Calf Scours: Prevention and Treatment Strategies to Protect Your Young Herd

Calf scours, or diarrhea, is a leading cause of illness and death in young calves. Effective prevention hinges on excellent colostrum management, strict hygiene, and stress reduction. Treatment focuses on immediate rehydration with oral electrolytes, continued milk feeding, and prompt veterinary consultation for severe cases. Early action is key to protecting your valuable herd.

Calf scours can be a devastating problem for cattle producers, often striking young calves during their most vulnerable stage. This common and frustrating challenge leads to dehydration, weakness, and significant economic losses due to treatment costs, reduced growth rates, and even calf mortality. But don’t worry, you’re in the right place to find clear, practical, and effective solutions. This comprehensive guide will walk you through the essential steps for both preventing and treating calf scours, helping you safeguard the health and future of your young herd. Let’s explore how to minimize the impact of this widespread issue with proven strategies.

Understanding Calf Scours: What You Need to Know

Calf scours is more than just diarrhea; it’s a complex syndrome characterized by excessive fluid loss from the calf’s digestive tract. This fluid loss quickly leads to dehydration, electrolyte imbalances, and metabolic acidosis, which can rapidly become life-threatening if not addressed promptly. Understanding the underlying causes and recognizing the symptoms early are critical first steps in effective management.

What Exactly Are Calf Scours?

Simply put, calf scours is diarrhea in young calves. It’s not a single disease but rather a symptom of various underlying issues that disrupt the calf’s digestive system. When a calf has scours, its intestines fail to absorb water and nutrients properly, leading to watery feces. This condition can range from mild to severe, but even mild cases can quickly escalate due to the rapid dehydration young calves experience.

Common Causes of Calf Scours

Calf scours can be caused by infectious agents, nutritional factors, or a combination of both. Identifying the potential cause helps in choosing the right prevention and treatment strategies.

Infectious causes are typically the most common and dangerous. These include:

Bacteria: Such as Escherichia coli (E. coli), Salmonella, and Clostridium perfringens. These often cause severe, sometimes bloody, diarrhea.
Viruses: Rotavirus and Coronavirus are prevalent viral culprits, damaging the intestinal lining and preventing nutrient absorption.
Parasites: Cryptosporidium parvum (Crypto) and Coccidia are microscopic parasites that can cause chronic or severe scours, particularly in slightly older calves.
Mixed Infections: Often, calves are affected by more than one type of pathogen simultaneously, complicating treatment.

Non-infectious (nutritional) causes are also significant:

Overfeeding: Giving too much milk or milk replacer can overwhelm the calf’s digestive system, leading to nutritional scours.
Inconsistent Feeding: Irregular feeding times, sudden changes in milk replacer type, or variations in milk temperature can upset digestion.
Poor Quality Milk Replacer: Low-quality ingredients or improper mixing can lead to digestive upset.
Cold Stress: Calves burn more energy to stay warm, diverting resources from digestion and making them more susceptible to scours.
Poor Sanitation: Dirty feeding equipment, pens, or calving areas significantly increase exposure to pathogens.

Here’s a quick overview of common causes:

Category	Common Pathogens/Factors	Key Characteristics
Bacterial	E. coli (K99), Salmonella, Clostridium perfringens	Rapid onset, severe dehydration, sometimes bloody diarrhea. Often affects very young calves.
Viral	Rotavirus, Coronavirus	Damages intestinal lining, watery diarrhea, less severe dehydration initially but persistent. Affects calves up to several weeks old.
Parasitic	Cryptosporidium parvum, Coccidia	Persistent, watery diarrhea, often yellowish. Can be resistant to some treatments. Affects calves from 1-4 weeks old.
Nutritional/Management	Overfeeding, inconsistent feeding, poor milk replacer, cold stress, poor hygiene	Often milder, can predispose to infectious scours. Correcting management issues resolves it.

Recognizing the Symptoms of Scours

Early detection is paramount for successful treatment. Calves with scours typically show a range of symptoms, starting with changes in their manure and progressing to signs of dehydration.

