13. Fluid Administration
It the calf has mild dehydration (5% or less dehydrated), fluids for rehydration can be administered orally or systemically (subcutaneously or intravenously). Fluids should be administered systemically if the calf has moderate or severe dehydration. After determining the administration route for rehydration therapy, decide what type of fluids to use for re-hydration.
Choosing the appropriate fluid for re-hydration is determined according to the estimated osmolality and concentrations of sodium and potassium in the calf's serum. Lactated Ringer's, which best matches the electrolyte content, pH, and osmolality of serum, is the best choice for re-hydration (when analysis of serum electrolytes are not available).
Oral electrolyte solution is an excellent choice if the animal is
less than 8% dehydrated and has a good suckling response.
Electrolyte solutions contain sodium, potassium, chloride, bicarbonate,
glucose, and glycine, and the majority have an alkalinizing
The three calves on this farm are given systemic re-hydration and they perk up somewhat after receiving these replacement fluids. You decide to wait until the culture results are back to determine if antibiotics are necessary. As for the other calves that are ill with scours, it is best not to treat them with antibiotics since they are not depressed or dehydrated. Each calf should be monitored for any changes in clinical signs.
- Can be economically devastating to a producer
- Increased morbidity and mortality of calves
- Decreased growth of calves
- Typically involve opportunistic pathogens
- Opportunistic infections are usually caused by organisms that typically do not cause disease in healthy animals, but affect animals with a suppressed immune system.
- You can rarely diagnose a causative agent without clinical laboratory support.
- Remember that cases, or even health animals, may have two or more opportunistic pathogens diagnosed.
- Use management procedures to prevent disease transmission.
- Handle calves by moving from youngest calves first, and working your way toward the oldest calves.
- Handle calves by moving from healthy calves to sick calves.
- Wear gloves when examining sick calves.
- Locate calf barns away from human and cow traffic.
- Minimize the number of people who go through the calf barn.
- Isolate the sick calves from all other animals.
- Remember that diarrhea typically leads to metabolic acidosis and electrolyte imbalances.
- Types of fluids used:
- If analysis of serum electrolytes is not available, choose a fluid that has similar electrolyte content, pH, and osmolality as does the body’s serum, e.g., lactated Ringer's solution.
- If analysis of serum electrolytes is available, choose the fluid type based on the sodium and potassium concentrations:
- Sodium concentration:
- If sodium is normal, a balanced isotonic electrolyte solution for volume replacement should be used, e.g., NaCl.
- If sodium is decreased, a 0.9% isotonic saline solution should be used.
- If sodium is increased, a 2.5% dextrose in half-strength lactated Ringer's or saline, 0.45% saline, or 5% dextrose in water should be used.
- Potassium concentration
- If potassium is normal, a balanced electrolyte solution should be used, e.g., NaCl.
- If potassium is decreased, lactated Ringer's should be used.
- If potassium is increased, 0.9% saline should be used.
- Routes of administration
- Excellent for mild dehydration (5% dehydrated or less).
- Used to deliver fluids over an extended time for mild dehydration.
- May be used with mild or moderate dehydration (8% dehydrated or less)
- May be used for moderate dehydration (8% dehydrated or less).
- Used for severe or critical dehydration (greater than 8% dehydrated).