Prevention of Scours
The old adage, "an ounce of prevention is worth a pound of cure," is especially true when dealing with scours. Effective control of scours is accomplished by the application of the sound management practices listed below.
Reduce the exposure of calves to scours causing organisms. This is accomplished by keeping the maternity area clean, dry, and well bedded. Calving areas should be free of animals before the calving period.
Reduce animal densities in maternity and nursing areas. Wash and disinfect the udders of expectant cows before calving. Keep newborn calves, clean, dry, and warm. Clean and sanitize any feeding and treatment equipment. Observe calves for possible health problems several times a day. Isolate sick calves and treat them promptly and thoroughly.
Build up adequate immunity in newborn calves with colostrum. The newborn calf gains immunity to disease by absorbing the antibodies it needs from the gut directly into the blood stream from the mother's colostrum. Maximum immunity to disease is obtained when the calf receives an adequate quantity of a quality colostrum soon after birth. Studies in dairy herds have shown that 60 percent of Holstein calves will not receive adequate immune protection by simply allowing them to nurse. Make sure calves receive at least four to six percent of their body weight in first colostrum within one hour of birth, by bottle feeding. Force feed the colostrum with a stomach tube if the calf refuses to drink. There are several colostrum substitutes that are available commercially. These products are expensive to use and may not provide the calf with the same level of immunity as fresh colostrum from the dam. However they can be a useful alternative when fresh or frozen colostrum is unavailable.
Increase the colostral immunity to scours organisms by vaccination of the pregnant dam. Consult with your veterinarian to develop a comprehensive vaccination program for your herd and area. There are many vaccines available to provide pregnant animals with additional immunity to scours causing bacteria and viruses. These include E. coli, Salmonella, Clostridium perfringens, rota and corona viruses and BVD. Monoclonal antibody products specifically for the K99 strain of E. coli are available. These products come in a paste or tablet form that can be given to calves following birth. The antibodies in these products are absorbed into the blood just like colostral antibodies. However these products only increase the calf's immunity to the strain K99 of E. coli and none of the other scours organisms.
Provide adequate nutrition and sound management to reduce stress. Balance rations to meet animal requirements and maintain adequate body condition in pregnant cows. Feed recommended levels of good quality milk replacers. Feed calves at the same times each day. Provide animals with additional energy in cold weather. Keep sick calves isolated, warm and dry.
To understand the treatment of scours it is important to first understand, "What kills the scouring calf?" The diarrhea is caused by the organism producing toxins, inflammation and damage to the lining of the intestines. No matter what the cause of the diarrhea, the result is that the calf loses tremendous volumes of water and electrolytes in the feces. The dehydration caused by the loss of water and electrolytes is the primary reason most calves die from scours. The other major cause of death is starvation caused by the calf's lack of appetite and the decreased ability of the gut to absorb nutrients. In some cases starvation is caused by the prolonged withholding of milk by farmers in an attempt to treat the disease.
Effective scours treatment must first address the dehydration and starvation caused by the diarrhea. Dehydration is treated by using electrolytes solutions. The clinical signs of mild dehydration include, skin inelasticity, mild depression, a dry mouth, and the calf being unable to stand. Oral electrolytes should be used to treat mild cases of dehydration. Effective commercial electrolyte products that are mixed with water are available from veterinarians and farm supply stores. Also, homemade oral
electrolyte solutions can be mixed from common household products. It is important to follow directions precisely when mixing any oral electrolyte solution.
Oral electrolyte therapy is most successful when given early. Treat scouring calves now, don't wait until the next feeding. Waiting gives the scours organisms a better head start. Electrolytes are not very palatable. When the calf refuses to drink, then the oral solution should be given using a stomach tube. Oral electrolyte solutions should be warm to avoid temperature shock to the calf. Healthy calves should receive 10% of their birth weight in milk or milk replacer per day. Scouring calves lose large quantities of fluid, increase total fluid consumption per day (milk, replacer and electrolytes) up to 20% of birth weight. This can be done by feeding more than two times per day depending on the severity of the dehydration.
One controversial question about the use of oral electrolytes is whether to withhold milk and milk replacers during treatment. Recent research indicates that to avoid starvation, continue to feed milk or replacer at the same rate as usual. Between these normal feedings give the calves the oral electrolyte solutions. Allow 2 to 4 hours between a feeding and treatment with electrolytes. Never mix electrolyte solutions into milk or replacer.
The clinical signs of severe dehydration are severe depression, sunken eyes, cold legs, and failure to stand. Calves with severe dehydration should continue to receive oral electrolytes, but should also be treated with subcutaneous and intravenous fluids. Consult with your veterinarian on the proper techniques and products for these types of treatment.
Oral and injectable antibiotics are commonly used to treat scours. However, they are only effective against bacterial causes of the disease. It is difficult to determine the cause of a specific outbreak without diagnostic cultures and sensitivities. Initially there is little time to submit samples for laboratory analysis. At the onset, sick calves may be blanket treated with an antibiotic based on previous experience. If a response does not occur in 24 to 48 hours, it is unlikely that further treatments with that drug will be beneficial.
It is difficult to learn the cause of a particular case of scours based on the clinical signs alone. Many cases of scours are complicated with several different organisms and similar clinical signs. Also, some strains of bacteria are becoming resistant to commonly used antibiotics. For these reasons, it is important to use your veterinarian to perform examinations and collect the necessary samples for diagnostic analysis. Too often samples are submitted for laboratory analysis too late in the process to save some calves.
Bacterial products are sometimes feed to calves for the prevention and treatment of scours. These products are usually pastes or powders that contain live bacterial cultures. These bacteria are beneficial because they promote a better intestinal environment which makes the calf more resistant to infection. Studies suggest that these products can be beneficial in reducing the incidence and duration of scours.
Work with your veterinarian to develop specific treatment and prevention protocols based on the organisms common in your herd. Put these protocols in writing and make sure they are carried out. Everyone that works with the calves must know what treatments are to be used for the following situations:
- Calf with mild diarrhea, no depression;
- Calf with moderate diarrhea with depression;
- Calf with severe dehydration and depression;
- Calf with diarrhea and respiratory problems.
Finally, accurate health and treatment records should be kept on every animal in the herd. Good records will provide you with the information to make an accurate of diagnosis, determine the effectiveness of treatment and prevention measures and reduce the risk of drug residues.