Watery Feces: The most obvious sign. Feces may range from loose to very watery, sometimes containing mucus or blood. Color can vary (yellow, green, brown, gray).
Dehydration: This is the most dangerous aspect. Look for:
- Sunken Eyes: The eyes appear recessed into the head.
- Skin Tent: Pinch a fold of skin on the calf’s neck. If it stays tented for more than 2-3 seconds, the calf is dehydrated.
- Dry Gums: Gums feel tacky or dry when touched.
- Weakness/Lethargy: The calf may be reluctant to stand, appears listless, or has a weak suckle reflex.
- Reduced Urination: Due to fluid loss.
Loss of Appetite: The calf may refuse to drink milk or milk replacer.
Weight Loss: Rapid weight loss due to fluid and nutrient loss.
Dull Coat: Hair coat may appear rough or dull.
Hypothermia: Scouring calves often struggle to maintain body temperature and may feel cold to the touch.

If you observe any of these symptoms, especially multiple signs of dehydration, immediate action is required.

Comprehensive Prevention Strategies: Building a Resilient Herd

Preventing calf scours is far more effective and cost-efficient than treating it. A robust prevention program focuses on enhancing the calf’s immunity, minimizing exposure to pathogens, and providing an optimal environment.

1. Colostrum Management: The Foundation of Immunity

Colostrum, the first milk produced by the dam, is arguably the single most important factor in preventing calf scours. It provides essential antibodies (immunoglobulins) that protect the newborn calf from diseases until its own immune system matures.

Quality: Colostrum quality varies. Use a colostrometer or Brix refractometer to measure antibody levels. Good quality colostrum has a Brix reading of 22% or higher.
Quantity: A newborn calf needs to consume 10-15% of its body weight in colostrum within the first 12-24 hours of life. For a 90-pound calf, this means 9-13.5 pounds (approximately 1 to 1.5 gallons).
- Aim for at least 2 quarts (2 liters) within the first 2-4 hours.
- Another 2 quarts within the next 6-12 hours.
Timing: The calf’s ability to absorb antibodies decreases rapidly after birth. The “golden window” is within the first 6 hours, with absorption dropping significantly after 12 hours.
Cleanliness: Ensure colostrum is collected and fed in clean containers to prevent bacterial contamination.
Storage: If not fed immediately, colostrum can be refrigerated for up to 24 hours or frozen for up to a year. Thaw frozen colostrum slowly in warm water (not hot) to preserve antibodies.
Supplementation: If the dam’s colostrum quality or quantity is poor, or if the calf fails to nurse, use a high-quality colostrum replacer. A replacer contains a minimum of 100 grams of IgG per dose. Learn more about choosing colostrum replacers.

2. Hygiene and Sanitation: Breaking the Cycle of Infection

A clean environment significantly reduces the pathogen load calves are exposed to, thereby lowering the risk of scours.

Calving Area: Provide a clean, dry, well-bedded calving area. Ideally, use a “calving pasture” system where cows calve in fresh, unused areas, or individual calving pens that are cleaned and disinfected between uses.
Calf Pens/Hutches:
- Individual Housing: Whenever possible, house calves individually to prevent nose-to-nose contact and limit disease spread.
- Clean and Disinfect: After each calf leaves, remove all organic matter, power wash, and disinfect the pen or hutch. Allow it to dry completely before introducing a new calf.
- Bedding: Provide ample, clean, dry bedding (straw works well) to keep calves warm and reduce moisture.
Feeding Equipment:
- Daily Cleaning: All bottles, nipples, buckets, and esophageal feeders must be thoroughly washed with hot, soapy water and disinfected after every feeding.
- Sanitize: Use a bleach solution (1 part bleach to 32 parts water) or a commercial disinfectant, followed by a rinse.
- Dedicated Equipment: Have separate equipment for sick calves to prevent cross-contamination.
Worker Hygiene: Farm workers should wash hands or change gloves between handling sick and healthy calves.

3. Dam Nutrition and Health: A Healthy Start from Conception

The health and nutritional status of the pregnant cow directly impact the vigor and immunity of her calf.

Balanced Diet: Ensure cows receive a balanced diet throughout gestation, with adequate protein, energy, vitamins (especially A and E), and minerals (selenium, copper, zinc).
Body Condition Score (BCS): Cows should be in optimal BCS (around 5-6 on a 9-point scale) at calving. Underfed cows produce weaker calves and poorer quality colostrum.
Vaccination Program: Vaccinate pregnant cows against common scour-causing pathogens (Rotavirus, Coronavirus, E. coli K99, Salmonella) 3-6 weeks before calving. This boosts antibodies in the colostrum, providing passive immunity to the calf. Consult your veterinarian for a tailored vaccination schedule.

