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Equine neonatal sepsis: treatment (Proceedings)

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Aug 01, 2011

Treatment of failure of passive transfer (fpt)

     A. If the foal is less than 12 hours, it can be given 1-3 liters of high quality (sp gr > 1.090) colostrum. (Frozen colostrum should be thawed in warm water, rather than the microwave. Ideally colostrum should be < 12 months old). Serum or plasma is too low in IgG to be of benefit given orally. Bovine colostrum can be given, but it is not nearly as good as equine colostrum.
     B. Intravenous IgG- concentrated serum products have a higher risk of anaphylaxis because they are made from multiple donors. After plasma or serum administration, IgG concentration should be rechecked 12-24 hours later. More should be administered if IgG is < 400 mg/dl. Most foals will receive 1-2 L of plasma; however, large foals with an IgG concentration <200 mg/dl will usually require 3L. As a foal's blood volume is ~ 10% of body weight, and whole blood is 2/3 plasma, the plasma volume of a 45 kg (100lb) foal is: 4.5 liters x 0.666 = 3 liters. Therefore a maximum of 1 liter of plasma should be given to a 40-60 kg foal per day. If necessary, the second liter can be administered the following day. Septic foals can consume or leak IgG and IgG should be reassessed every few days. Septic foals often benefit from additional plasma transfusions.

Sepsis therapy

Should begin as soon as disease is suspected; don't wait until disease is confirmed!
          1. Broad-spectrum antimicrobials. Intravenous penicillin and an aminoglycoside (gentamicin or amikacin) are commonly given. Treatment should be long-term (at least 10 days) to prevent localization. Localized infection should be treated for at least 21 days to prevent recrudescence.
          2. Plasma, if there is failure of passive transfer. Most clinicians believe that intravenous plasma therapy is a valuable treatment even for septicemic foals that have adequate IgG concentration.
          3. Fluid therapy. Intravenous isotonic fluids with added glucose. 3-5% at shock rates or 5-10% dextrose at maintenance rates. Immediately revives some comatose, septicemic foals. Intravenous balanced electrolyte solutions are often bloused at periodic intervals. If IV fluids are required > 24 hrs then a maintenance fluid (or mix of 5% glucose and a balanced isotonic replacement fluid) should be given. Replacement fluids are high in sodium and foals are designed to live on a low sodium milk diet. There kidneys have difficulty excreting the excess sodium, so hypernatremia can become an issue. Maintenance fluids have lower sodium and higher potassium concentrations.
          4. Good nursing care – nutritional support (enteral or parenteral)
          5. Monitor – cardinal signs, PCV, TP, electrolyte levels, blood glucose and presence of glycosuria must be regularly checked and foal checked regularly for development of any localizing signs.