common options include a fecal exam for parasites or coccidia, fecal culture or PCR testing when bacterial disease is suspected, and bloodwork to look for dehydration, electrolyte changes, or infection. Merck notes that fecal sampling is a main diagnostic tool in older pigs with diarrhea, and culture can help identify conditions such as salmonellosis or swine dysentery.

Treatment is based on the likely cause and severity. Your vet may recommend oral electrolytes for mild cases, injectable or IV fluids for dehydration, anti-parasitic treatment when parasites are found, and carefully selected medications if a bacterial cause is suspected. They may also review feed, water access, sanitation, bedding, and recent stressors because management changes are often part of recovery.

Home care should only be used with your vet's guidance and only for pigs that are still bright, drinking, and not showing emergency signs. Keep your pig warm, dry, and in a clean area with easy access to fresh water. If your vet recommends an oral electrolyte product, use it exactly as directed. Merck notes that oral electrolyte solutions can be helpful in pigs with diarrheal disease, especially when dehydration is still mild.

Offer the regular balanced pig diet unless your vet advises a temporary change. Avoid sudden feed switches, rich treats, table scraps, and anything spoiled or moldy. Clean water bowls, feeders, and soiled bedding often. If you have more than one pig, separate the sick pig when possible until your vet helps you decide whether the problem may be infectious.

Track stool appearance, appetite, water intake, energy level, and body weight if you can do so safely. If diarrhea becomes more watery, lasts longer than expected, or your pig seems weaker, stop home monitoring and contact your vet right away. The biggest home-care goal is preventing dehydration while your vet works with you to find the cause.