Texas Equine Veterinary Association

www.texasequineva.com • 12 supplementation must be added to the fluids to ensure they don't become hypoglycemic. The dextrose supplementation to meet the foal's nutritional requirements for a short-term period should be 8 mg/kg/minute ideally as a constant rate infusion although boluses can be performed but foals may not handle the changes in glucose administration appropriately. Therefore, checking glucose blood levels as often as every 4–6 hours may be important at the beginning as well as starting at a low range and increasing supplementation gradually. If this type of monitoring is required, the foal would definitely benefit from a referral to an institution that is well staffed to perform all the treatments needed. Additionally, a commonly used biomarker in the field for adult horses is serum amyloid A (SAA), which is an acute phase protein of inflammation that has been shown to be helpful in differentiating infectious vs non-infectious conditions. In neonates, the use of SAA has been controversial but there are previous studies suggesting that SAA will be >100 mg/L in foals that have a positive blood culture or evidence of sepsis. (Hulten. C, et al. 2002) This biomarker value can be easily performed stall side but it should be correlated to examination findings. SAA should not replace a white blood cell count but can be used in conjunction with it if desired. Antibiotic therapy is imperative in the neonatal septic foal and it can be the difference between a good and a poor prognosis. For the field veterinarian, if the foal requires antibiotics, then the intravenous route is usually the most preferred way in these young animals. A sterile blood culture should always be collected before starting antibiotic therapy and this can be done at the time of placing an intravenous catheter. The best intravenous catheter option for a neonate is an over-the-wire, although, for plasma administration a short-term catheter is usually sufficient. Antibiotic therapy should be started before blood culture results are available as this may take a couple of days. When thinking about neonatal foal sepsis, the causes are going to vary geographically but the most common isolates include E. coli, Actinobacillus, Enterococcus and Klebsiella. For neonatal foals, the best option is a combination of bactericidal broad-spectrum antibiotics to initiate therapy. Table 4 Antibiotic combinations/ Options Dose, route, frequency Ampicillin + Amikacin 20-40 mg/kg IV TID to QID 20-25 mg/kg IV SID Naxcel (Ceftifour Sodium) 10 mg/kg IV TID to QID Ceftazidime 20-50 mg/kg IV TID to QID Cefpodoxime 10 mg/kg PO TID to QID A common therapeutic approach includes an aminoglycoside if there is no azotemia and a beta-lactam. Ceftiofur can be used at a higher dose to target more gram-negative bacteria if an aminoglycoside cannot be used. A third-generation cephalosporine can also be used as well if kidneys are compromised. Commonly used doses are shown in table 4. If using aminoglycosides, creatinine should be closely monitored every 2–3 days to ensure appropriate kidney function. Another common option once the foal has improved and responded to therapy is Cefpodoxime, a third-generation oral antibiotic when transitioned from IV antibiotics. The antibiotics of choice are influenced by costs, availability, geographical location, and ability to administer at the appropriate frequency. Therefore, this may be a good enough reason to refer a foal for treatment at a 24-hour referral institution if the owner has the financial capabilities. Another factor that becomes very important in these animals is nutrition. Whether the foal is able to handle oral nutrition, needs assistance to nurse, or requires parenteral nutrition, referral should be offered as nutritional care requires special skill and constant monitoring. A foal that is affected by PAS and requires assistance to nurse should be monitored and assisted to nurse every 2 hours. If they cannot nurse, the best way to address this situation is feeding the foal the mare's milk via a nasogastric tube. Bottle feeding is discouraged due to the risk of aspiration pneumonia. If the foal is an orphan and there is no option for a nurse mare, then the foal should be trained to drink milk from a bucket instead. Neonatal foals should ingest 15-20 % of their body weight in milk (BW). Ideally during the first day, they should start at the low end (~5-10%) of BW to ensure that their gastrointestinal tract will handle feedings well, especially in premature foals. Then, this can be gradually increased if well tolerated. One very important consideration when feeding a foal is the possibility of plasma administration following feeding. The neonate should be fed the mare's milk if possible, but there are cases where this is contraindicated such as a positive jaundice foal agglutination (JFA) test or neonatal isoerythrolysis (NI). In these cases, foals are commonly fed a milk replacer if there is no other banked mare's milk available. Plasma should be given before any milk replacer is fed due to the higher chance of a plasma transfusion reaction. Commonly used milk replacers have proteins that are bovine in origin and plasma from equine donors contain anti- bovine antibodies. Therefore, these antibodies react with the bovine proteins and can form immune complexes if the plasma is delivered intravenously after the foal has been exposed to a milk replacer. Finally, neonatal care and diagnostics can be time consuming, and the value of the foal, financial capabilities of the owner should always be kept in mind when determining management options. The veterinarian's initial assessment in the field is very important and referral should always be an option for owners of foals that require frequent and intense care. Talking and discussing with the clinician that will take the case over in the hospital is important as sometimes foals may benefit from stabilization procedures such as fluid boluses and dextrose administration prior to long trailer rides.

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