6 Signs of Calf Wellness - Understanding Calf Scours

6 Signs of Calf Wellness - Understanding Calf Scours

Diarrhea is one of the most commonly reported diseases in young calves, and is a major cause of productivity and economic loss to cattle producers all over the world. Multiple pathogens are known to cause and contribute to calf diarrhea.  Other factors that influence the severity of disease include environment and management practices. 


Enteric pathogens colonize and infect the gastrointestinal tract, cause damage to intestinal cells, disrupt nutrient absorption, and result in scours. Calves rarely die from the pathogen themselves, but dehydration and metabolic acidosis caused by the condition.

Identification of the disease pathogen is best determined by sending samples to a Veterinary Diagnostic Laboratory. However, that is not always possible, or may take too long to begin treatment in order to keep calves alive. Bovine veterinarians and cattle producers are aware of many enteric pathogens, because they have been known to be involved in calf diarrhea for several decades. Often the pathogen at large can be identified using the best guess considering age of the calf, and any signs of illness.

Characteristics of each common calf pathogen are described in the chart below. Click on the highlighted pathogen names to watch an informative video about them.


Age of Incidence



Mode of Transition

Bovine Rotavirus

1-2 weeks

-Short incubation period (12-24 hrs.)

-Malabsorptive diarrhea or Drooling saliva.

-Electrolyte therapy



Bovine Coronavirus

5-30 days of age

-Diarrhea for 4-7 days

-High or Low body temperature

-Respiratory Disease Complex

-Electrolyte therapy


Bovine Viral Diarrhea Virus

Newborn Calves



-Low White Blood Cell Count

-Electrolyte Therapy

-Increased   nutrition


-Direct Contact

-Body Secretions



Bovine Torovirus

<3 weeks of age

-Mild malabsorptive Diarrhea

-Refusing to eat

-Electrolyte therapy

-Oral or nasal infection



5-14 days of age

-Acute diarrhea

-Bloody diarrhea

-Systemic Infection

-Refusing to eat

-Electrolyte Therapy

-Antimicrobial therapy as directed by a veterinarian

-Fecal Oral

E. Coli

<5 days of age

-Secretory diarrhea

-Electrolyte therapy

-Antimicrobial therapy as directed by a veterinarian



Clostridium perfringens

5-30 days of age



-Abdominal Pain

-Sudden Death


-Antibiotics under the direction of a veterinarian


-Rapid milk drinking

Cryptosporidium parvum

5-35 days of age


-Severe diarrhea

-Electrolyte therapy

-Fecal Oral





-Light colored scours



-Variation in components, temperature, or mixability


 There are three areas of management when considering disease prevention.

  • Minimize exposure: implement proper cleaning protocols. Areas of concern include; maternity pen, equipment used for calf processing, housing, and feeding equipment.
  • Enhancing immunity: feeding the calf an adequate amount of clean, high quality colostrum as soon as possible after birth. Vaccination of the dam before calving can help to ensure that the colostrum will provide specific antibodies needed to help protect the calf from disease. Additional antibodies and supplements can also be provided to the calf to help enhance immunity.
  • Feed management practices: calves…crave…consistency. Mix milk and milk replacer formulas according to directions provided by the manufacturer and/or your nutritionist. Feed milk at the calves body temperature and on a regular schedule. Ensure that calves are in the correct position to drink to prevent aspiration, and that nipple holes are not enlarged causing milk to flow too quickly for the calf to drink properly. Also, any diet changes should be made gradually.


Written by: Mariah Gull, M.S.

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