This fact sheet was developed by students enrolled in Purdue's ANSC 442 Sheep Management course in Spring 2001, as a semester project. These fact sheets provide useful information on various topics related to sheep. View the list of fact sheets.


 

 

Overeating 

                       Disease 

What it is: Overeating disease also known as "Enterotoxemia" or "pulpy kidney" disease.  It is a highly significant and costly disease in the sheep industry. This disease is a major killer of lambs from shortly after birth throughout the entire feeding period. Proper preventative practices are strongly recommended to sheep producers to avoid loss of sheep to this disease. Such practices would include proper feeding, management, and immunization.

The word "enterotoxaemia" can be broken down into three parts that can aid in your understanding of the disease.

                                                           entero =  intestine
                                                  tox    =  refers to toxin or poison

                                                emia   =  refers to blood

entero  +   tox   +   emia    = intestinal toxin in the blood


What is  the cause:

Enterotoxemia is caused by the bacterium Clostridium perfringens, Types C and D. Under certain conditions, the bacteria produces toxins that will show signs that will frequently cause animal death.  Clostridium perfringens is found universally in the soil and manure.  It is also present in certain amounts in the intestinal tract of the sheep and most mammals. The bacteria normally inhabits the lower digestive tract and causes no harm to the animal. It thrives on sugars and starches, which are usually digested in the upper portion of the tract. However, when a lamb overeats, not all the starches and sugars are utilized and therefore are passed on. Then the Clostridium perfringens grow and trigger excessive bacterial growth.  This excessive growth allows the bacteria to produce lethal amounts of toxin that are absorbed into the animals system. This occurs when the lamb takes in more than 3/4 pound per head per day.  It can also occur if you allow your feeding lambs to rapidly engorge themselves, or if you feed your lambs during irregular feeding times.  Allowing nursing lambs access to large amounts of milk to consume can also cause an increase in the bacteria's growth.

Type C:  Is thought to be related to milk consumption rather than grain consumption. 

Type D:  Is usually caused by overgrazing or excess grain consumption.

 

 


 

Who it Affects:

 

Type C enterotoxemia affects most often nursing single lambs that have a mother that is a heavy milk producer.  While Type D enterotoxemia mostly will affect weaned and feedlot lambs that are placed on a high energy roughage and grain diet.  It is also common in vigorous, healthy, and rapidly growing lambs.

 


The Signs:

Death is usually the first sign of the disease.  Enterotoxemia progresses very rapidly, with death occurring within two hours after onset of clinical signs.

Some animals will show some symptoms of colic, muscle tremors, or convulsions.  However, the animal may rise between seizures, but soon will collapse again.  Some other nervous system signs are frothing of the mouth, grinding of the teeth, and oscillations of the eyes.  Diarrhea may also be present.  


Diagnosis:

Enterotoxemia must be differentiated from other acute, or fatal diseases, such as blockage, bloat, or acute poisonings. Veterinarians should be called whenever sudden death occurs in lambs of any age. Diagnosis must be determined by careful evaluation of the affected population by first assessing the flock for clinical signs.  It can also be diagnosed by evaluating the management practices, post mortem examinations of the dead lambs, and submission of tissue specimens to a diagnostic laboratory.

Type C: usually shows a discolored, hemorrhagic small intestine

Type D: usually shows a small hemorrhagic spots in the intestines. Fluid around the heart, and lungs is also 

             possible. The animal's urine could also have a high sugar content.

 

***    OTHER CONDITIONS COULD BE FOUND, BUT ARE FOUND LESS OFTEN***

 


Treatment:

Treatment of the animal is usually ineffective, due to the rapid progression of the disease in the animal. The key to treatment therefore, is preventing the disease.  Antitoxins produced by commercial companies can be given either orally or by injection. Administration of antibiotics such as penicillin may be recommended, but is frequently of little value  after clinical signs appear.  

Flock treatments primarily involve a ration change that reduces or eliminates concentrate feeding and increases the amount of roughage fed for a period of time.  The feeding of concentrates should be monitored, and can be gradually increased after the dangers of enterotoxemia have passed.

Prevention:

 

Prevention of the disease is directed toward avoiding rapid proliferation of the organism in the intestinal tract and neutralization of the toxin produced.

 

Vaccination: Type C and D toxoid

                      Requires two injections

                      

The best form of prevention in nursing lambs is by vaccinating with the two-injection vaccine to the pregnant  ewe.  Pregnant ewes should not receive the second booster after four weeks prior to lambing.  The protection comes through the ewes colostrum, and can provide immunity to the lamb up to five weeks of age.

 

      First:  Vaccinate ewes at 6-8 weeks prior to lambing as a first time ewe

                                            In succeeding years vaccinate ewes 2-3 weeks prior to lambing.

 

Second:  Before 4 weeks prior to lambing                                     

 

Vaccination of the lambs may also be necessary to maintain high levels of protection after immunity from colostrum has disappeared.  Repeat vaccination procedure 2-3 weeks in late nursing period.  When early weaning, 40 days, give vaccination about 10 days prior to weaning, and the second 10 days after weaning.  Give late weaned lambs both vaccinations prior to weaning.

 

Prevention and control of the feedlot enterotoxemia can be achieved through management practices. 

Gradual transitions of two to three weeks from roughage to a highly concentrated diet is a must do.  When enterotoxemia breaks out, increase the amount of roughage in the ration for several days, and also the level of chlortetracycline in the feed to about 200 grams per ton for several days.  Also contact your veterinarian. Watching the weather could be detrimental due to lambs loss of appetite in hotter weather, and then eating more when it cools off. Water deprivation will also drastically reduce feed intake, thus when water is reintroduced, sheep will often overeat and have problems.  So a steady source of clean water is very important in preventing the disease. Timing vaccinations, and balancing rations could also help in preventing the disease from occurring.  Such vaccinations should occur as such:

 

First:  Should be administered prior to the feeding period.

 

 Second:  Three weeks later or at least two weeks before 

                starting the lambs on a high concentrate ration. 

 

 

Rams are also administered the vaccination.  They receive a dose annually.

 

 

 

 

Links:
ANSC 442 Home Page
http://www.geocities.com/SoHo/Gallery/5464/index.html