4. Stress Reduction: Minimizing Vulnerability

Stress compromises a calf’s immune system, making it more susceptible to disease.

Minimize Mixing: Avoid mixing calves of different ages, as older calves can carry pathogens that younger calves are highly vulnerable to.
Consistent Environment: Provide consistent temperature, ventilation, and feeding routines.
Draft-Free Housing: Protect calves from drafts, especially in cold weather, as cold stress increases energy expenditure and susceptibility to illness.
Proper Ventilation: Ensure good airflow to remove moisture and airborne pathogens without creating drafts.

5. Strategic Vaccination Programs for Calves

While dam vaccination provides passive immunity, direct calf vaccination can also play a role, particularly for pathogens like Salmonella or Coccidia, depending on farm history and risk. Discuss this with your veterinarian.

6. Biosecurity and Herd Health Management

A comprehensive biosecurity plan is essential to prevent the introduction and spread of disease within your herd.

Isolate Sick Calves: Immediately move any calf showing signs of scours to an isolation pen, away from healthy calves.
New Animal Introduction: Quarantine new animals before introducing them to the main herd.
Traffic Control: Limit visitors and vehicles, or ensure proper disinfection if they must enter.
Record Keeping: Maintain detailed records of calf births, treatments, and mortalities. This helps identify patterns, high-risk periods, and effective interventions.

Effective Treatment Strategies: Saving Scouring Calves

Despite the best prevention efforts, some calves may still develop scours. Prompt and appropriate treatment is vital to minimize losses and ensure recovery. The primary goal of treatment is to combat dehydration and electrolyte imbalance.

1. Early Detection and Monitoring

Daily, frequent observation of calves is crucial. Check calves at least twice a day for signs of scours or dehydration. The sooner you intervene, the higher the chance of successful recovery. Pay attention to changes in attitude, appetite, and manure consistency.

2. Fluid and Electrolyte Therapy: The Most Critical Step

Dehydration is the leading cause of death in scouring calves. Replacing lost fluids and electrolytes is the cornerstone of treatment.

Oral Rehydration Solutions (ORS):
- Purpose: ORS provide water, electrolytes (sodium, potassium, chloride), and an energy source (glucose) to help rehydrate the calf and correct metabolic acidosis.
- Timing: Administer ORS as soon as scours are detected, even if the calf is not yet severely dehydrated.
- Frequency: Typically, feed 2-4 quarts of ORS 2-3 times a day, depending on the calf’s size and severity of dehydration.
- Separation from Milk: Do not mix ORS with milk or milk replacer. The electrolytes in ORS can interfere with milk clotting in the abomasum. Feed ORS 2-4 hours after a milk feeding, or 2-4 hours before the next milk feeding.
- Temperature: Administer ORS at body temperature (100-105°F or 38-40°C).
- Administration: For calves with a strong suckle reflex, use a bottle and nipple. For weak calves, use an esophageal feeder carefully to avoid putting fluid into the lungs.
Intravenous (IV) Fluid Therapy:
- When to Use: For severely dehydrated calves (skin tent > 6 seconds, unable to stand, no suckle reflex), oral fluids may not be enough. IV fluids are critical in these cases to rapidly rehydrate and correct severe electrolyte imbalances and acidosis.
- Veterinary Procedure: IV fluid administration requires veterinary expertise. Do not attempt this without proper training and guidance. Your veterinarian can teach you how to administer fluids or perform it themselves.

3. Nutritional Support: Continue Milk Feeding

A common misconception is to withhold milk from scouring calves. However, calves need energy to fight off infection and recover.

Do NOT Withhold Milk: Continue feeding milk or milk replacer. Calves still need the nutrients and energy from milk to maintain their strength and support their immune system.
Reduce Volume (Optional): If the calf is severely scouring, you might temporarily reduce the milk volume per feeding but increase the frequency (e.g., feed half the normal volume twice as often).
Digestible Milk Replacer: Ensure you are using a high-quality, easily digestible milk replacer if not feeding whole milk.

