NECROTIC ENTERITIS IN PIGS: SYMPTOMS AND EFFECTIVE PREVENTION AND TREATMENT

Necrotic enteritis in pigs is a serious gastrointestinal disease caused by Clostridium perfringens type C. It commonly occurs in nursing piglets, especially during the first few days after birth. The disease can progress rapidly, causing bloody diarrhea, hemorrhagic inflammation, intestinal necrosis, severe weakness, and death within a short period.
In this article, the Fivevet Field Technical Department shares important information to help farms better understand the causes, symptoms, lesions, diagnosis, prevention, and treatment of necrotic enteritis in pigs. 1. The cause of necrotic enteritis in pigs
Necrotic enteritis in pigs is an infectious gastrointestinal disease that mainly affects nursing piglets. The disease is characterized by inflammation, hemorrhage, and necrosis of the intestinal lining, causing bloody diarrhea, dehydration, severe weakness, and rapid death in piglets.
The main cause of the disease is Clostridium perfringens type C. This is a Gram-positive, rod-shaped, spore-forming bacterium that grows under anaerobic conditions.
Clostridium perfringens is naturally present in the digestive tract of animals (from 102–105 CFU/ml) and can also be found in soil, feces, feed, drinking water, and bedding. The bacteria can grow at temperatures ranging from 10–52°C (ideally 40–45°C), with an optimal pH of 6–7. Under favorable conditions, the bacteria multiply rapidly in the intestines and produce toxins that damage the intestinal lining. These bacteria can double in number in just 7 minutes. When the bacterial concentration in intestinal fluid reaches 10⁶–10⁸ CFU/ml, they release toxins that cause enterotoxemia and trigger clinical signs.
Clostridium perfringens has five major types: A, B, C, D, and E, which produce around 30 different toxins. Four important toxins are alpha (α), beta (β), iota (ι), and epsilon (ε). In pigs, necrotic enteritis is mainly associated with β2-toxin produced by type C, although type A has also been detected in some cases.
Beta toxin can destroy the intestinal lining, causing inflammation, hemorrhage, necrosis, and systemic toxemia. Newborn piglets are especially susceptible because their digestive systems are not fully developed and their ability to break down the toxin is still limited.
The disease is mainly transmitted through the digestive tract. Piglets may ingest the bacteria from:
- Feces from sows or infected pigs.
- Contaminated teats, abdominal skin, and the area around the sow's anus.
- Pen floors, bedding, and farm equipment.
- Contaminated feed, drinking water, or the farrowing environment.
The disease is more likely to occur when farrowing pens are wet and poorly sanitized, piglets do not receive enough colostrum, their resistance is weak, they become chilled, or they are exposed to multiple stress factors.
2. Symptoms and lesions of necrotic enteritis in pigs
According to nhachannuoi, depending on the level of infection, the amount of toxin, and the piglet's resistance, the disease may appear in peracute, acute, or subacute forms.
2.1. Peracute form
- The peracute form usually develops very rapidly within the first 8 hours after birth.
- Piglets suddenly become weak, stop nursing, separate from the litter, show poor reflexes, and die quickly. Some piglets may die before clear signs of diarrhea appear.
- Because they are weak, piglets spend a lot of time lying down and are unable to move away from the sow, so their deaths may sometimes be mistaken for crushing by the sow.
- In some cases, piglets may develop dark red watery diarrhea or bloody stools before death.
2.2. Acute form
- The acute form is commonly seen in piglets 2–5 days old.
- Typical signs include rapid, sudden death and bloody diarrhea.
- After bloody diarrhea appears, piglets may die within a short period. When the disease occurs within the same litter, several piglets may become sick around the same time, resulting in a high mortality rate.
2.3. Subacute form
- In the subacute form, the disease progresses more slowly. Piglets often have prolonged diarrhea, with reddish-brown, yellow-brown, or pale yellow stools.
- The stool may contain mucus, foamy yellow-brown material, or pieces of shed intestinal lining. Piglets nurse poorly, develop rough coats, become dehydrated, lose weight quickly, and gradually become weaker.
- Piglets may die 2–3 days after becoming sick.
2.4. Lesions of necrotic enteritis in pigs
Lesions are usually concentrated in the small intestine. During necropsy, the following may be observed:
- The carcass becomes bloated quickly after death because the bacteria produce gas.
- The skin and mucous membranes become pale due to blood loss.
- The intestinal contents include blood, dark red fluid, or reddish-brown material.
- The intestinal lining may become necrotic, slough off, and be covered by a pseudomembrane.
- In some cases, dark streaks may appear along both sides of the white midline in the abdominal area. In the acute and subacute forms, the intestines become inflamed and hemorrhagic, swollen, and thickened, causing intestinal distension. Once piglets have severe bloody diarrhea, extreme weakness, and serious intestinal necrosis, the chance of successful treatment is usually low. Therefore, proactive disease prevention is especially important.
3. Diagnosis of necrotic enteritis in pigs
Diagnosis should be based on a combination of the age at which the disease occurs, clinical signs, necropsy lesions, and laboratory tests.
3.1. Based on symptoms and lesions
The disease may be suspected when piglets show the following signs:
- The disease occurs mainly during the first few days after birth.
- Piglets have reddish-brown diarrhea or stools containing large amounts of blood.
- Piglets stop nursing, become severely weak, and die quickly.
- The small intestine becomes swollen and thickened, with hemorrhage and necrosis.
- The intestinal contents contain large amounts of blood or dark red fluid.
