Source: Pennsylvania State University
Calfhood diarrhea, commonly called scours, is a disease that frequently kills calves and can quickly spread through a herd. It is the most common infectious cause of death in beef calves less than three weeks of age (USDA, 2020). When outbreaks occur in these young calves, it can add tremendous stress to an already busy calving season. A wide variety of pathogens can cause calf scours, including bacteria, like Escherichia coli; viruses; like rotavirus and coronavirus; and even protozoa, like Cryptosporidium. Though they cause diarrhea by different mechanisms, all these pathogens ultimately lead to increased water losses in the feces, resulting in dehydration (Foster & Smith, 2009). Calves with diarrhea will have watery feces that barely sit atop bedding or completely sink into the bedding. It may also cause manure to stain the back end or tail of the calf. In addition to signs of watery feces, calves may also be depressed, uninterested in suckling, have sunken eyes, and may even be unable to rise. When calves do get scours, prompt treatment is critical to prevent death.
Treating the dehydration of calf scours is vital. The severity of dehydration can be estimated by assessing how sunken the calf’s eyes are or by pinching the skin on the shoulder or neck of the calf and assessing how long it takes to return to normal. The more sunken a calf’s eye is, the more severe the dehydration. When the eyeball is sunken by about half a centimeter from normal, it indicates moderate dehydration. In a calf with this level of dehydration, the pinched skin would take 2 to 5 seconds to return to normal (Smith, 2009). Oral fluids, given in addition to milk, are the first line of treatment for dehydration. Choosing an oral electrolyte product with an alkalinizing agent is important because dehydrated calves can quickly become acidotic, which is one of the reasons they stop suckling. Bicarbonate, acetate, and propionate are common alkalinizing agents in oral electrolyte solutions, but acetate and propionate are preferred. These have the advantage of providing energy to the calf, and they do not interfere with milk clotting in the abomasum, an essential step in milk digestion (Smith, 2009). Oral electrolyte feeding, in addition to milk, should be continued until the dehydration is corrected and the feces begin to firm up. When dehydration is severe, oral fluids may not be sufficient. These calves need subcutaneous or intravenous fluid therapy. Sometimes, veterinarians may also recommend anti-inflammatories to manage pain and fever or antibiotics if a bacterial cause or more extensive systemic illness is suspected. Determining how to manage severely ill calves can be done by having the calf examined by a veterinarian, or by working with a vet ahead of calving season to build treatment protocols that will allow prompt treatment without needing emergency veterinary care.
Unfortunately, calf scours can rapidly progress to severe disease and can frequently be deadly. This is why prevention is critical. As with all calfhood diseases, colostrum is vital to disease prevention. All calves should be up and suckling within two hours of birth to receive sufficient colostrum. If calves do not suckle soon after birth, they need to be fed colostrum milked from their dam or a commercial colostrum replacer. Though colostrum replacer products are expensive, they are invaluable to calf health when needed. Scours-targeted oral antibody products can supplement maternal immunity from colostrum. These oral pills or pastes are administered within a few hours of birth to boost calf immunity against scours pathogens. An alternative is to vaccinate cows with a scours vaccine before calving to increase immunity against scours pathogens in natural colostrum. Assuring calves receive colostrum helps to increase their resistance to scours pathogens, but it is also important to decrease their exposure to these pathogens.
Providing plenty of clean, fresh bedding is helpful, but this alone is not enough. Young calves frequently acquire scours from older calves. When a calf gets sick, having an area to separate them and their dam from the main calving or housing areas can reduce the level of pathogens in the main housing area. This, in turn, protects younger calves from exposure to disease. If space allows, setting up multiple calving areas, indoors or out, and moving cows that have not calved to a freshly cleaned pen or unused pasture every couple of weeks can also help reduce exposure between younger and older calves. When preparing for calving season, building a plan to manage calf scours is important. Essential steps to prepare for and prevent scours include:
- Have a good quality colostrum replacer on hand prior to calving season.
- Keep a few packets of oral electrolyte solution with acetate or propionate on the farm.
- Talk with your vet about using a scours vaccine on your dams or an oral antibody product, particularly if scours has been an issue in the past.
- Talk with your vet to build treatment protocols for calf scours so you can manage cases quickly if they arise.
References
USDA. 2020. Beef 2017, “Beef Cow-calf Health and Management Practices in the United States, 2017, report 2.” USDA–APHIS–VS–CEAH–NAHMS. Fort Collins, CO. #.782.1119
Foster, D.M., Geof W. Smith. Pathophysiology of Diarrhea in Calves. Vet Clin North Am Food Anim Pract. 2009 Mar;25(1):13-36, doi: 10.1016/j.cvfa.2008.10.013.
Smith GW. Treatment of calf diarrhea: oral fluid therapy. Vet Clin North Am Food Anim Pract. 2009 Mar;25(1):55-72, vi. doi: 10.1016/j.cvfa.2008.10.006. PMID: 19174283.