4. Antibiotics: When and How to Use

Antibiotics are only effective against bacterial infections. They are not effective against viral or parasitic scours. Overuse or misuse of antibiotics can lead to antibiotic resistance.

Veterinary Consultation: Always consult your veterinarian before administering antibiotics. They can help diagnose the cause of scours and determine if antibiotics are appropriate.
Systemic Infection: Antibiotics are indicated if the calf shows signs of systemic illness (e.g., fever, lethargy, blood in feces, joint swelling) suggesting a bacterial infection has spread beyond the gut.
Specific Pathogens: If lab tests confirm a bacterial cause like Salmonella or pathogenic E. coli, specific antibiotics may be prescribed.
Follow Directions: If antibiotics are prescribed, administer the full course as directed by your veterinarian.

5. Nursing Care and Supportive Measures

Good nursing care significantly aids recovery.

Warmth: Keep the calf warm and dry. Provide extra bedding, a calf jacket, or a heat lamp (ensure safety to prevent fire). Scouring calves struggle to maintain body temperature.
Clean, Dry Environment: Move the sick calf to a clean, dry, isolated pen with fresh bedding. This prevents further infection and makes the calf more comfortable.
Monitor Progress: Continuously monitor the calf’s hydration status, appetite, and manure consistency. Keep detailed records of treatments given.
Probiotics: Some studies suggest that probiotics can help restore beneficial gut bacteria and improve recovery, though their efficacy can vary. Discuss with your veterinarian.
Anti-inflammatories: Non-steroidal anti-inflammatory drugs (NSAIDs) may be used under veterinary guidance to reduce pain and inflammation, improving the calf’s comfort and appetite.

6. When to Call Your Veterinarian

Don’t hesitate to call your veterinarian. Early intervention by a professional can make a huge difference.

Severe Dehydration: If the calf is severely dehydrated (sunken eyes, skin tent > 6 seconds, unable to stand).
No Improvement: If the calf does not respond to oral rehydration within 12-24 hours.
Bloody Diarrhea: Any presence of blood in the feces.
Fever or Systemic Signs: High fever, extreme lethargy, swollen joints, or other signs of generalized illness.
Multiple Calves Affected: If several calves are scouring, indicating a potential outbreak that needs a herd-level investigation and intervention.
Unsure of Cause: If you’re unsure of the cause or the best course of action.

Here’s a quick guide for treatment steps:

Severity of Scours	Symptoms	Recommended Action
Mild	Slightly loose stool, active, good suckle reflex, no signs of dehydration.	Continue milk. Offer ORS 2-3 hours after milk. Monitor closely.
Moderate	Watery stool, slightly lethargic, mild sunken eyes, skin tent 2-4 seconds. Still has suckle reflex.	Continue milk. Provide 2-3 quarts ORS, 2-3 times daily, separated from milk. Provide warmth.
Severe	Very watery stool, very lethargic, sunken eyes, skin tent > 4 seconds, weak or no suckle reflex, unable to stand.	Immediate Veterinary Attention. Likely requires IV fluids. Continue milk if possible. Provide warmth.

Advanced Considerations and Long-Term Management

Beyond immediate prevention and treatment, adopting a long-term perspective on calf health can significantly reduce future scour outbreaks and improve overall herd productivity.

Understanding Specific Pathogens

While the general principles of prevention and treatment apply, knowing which specific pathogens are affecting your herd can lead to more targeted and effective strategies. Your veterinarian can help with diagnostic testing (fecal samples, post-mortem exams) to identify the culprits.

E. coli (K99): Often affects calves within the first few days of life. Causes profuse, watery, yellow-white diarrhea. Vaccination of the dam is highly effective.
Rotavirus and Coronavirus: Affect calves from a few days to several weeks old. Cause watery diarrhea, often with mucus. Viral scours typically do not respond to antibiotics. Dam vaccination is important.
Cryptosporidium parvum (Crypto): A protozoan parasite that causes persistent, yellowish, watery diarrhea, typically in calves 1-4 weeks old. Highly resistant to disinfectants and difficult to treat effectively. Strict hygiene is paramount.
Coccidia: Another protozoan parasite, usually affecting calves over 3 weeks old. Can cause bloody diarrhea, straining, and poor growth. Preventative medications (coccidiostats) can be used.
Salmonella: A serious bacterial infection that can cause severe, bloody diarrhea, fever, and systemic illness. It can also be zoonotic (transmissible to humans). Requires specific antibiotic treatment and strict biosecurity.

