Current Progressive Cattle digital edition

Control and prevention of calf scours

Erin Schwandt for Progressive Cattle Published on 24 December 2020
New calf

Newborn calves are most susceptible to developing calf scours, or diarrhea, within the first few weeks of life due to a number of nutrition and environmental factors.

According to the USDA National Animal Health Monitoring System (NAHMS) beef cow-calf study in 2007, approximately one-third (31.4%) of the operations surveyed agreed or strongly agreed that calf scours cause an economic impact on the operation. Digestive problems including bloat, scours, parasites, enterotoxemia and acidosis caused 14% of losses in calves less than 3 weeks old and 22.6% of death loss in calves 3 weeks old or older.

The effect of scours in calves

Calf scours is an enteric disease complex that initially occurs when infectious agents such as Clostridium perfringens, Escherichia coli and Salmonella spp. of bacteria, rotavirus and coronavirus, or protozoan parasites such as cryptosporidia and coccidia are commonly shed in fecal matter by the dam or other calves. These pathogens are easily ingested by calves, proliferate and attack the intestinal epithelium or lining of the calf’s gastrointestinal tract, causing inflammation, or enteritis, and subsequently leading to diarrhea.

Clinical signs of scours are quickly apparent, presenting as watery stools that are brown, yellow, green or gray in color, and may contain blood. Affected calves will appear weak and depressed with a loss of desire to nurse. As their condition progresses, dehydration effects will cause a sunken-eyed appearance and more prominent hips, shoulders and ribs. In addition, calves may appear uncoordinated and stagger as they walk due to low circulating glucose levels and acid-base balance effects of body fluids.

When the intestinal lining becomes inflamed, the ability for the calf to digest and absorb nutrients is impaired and leads to the potential for hypoglycemia, or low blood sugar. In addition, scouring calves quickly lose bodily fluids and are ultimately susceptible to death loss due to dehydration, loss of essential electrolytes and acidosis.

First and foremost, it is important to maintain an ongoing relationship with your veterinarian to develop prevention and treatment protocols, such as a pre-calving vaccination schedule for calf scours as well as other diseases.

It is often recommended that calves displaying any signs affecting their ability to nurse would likely require fluid therapy, or replenishment of water and electrolytes, which provides rehydration, restores the acid-base balance and replaces nutrients in the calf’s bodily fluids.

Factors contributing to scours

Factors influencing prevalence of a scours outbreak is usually attributed to effects on dam nutrition, environment or health status. For instance, cows in a nutrient-deficient state during gestation can have a significant impact on calf vigor and/or produce poor quality and quantity of colostrum. Cows in a tightly confined area or undergoing adverse weather conditions tend to congregate together, creating an area with increased fecal matter and, therefore, greater concentration of scours-causing agents.

Research supports shedding of scours causing infectious pathogens is prevalent in normal, healthy-appearing cattle and was shown to increase with colder weather, in younger cows and heifers, and as pregnant animals approached their calving date.

Prevention strategies for calf scours

One of the biggest factors contributing to a scours outbreak in calves is wet, muddy conditions where the pathogen load is high enough to overcome any antibody protection provided from colostrum and, in these conditions, available nutrients are directed to maintaining homeostasis; thus fewer nutrients are available to fight infections, further putting the calf at risk.

Once a calf becomes infected, the pathogen can quickly replicate, and the calf will shed the infectious agents in the environment to other non-affected calves or even younger, more naïve calves. When possible, it is important to isolate scouring calves and their dam at the first sign of scours to prevent healthy calves and pregnant cows from becoming infected.

Utilizing grass pastures can serve a great benefit

An effective method widely used on ranches throughout the U.S. is the Sandhills Calving System (SCS), developed by researchers at the University of Nebraska – Lincoln. This strategy was used by 40.2% of operations with 200 head or more and utilizes a series of calving pastures to reduce the pathogen load in the pasture as well as the exposure of scour-causing pathogens to the newborn calves.

If the SCS is not an option, be sure to maintain a clean and dry calving environment. Utilizing straw pack, grass pastures or providing shelter to protect calves from snow and other inclement weather can serve a great benefit for optimizing calf survival born in adverse weather conditions. Ideally, a realistic recommended target should be to aim for less than 2% to 3% of calves in the herd developing scours.

Treatment strategies for calf scours

According to NAHMS, over all operations, about four in 10 generally treated calves 7 days old and older for scours with an antibiotic. In addition, of the calves that got sick, approximately 35.4% were due to scours, and approximately two-thirds were treated with an oral (60.7%) or injectable antibiotic (57.4%). Unfortunately, in many of these cases where bacteria were not the cause for scours, antibiotic therapy simply would not help.

Since the implementation of the Veterinary Feed Directive (VFD) in 2017, the FDA has reported a decrease in anti-microbials sold or distributed to the livestock industry by 38% since 2015, indicating ongoing efforts to support anti-microbial stewardship. In addition, there have been significant advancements in research and development of alternative options such as phytogenic feed additives (PFA) to improve preventative and treatment options for animal diseases including scours.

Phytogenic feed additives have been used in animal nutrition, most familiar in monogastrics, for decades but more recently are gaining interest for use in ruminant production applications at calving, receiving and through finishing. Phytogenic feed additives are a combination of the bioactive and flavoring components of plant-derived substances including essential oils, herbs, spices and plant extracts that provide anti-inflammatory, antioxidant and anti-microbial properties, which have been shown to contribute to digestive and gastrointestinal health and performance in cattle.

Across species, gut health-bolstering actions from anti-inflammatory, antioxidative and anti-microbial properties found in licorice extract, oregano and caraway, for example, are perhaps one of the greatest contributions to animal health and performance and contribute toward reducing the severity and long-term effects of diseases such as calf scours.

Phytogenic feed additives are most effective when used as part of a preventative nutrition and animal health program, bolstering the animals’ ability to ward off infection before a problem arises. In the case of acute diarrhea of calves, a rapid intervention PFA application can be applied as a liquid through direct oral application to provide a fast-acting bacteriostatic response for calves. Phytogenic compounds in combination with a readily digestible energy source of medium-chain triglycerides and vitamin E can give a calf a much-needed leg up to take control of the pathogen challenge.


Calf scours is a complex, multifactorial disease affecting baby calves, which has caused a significant economic impact on beef herds in the U.S. Implementing effective and timely control and prevention strategies are key in reducing morbidity and mortality caused by scour-causing infectious pathogens.  end mark

PHOTO 1: Dams in stronger nutritional condition create the right start for calves against a scours environment.

PHOTO 2: Utilizing grass pastures can serve a great benefit toward calf survival. Photos courtesy of Biomin. 

Erin Schwandt
  • Erin Schwandt

  • Ruminant Technical Manager – Beef
  • Biomin America Inc.
  • Email Erin Schwandt