Calf Scours

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Calf Scours

• Causes, Prevention, Treatment
• Brendan Kraus, DVM
• Thanks Dr. Larson

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Calf Scours Complex

• Multifactorial Disease

Host
Environment
Agent
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Host Factors

• Level of Immunity
• Passive Transfer
• Calves are born without antibodies
• Calves should ingest at least 1 gallon of
  colostrum
• in the first 12 hours of life (recommendations
  have changed)
• Many calves ingest inadequate levels

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Host Level of ImmunityPassive Transfer
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Host Level of ImmunityPrevention Tips

• Ensure Adequate Passive Transfer
• Prevent Dystocia
• Bull Selection Based on EPD for birth weight and
  calving ease

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Select for Calving Ease
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Host Level of ImmunityPrevention Tips

• 4) Proper Development of Dam
• Dam should calve at BCS 5.5-6.0
• Avoid over-condition or rapid weight gain in late
  gestation (fat in pelvic canal)

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BCS 6
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Environment Factors

• Overcrowding
• Poor Sanitation
• Damp or wet ground
• Age of Dam
• Poor Quality Milk/milk replacers

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Environment Overcrowding/SanitationPrevention
Tips

• Optimize Environment/Sanitation
• Calving areas should be as clean and dry as
  possible
• Calves should be dispersed as much as possible
  (intensive vs. extensive)

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Intensive vs. Extensive Concentration
Intensive Permits Ready Intervention
Extensive Favors Hygiene
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Environment Overcrowding/SanitationPrevention
Tips

• 1) Optimize Environment/Sanitation (cont.)
• Separate calving pasture from winter feeding
  pastures (more uncommon for spring calvers)
• Feeding strategy considerations

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Feeding Strategy Considerations

• Bale feeders
• Spread bales
• Feed bunk movement
• Water sources
• Stockpiled forage

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Environment Overcrowding/SanitationPrevention
Tips

• Optimize Environment/Sanitation
• 
  (cont.)
• Calving areas should have adequate drainage
• Provide protection from the wind

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Environment Overcrowding/SanitationPrevention
Tips

• Control Exposure
• Which calves are at risk?

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Calves are not Equally at Risk!
1 to 3 week-old calves are also shedding the most
scours pathogens

• Most calves are 1 to 2 weeks of age at time of
  death

• Calves older than 3 weeks are at low risk of
  death

From David Smith et al, 2004
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Calves are not Equally at Risk!

• Calves born early in the calving season are at
  low risk

• Calves born late in the calving season are at
  high risk

From David Smith et al, 2004
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Calves are not Equally at Risk!

• The risk of scours and the severity of disease
  in
• each affected calf increases as the calving
• season progresses
• The age at disease onset decreases as the
• calving season progresses

From David Smith et al, 2004
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Environment Overcrowding/SanitationPrevention
Tips

• 2) Control Exposure (cont.)
• Pasture Rotation
• Keep young calves away from older calves

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Control Exposure Keep Young Calves away from
Older Calves
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Pasture Rotation

• 1) Mid-late gestation pasture (minimum)
• Can be sorted at preg check OR
• 2) Move heavies every 1-3 weeks
• New calves being born on clean pasture
• Older calves staying behind in contamination
• Herd reassembled for breeding
• Youngest calf around 3 weeks old

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Environment Overcrowding/SanitationPrevention
Tips

• 2) Control Exposure (cont.)
• Calve Heifers Early
• Be Wary of Outside Calves

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Agent

• Escherichia coli (1-6 days)
• Clostridium perfringens (1-14 days)
• Rota Virus (5-21 days)
• Corona Virus (5-36 days)
• Cryptosporidium (6-21 days)
• Salmonella (6-36 days)

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E. Coli

• 2 types Septicemia Enterotoxogenic
• Usually within 3-5 days of life
• Severe, watery diarrhea (secretory, ETEC)
• Depression
• Hypothermia
• Distant Infections (joints, brain navel,
  septicemia)

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Enterotoxogenic E-coli
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Clostridium perfringens

• lt 2 weeks old
• Low morbidity High mortality
• Healthy, fast growing calves
• Heavy milking dams
• Sudden Death
• Diarrhea/Abdominal Pain
• Necrosis of small intestine
• Enlargement of intestinal lymph nodes

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Rotavirus

• Most Common
• Often found in mixed infections
• 5 days to 3 weeks of age
• Affects small intestine
• Voluminous (Malabsorptive)
• Lactose washout with osmotic diarrhea
• Dehydration
• At least 7 days to repair intestinal damage

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Coronavirus

• More Severe than Rota
• 5 days to 30 days of age
• Large and small intestine
• Dehydration
• Anorexia
• Infects intestinal cells more severely
• Malabsorption/maldigestion
• Respiratory Infections

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Cryptosporidium

• Zoonotic Potential
• 7 days to 30 days of age
• Protracted, non-responsive diarrhea
• Intracellular but extracytoplasmic
• Drugs difficult to kill
• Off Label

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Salmonella

• gt 10 days of age
• Foul smelling diarrhea
• Fibrin and mucosa may be present in stool
• Distant infections

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Treatment Challenges

• Hypothermia
• Hypoglycemia
• Acidosis
• Low Protein
• Electrolyte Imbalances
• Hypovolemia/Dehydration

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Treatment

• Cornerstone of Treatment is
• Fluid Therapy
• Calculate Dehydration and Replacement Amount

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Fluid Therapy
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Fluid Therapy

• Correct Dehydration
• Correct Electrolyte Imbalances
• Combat Shock
• Support Internal Organ Function
• Supplement Energy

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Fluid Therapy

• Routes of Administration
• Oral
• Intravenous

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Oral Fluids

• Must have GI motility (body temp)
• Must have GI perfusion (dehydration)
• Must have absorptive function (damage)
• Benefits-Inexpensive

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Intravenous Fluids

• Rapid Replacement of fluid deficits
• Replacement of Electrolytes (bicarbonate)
• Base Deficit Correction
• Replacement of Ongoing Losses

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Treatment, Other

• Nutritional Support
• Body Temperature Maintenance
• Maintain Oral Fluids/Electrolytes
• Antibiotics /-

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Scours Outbreak

• Short Term Intervention Strategies
• Treat affected calves
• Calving site selection and management
• Change location of calves
• Calving season
• Move pregnant cows away from nursing cows
• Dystocia management
• Monitor calving closely
• Good husbandry and nutrition of dam

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Scours Outbreak

• Long Term Prevention Strategies
• Care and Nutrition of Dam
• Dystocia
• Sire selection and heifer development
• Calving site selection and management
• Plan ahead, get site ready
• Pasture Rotation
• Be as aggressive as you need for your operation
• Vaccination (last for a reason)

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Scours Vaccination

• Dam vaccinated/antibodies in colostrum
• To be used as a tool in the arsenal
• Usage determined by risk
• Vaccination of younger stock
• Must have two rounds prior to calving the first
  year
• Vaccinations available for the calf
• Will not work as sole prevention measure

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A Too Common Scenario?

• Its March 3, a cold drizzle is coming down as
  you slide across the pasture in 4WD. Vet and
  client are surveying a pasture of 40 cow/calf
  pairs. Calves range in age from 1 day to 2
  months. The mud is ankle deep. Approximately
  50 of the calves have fluid stools. Four calves
  have died in the last 2 days, and at present, 4
  calves are weak and unable to stand. The client
  turns and asks, What do you think we should we
  do?

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Questions?