Enterotoxemia, also known as overeating or pulpy kidney disease, is a condition caused by Clostridium perfringens type D. These bacteria are normally found in the soil and as part of the normal microflora in the gastrointestinal tract of healthy sheep and goats. Under specific conditions, these bacteria can rapidly reproduce in the animal’s intestine, producing large quantities of toxins. The epsilon toxin produced by C. perfringens Type D is the most significant toxin in producing the disease. Young animals are most susceptible. Sudden and high mortality rates may occasionally occur in lambs and kids. Although adult animals are also susceptible to enterotoxemia, they develop immunity due to frequent exposure to low doses of these toxins.
Factors Associated with Enterotoxemia Outbreaks
Overgrowth of Clostridium perfringens type D in the intestine of sheep and goats resulting in enterotoxemia are more likely to occur during the following conditions:
- Excessive consumption of milk or feed with high concentrations of grain
- When natural immunity is compromised such as when ill, recovering from an illness or stressed
- When animals are heavily parasitized with gastrointestinal parasites, including nematodes, cestodes (tapeworms) and coccidia
- When the ration is rich in carbohydrates (grains) and low in roughage
- When motility of the gastrointestinal tract is reduced
Common Signs of Enterotoxemia
The peracute form is most frequent in young animals. It is characterized by sudden death that occurs approximately 12 hours after the first signs of the disease appear. Some kids or lambs may show signs of central nervous disease, such as excitement or convulsions. Sudden death may occur in only minutes in kids or lambs showing neurological disease. Typical clinical signs include:
- Loss of appetite
- Abdominal discomfort
- Profuse and/or watery diarrhea that may be bloody
Diagnosis is based on clinical signs, history of sudden death and confirmation by necropsy examination. Diagnosis can be confirmed by positive identification of enterocolitis, anaerobic culture, and identification of Clostridium perfringens type D from the feces or intestinal contents from clinical or necropsy specimens of affected animals. The presence of hyperglycemia and glucosuria can strongly suggest enterotoxemia in live or dead animals. Necropsy data is important for the diagnosis of enterotoxemia. Therefore, dead animals or a complete set of necropsy tissues, feces, etc., should be submitted to the diagnostic laboratory for confirmation of the clinical diagnosis. A postmortem examination of the large and small intestines can identify watery contents, blood and fibrinous clots, and small ulcers on the mucosa. The kidneys on gross examination may have a soft pulpy consistency and encephalomalacia may occur within the brain (usually only seen in sheep). On microscopic examination there may be accelerated autolysis or diffuse acute necrosis of the proximal tubules in the kidney. Microscopic ulcers and superficial mucosal necrosis with numerous associated clostridial organisms and mild suppurative inflammation may be present in intestinal specimens. Intestinal lumens will often contain abundant clostridial organisms suggesting clostridial enteritis/enterotoxemia. Advanced postmortem autolysis often prevents definitive diagnosis of enterotoxemia at necropsy due to the extensive overgrowth of clostridial organisms after death of the animal. Specific DNA testing assays (PCR) for Clostridium perfringens type D may be useful for confirmation of the diagnosis. An ELISA kit is also available for the detection of several clostridial toxins including the epsilon toxin and identification of the C. perfringens organism itself from intestinal contents.
Recommended treatments can include the following:
- Clostridium perfringens C & D antitoxin according to the manufacturer’s recommendations (5 mL of C & D antitoxin subcutaneously)
- Antibiotics, especially penicillin
- Orally administered antacids
- Anti-bloating medication
- Pain reduction
- Intramuscular thiamine (vitamin B1) to prevent or treat the encephalomalacia
- Supportive therapy such as intravenous or subcutaneous fluids and corticosteroids
- Probiotics after antibiotic therapy to encourage repopulation of the microflora in the GI tract
Effective vaccines are commercially available to prevent enterotoxemia in sheep and goats. All animals (especially young animals) within the herd should be vaccinated as it will reduce the chances that the animals will develop the disease. Use vaccines that are labeled for use in sheep and goats and follow the manufacturer’s recommendations. Some of the commercially available vaccines against enterotoxemia are also combined with tetanus toxoid. Make sure the vaccine has been refrigerated, stored properly, and is not expired. Young animals should be vaccinated at 4 weeks of age and again one month later. All adults including bucks should be vaccinated at least once per year. Do not vaccinate animals that appear ill and keep good vaccination records for future reference.