- However, bloody diarrhea alone should not be used to confirm the disease because this sign can also occur with several other intestinal diseases.
3.2. Based on laboratory tests
Common methods include:
- Collecting samples for direct smear staining of the intestinal lining.
- Culturing Clostridium bacteria.
- PCR genotyping.
4. Prevention of necrotic enteritis in pigs
For effective prevention, farms should combine cleaning and disinfection, proper farrowing-pen management, adequate colostrum intake for piglets, and an appropriate disease prevention program.
- Farrowing pens should be thoroughly cleaned, with feces and organic matter removed after each production cycle. After washing, allow the pens to dry before disinfection and before moving sows in for farrowing. Disinfectants that can be used include: Five-BGF, Five-B.K.G, Five-Iodine, Five-Perkon 3S,…
- Check the pigs' drinking water. If surface water is used, it should be filtered and treated with chlorine before being given to the pigs.
- Make sure piglets receive enough colostrum as early as possible, and regularly provide adequate essential nutrients in the feed to help keep pigs healthy and maintain good resistance.
- Regularly provide one of the following supplements to strengthen the immune system and help pigs cope with stress factors: Five-Anti Virus, Beta-Glucan.C garlic, Five-Prozyme 5 way, Five-Enzym, Five-Orgacid, Five-LacEnzym Garlic,…
- Use antibiotics active against Clostridium perfringens, such as TW5-Amox.600 or Five-Amoxcin Super, Five-AmoxClav for sows before farrowing and during lactation to help prevent disease in piglets.
- Vaccinating sows with a toxoid vaccine and maintaining strict sanitation of farrowing pens between production cycles are highly effective measures for disease prevention.
5. Treatment protocol for necrotic enteritis in pigs
When piglets show signs of suspected disease, treatment should begin as early as possible. Treatment should combine symptom control, appropriate antibiotics, fluid replacement, supportive care, and measures to help restore digestive function.
Some products that can support the treatment of necrotic enteritis in pigs Step 1: Treat the symptoms
For piglets with severe diarrhea, stools containing large amounts of blood, and increased intestinal motility, the following protocol may be used: Five-Vitamin K Inj + Five-Atropin + Five-Vitamin C Inj
For piglets showing signs of fever or pain, one of the following products may be used: Five-Anagin.C, Five-Metamax.50,…
Step 2: Use antibiotics
- Injectable antibiotics may include one of the following products: Five-Amox@.LA, Five-Kacolis, Five--Enxacin@la, Five-AmColiDex.LA, Five-Cefquin 25.
- Powdered antibiotics for mixing with drinking water or feed may include one of the following products: Five-Halquinol.60, TW5-Amox.600, Five-AC.15, Five-Colistin,…
Step 3: Replace fluids and electrolytes and provide supportive care
Piglets with severe diarrhea often lose fluids and electrolytes and become weak quickly. One of the following supportive products may be used: Five-Butasal, Five-Cafein, Five-ADE Inj,…
Step 4: Supplement probiotics, enzymes, and vitamins
After the acute condition has been brought under control, piglets should be encouraged to start eating early with easily digestible feed, divided into several small meals, while feed troughs and drinkers should be kept clean.
Probiotics, enzymes, vitamins, and organic acids can be added to help stabilize the digestive system, restore the intestinal lining, and improve nutrient absorption.
Products that may be used include: Five-Prozyme 5 Way, Five-Enzym, Five-Orgacid, Five-LacEnzym Garlic,…
Note:
- Piglets with severe diarrhea and stools containing large amounts of blood may develop anemia. Five-Fe.B12 may also be used as directed to provide iron and support blood formation.
- Piglets may be given 0.9% NaCl solution or Lactated Ringer's solution through intraperitoneal fluid administration.
- Follow the correct dosage, route of administration, contraindications, and withdrawal period for each product.
Necrotic enteritis in pigs caused by Clostridium perfringens type C usually progresses rapidly and causes a high mortality rate in newborn piglets. To control the disease effectively, farms should focus on farrowing-pen hygiene, making sure piglets receive enough colostrum, vaccinating sows, and taking early action as soon as piglets develop bloody diarrhea, stop nursing, or show unusual weakness.
This article was prepared by the Field Technical Department – Central No. 5 Veterinary Medicine Joint Stock Company (Fivevet).
Frequently Asked Questions
1. What causes necrotic enteritis in pigs?
The disease is mainly caused by Clostridium perfringens type C. The bacteria produce beta toxin, which causes hemorrhage and necrosis of the intestinal lining.
2. At what age does the disease usually occur in piglets?
The disease usually occurs in piglets during the first few days after birth and is most common in piglets 2–5 days old.
3. Which antibiotics are used to treat necrotic enteritis in pigs?
Antibiotics active against Clostridium perfringens, such as amoxicillin, amoxicillin combined with clavulanate, ceftiofur, cefquinome, or other appropriate antibiotics, may be used. The choice of medication should be based on the animal's condition, diagnostic results, and antibiotic sensitivity test results. Treatment should also begin early and follow the correct dosage and full treatment course under the guidance of a veterinarian.
4. Does bloody diarrhea always mean a pig has this disease?
No. Bloody diarrhea can occur with many other intestinal diseases. Symptoms, lesions, and laboratory tests should be considered together for an accurate diagnosis.
5. Can the disease be successfully treated?
If detected early, before intestinal damage becomes severe, treatment may be effective. Once piglets have lost a large amount of blood and developed severe intestinal necrosis, the chance of survival is usually low.