Rarely does a week go by without a dairy producer asking me what treatment he should use for calf scours. However, before you and your veterinarian can evaluate treatment options, you must examine the calves and conduct laboratory tests to determine the cause, or causes, of the problem.
Identify the bug
The first step in treating calf scours is to take fecal samples from scouring calves. These samples help identify the pathogens causing the scours and dictate the treatment program.
While waiting for laboratory results on the fecal tests, begin supplementing the calf's liquid diet of milk or milk replacer with an electrolyte product (preferably one that contains a buffer) to provide the calf additional fluids and body salts lost from the diarrhea. Wait at least two hours after feeding milk or milk replacer before giving the electrolytes.
Severely-dehydrated animals should be treated with intravenous fluids. Administer hypertonic saline solution with 100 to 200 milliliters of 10 percent dextrose at 2 milliliters per pound of body weight. Always follow up IV treatment with oral fluids.
Once you have the lab results, you can begin treating the specific pathogen affecting your calves. The most common bugs include coccidia, cryptosporidia, viral infections, such as rotavirus and corona virus, and bacterial infections, such as E.coli and salmonella. Treatment should be suited to the pathogen. Review the following recommendations:
Coccidia: Treat calves infected with coccidia with oral sulfa or amprolium for a minimum of 10 to 14 days. Then, switch to a milk replacer that contains a coccidiostat.
Viral Infections: Most infections caused by rotavirus or corona virus can be treated with supportive therapies, such as providing electrolytes or IV treatments. Avoid using electrolytes that have fibrous or mucilin products that artificially "tighten up" a calf's feces. This may mislead you about the calf's recovery.
Vaccinating dry cows with a rotavirus/corona virus vaccine at dry-off and two to three weeks prior to calving can be a key step in preventing this type of scours.
Bacterial infections: Bacterial infections, such as E. coli and salmonella, require aggressive therapy. Providing oral fluid supplementation with intravenous fluids is essential. If calves become toxic, treat with flunixin (sold as Banamine) or Predef 2X.
Your veterinarian might dispense a broad-spectrum antibiotic for bacterial infections; however, this is an extra-label use of the product and must be prescribed. I have had success with trimethoprim/sulfa medications, apramycin or oral spectinomycin. Avoid using gentomycin, as it has a slaughter withdrawal of more than 18 months, and Baytril, as it is not approved in dairy heifers.
Cryptosporidia: This bug is a protozoa and often a secondary pathogen. In my experience, treating the primary cause of scours is the most effective way to deal with cryptosporidia.
Cryptosporidia often indicates problems with the sanitation of calf equipment and facilities. Preventative efforts should start in these areas.
Don't stop with treatment
However, don't settle for just treating calf scours. Work with your veterinarian to implement the procedures needed to prevent calf scours.
First, take blood samples from around 10 to 12 young, healthy calves to gauge the effectiveness of colostrum feeding. The serum from these blood samples can be checked for serum protein - an indicator of immunoglobulin G levels - or sent to a lab to test for specific IgG results.
If inadequate IgG levels exist, focus on improving newborn calf care and colostral management. Check maternity cows frequently, provide newborn calves with quality colostrum and dip navels within hours of birth. Test colostrum quality. And, only feed colostrum from cows that are free from diseases.
Also, review the calves' environment and sanitation procedures for disinfecting bottles, nipples and buckets. Poor procedures in this area can contribute to the pathogen load and spread the problem from calf to calf. Review calf housing to ensure you're providing a clean and dry environment, with adequate ventilation and protection from the elements to minimize stress.
Jim Brett is a practicing veterinarian in Montezuma, Ga.