Long-Term Effects of Scours

Even if a calf recovers from scours, there can be long-term consequences:

Reduced Growth Rates: Calves that experience scours often have slower weight gain and may never fully catch up to their healthy counterparts.
Increased Susceptibility to Other Diseases: A weakened immune system post-scours can make calves more prone to respiratory diseases (pneumonia) and other health issues.
Lower Lifetime Productivity: Heifers that had scours as calves may have delayed first calving or reduced milk production in their first lactation.

Economic Impact

The economic impact of calf scours is substantial, encompassing:

Treatment Costs: Veterinary fees, medications, electrolytes, labor.
Mortality Losses: Direct loss of the calf.
Reduced Performance: Slower growth, increased age at first calving, reduced feed efficiency.
Labor Costs: Increased time spent caring for sick calves.

Investing in prevention is almost always more cost-effective than managing outbreaks.

Record Keeping: Your Best Tool for Improvement

Meticulous record keeping is invaluable for identifying patterns, evaluating prevention strategies, and making informed management decisions.

Individual Calf Records: Date of birth, dam ID, colostrum intake, vaccination history, dates of illness, symptoms, treatments given, and outcome.
Herd-Level Data: Track the incidence of scours, mortality rates, and the effectiveness of different prevention or treatment protocols.
Veterinary Consultation: Share your records with your veterinarian. They can help analyze the data and fine-tune your herd health program.

By integrating these advanced considerations into your calf management program, you can move beyond simply reacting to scours and proactively build a healthier, more productive young herd. Protecting your calves from scours is an ongoing commitment that pays significant dividends in the long run.

Frequently Asked Questions About Calf Scours

Q1: What is the main cause of calf scours?

Calf scours is primarily caused by infectious agents like bacteria (e.g., E. coli, Salmonella), viruses (e.g., Rotavirus, Coronavirus), and parasites (e.g., Cryptosporidium, Coccidia). However, poor management practices such as inadequate colostrum intake, poor hygiene, overfeeding, and cold stress significantly increase a calf’s susceptibility to these infections.

Q2: How do I know if my calf has scours?

The most obvious sign is watery or very loose feces. Other key symptoms include dehydration (sunken eyes, skin that stays tented when pinched), weakness, lethargy, loss of appetite, and a dull hair coat. Calves may also appear cold or struggle to stand.

Q3: What is the most important thing to do for a scouring calf?

The most critical step is to provide immediate fluid and electrolyte therapy using an oral rehydration solution (ORS). Dehydration is the leading cause of death in scouring calves, so replacing lost fluids and electrolytes is paramount. Continue feeding milk or milk replacer, but separate it from ORS feedings.

Q4: Can I give a scouring calf milk? Should I stop feeding milk?

No, you should NOT stop feeding milk or milk replacer. Scouring calves still need the energy and nutrients from milk to maintain their strength, support their immune system, and recover. The common misconception to withhold milk can actually worsen the calf’s condition. Just remember to feed oral rehydration solutions (ORS) at separate times, typically 2-4 hours apart from milk feedings.

Q5: When should I call the vet for calf scours?

You should call your veterinarian immediately if a calf is severely dehydrated (unable to stand, no suckle reflex, very sunken eyes), shows no improvement after 12-24 hours of oral rehydration, has bloody diarrhea, develops a high fever, or if multiple calves are affected. Early veterinary intervention can significantly improve outcomes.

Q6: How can I prevent scours in newborn calves?

Prevention is key! Focus on excellent colostrum management (ensuring calves get enough high-quality colostrum quickly after birth), strict hygiene and sanitation in calving areas and calf pens, providing a clean and dry environment, ensuring proper nutrition for the dam, and considering a dam vaccination program against common scour pathogens. Minimizing stress for calves is also important.

Q7: Is scours contagious to other calves?

Yes, most causes of calf scours are highly contagious. Viral and bacterial pathogens can easily spread through direct contact, contaminated feeding equipment, or shared environments. This is why strict hygiene, individual housing, and immediate isolation of sick calves are crucial to prevent widespread outbreaks within your herd.