Percent calves born dead, died, or were lost during 1996 NAHMS Beef ’97 Study Born dead 24 hrs or less 24 hrs – 3 wks 3 wks – weaning

Calf Age and Organism OrganismApproximate Calf Age E. coliDay 1 (days 1-7) RotavirusDay 4-9 (days 1-14 up to 5 wks) CoronavirusDay 5-9 (days 2-14 up to 6 wks) Clostridium perfringensDay 1-2 (days 1-7 & weeks 4-6) Cryptosporidium parvumDay 7-10 (days 7-21) Salmonella spp.Day 7-21 (day 7 through 4 mo.) CoccidiaDay 21 and up Most of the time it is a mixed infection!

Disease prevention

Animal - nutrition, immune system, etc. Environment - temperature, mud, etc. Agent- virulence, exposure, etc. Increase resistance Prevent transmission Remove agent

Prevention Recreate early calving season conditions – “Clean” calving area – Absence of older calves Goal: Reduce/prevent transmission

Weeks 1&2

Week 3

Week 4

Week 5

Week 6

Week 7

Week 8

Week 9

Pathogenesis Diarrhea Dehydration and Lactic Acidosis Hypovolemic Shock Decreased Profusion Ischemic Damage of Multiple Organs Translocation of Enteric Bacteria Septicemic Shock Death

Treatment of Neonatal Diarrhea Dehydration Acid/Base Imbalance Electrolyte Abnormalities Hypoglycemia Ancillary treatments – Antibiotics – NSAID’s

Rehydration Therapy Route Volume Composition Duration ?

% Dehydration Eyeball Status Skin Tent (in seconds) Mucus membranes 0None<1Moist 1-5None to Slight1-4Moist 6-8Slight Separation 5-10Tacky 9-10<5 mm gap11-15Tacky to dry mm gap16-45Dry Compiled from Howard, Smith, Blood et. al.

Daily Fluid Requirement: Replacement = % dehydration x body wt. Maintenance = 50 mL/kg/day or 1mL/#/hr Estimated loss to diarrhea = 1-4 L/day

Acid-Base Assessment Naylor

Electrolytes and Energy Serum Chemistry – Potassium Hyperkalemia Total body depletion of K – Sodium – normal to low normal – Chloride – normal to low normal Negative energy balance – Hypoglycemia – Do not give oral table sugar (sucrose)

Intravenous Fluid Therapy Options 0.9% Saline Ringer’s solution Lactated Ringer’s solution Isotonic sodium bicarbonate Supplemental 5% Bicarb Others

Calculation of Replacement Bicarbonate Normal venous blood pH = 7.34 Normal serum bicarbonate values for calves = 30 mmol/L with a base excess of 5 mmol/L Constant for volume of distribution= 0.6 Body wt in kg X (30-TCO2) X 0.6 = mEq of bicarb needed Acid-base correction – HCO3 - or bicarb equivalent like acetate, citrate, or L-lactate Commercial sources of Bicarb 8.4% - supplies 1mEq/ml 5% - supplies 0.6mEq/ml

Other Intravenous Fluid Considerations Ion replacement – Na +, K +, Cl - – mEq/liter of fluids – Do not exceed 0.5 mEq/kg/hour Energy maintenance

Ancillary Tx Antimicrobials – Bacteremia – Control intercurrent infections – Prevent iatrogenic infections Flunixin meglumine – Correct dehydration first!

Questions?