Calf Scours Causes, Prevention, & Treatment Brendan Kraus, DVM Thanks Dr. Larson Calf Scours Complex Multifactorial Disease Host Environment Agent Host Factors Level of Immunity Passive Calves Transfer 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 Host: Level of Immunity Passive Transfer Host: Level of Immunity Prevention Tips 1) Ensure Adequate Passive Transfer 2) Prevent Dystocia 3) Bull Selection Based on EPD for birth weight and calving ease Select for Calving Ease Host: Level of Immunity Prevention 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) BCS 6 Environment Factors Overcrowding Poor Sanitation Damp or wet ground Age of Dam Poor Quality Milk/milk replacers Environment: Overcrowding/Sanitation Prevention Tips 1) Optimize Environment/Sanitation Calving areas should be as clean and dry as possible Calves should be dispersed as much as possible (intensive vs. extensive) Intensive vs. Extensive Concentration Intensive Permits Ready Intervention Extensive Favors Hygiene Environment: Overcrowding/Sanitation Prevention Tips 1) Optimize Environment/Sanitation (cont.) Separate calving pasture from winter feeding pastures (more uncommon for spring calvers) Feeding strategy considerations Feeding Strategy Considerations Bale feeders Spread bales Feed bunk movement Water sources Stockpiled forage Environment: Overcrowding/Sanitation Prevention Tips 1) Optimize Environment/Sanitation (cont.) Calving areas should have adequate drainage Provide protection from the wind Environment: Overcrowding/Sanitation Prevention Tips 2) Control Exposure Which calves are at risk? Calves are not Equally at Risk! 1 to 3 week-old calves are also shedding the most scours pathogens Calf Age (days) at Time of Death Due to Scours 50% 40% 30% 20% 10% 0% 0-5 6-10 11-15 16-20 21-25 26-30 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 Calves are not Equally at Risk! Attack Rate by Week (From Start of Calving Season) 30% 25% 20% 15% 10% 5% 0% 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 Calves are not Equally at Risk! Attack Rate by Week (From Start of Calving Season) 30% 25% 20% 15% 10% 5% 0% 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 Environment: Overcrowding/Sanitation Prevention Tips 2) Control Exposure (cont.) Pasture Rotation Keep young calves away from older calves Control Exposure: Keep Young Calves away from Older Calves 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 Environment: Overcrowding/Sanitation Prevention Tips 2) Control Exposure (cont.) Calve Heifers Early Be Wary of Outside Calves 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) 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) Enterotoxogenic E-coli Clostridium perfringens < 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 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 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 Cryptosporidium Zoonotic Potential 7 days to 30 days of age Protracted, non-responsive diarrhea Intracellular but extracytoplasmic Drugs difficult to kill Off Label Salmonella > 10 days of age Foul smelling diarrhea Fibrin and mucosa may be present in stool Distant infections Treatment Challenges Hypothermia Hypoglycemia Acidosis Low Protein Electrolyte Imbalances Hypovolemia/Dehydration Treatment Cornerstone of Treatment is Fluid Therapy Calculate Dehydration % and Replacement Amount Fluid Therapy Fluid Therapy Correct Dehydration Correct Electrolyte Imbalances Combat Shock Support Internal Organ Function Supplement Energy Fluid Therapy Routes of Administration Oral Intravenous Oral Fluids Must have GI motility (body temp) Must have GI perfusion (dehydration) Must have absorptive function (damage) Benefits-Inexpensive Intravenous Fluids Rapid Replacement of fluid deficits Replacement of Electrolytes (bicarbonate) Base Deficit Correction Replacement of Ongoing Losses Treatment, Other Nutritional Support Body Temperature Maintenance Maintain Oral Fluids/Electrolytes Antibiotics +/- Scours Outbreak Short Term Intervention Strategies Treat affected calves Calving site selection and management Calving season Move pregnant cows away from nursing cows Dystocia management Change location of calves Monitor calving closely Good husbandry and nutrition of dam Scours Outbreak Long Term Prevention Strategies Care and Nutrition of Dam Dystocia Calving site selection and management Plan ahead, get site ready Pasture Rotation Sire selection and heifer development Be as aggressive as you need for your operation Vaccination (last for a reason) 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 A Too Common Scenario? It’s 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?” Questions?