Septicemia: Early Detection Is Important

A recently published study could help veterinarians predict the causative agents of a deadly bloodstream infection (septicemia) common in newborn foals by characterizing clinical signs associated with different types of bacteria.

"Infection in the bloodstream is the number one cause of death in foals less than seven days old," explained Kevin Corley, BVM&S, PhD, Dipl. ECEIM, ACVIM, ACVECC, MRCVS, a specialist in internal medicine and critical care at the Anglesey Lodge Equine Hospital in Kildare, Ireland.

In order to treat these foals with effective antibiotics, veterinarians need to be able to quickly identify what types of bacteria are in the bloodstream. It can take several days for laboratory test results to be returned, but treatment decisions are needed much sooner (ideally within 24 hours of initial signs).

During this time, Corley said, "We have to make an educated guess as to what antibiotics to choose to best treat the foal. We know that if we guess right in this early phase of treatment, we have a better chance of saving the foal's life."

In a joint study, researchers at the Royal Veterinary College, North Mymms, and the University of California (UC), Davis, evaluated the records of 85 foals admitted to UC Davis to get a better grasp on how clinical signs and foal history correlated to either Gram-negative, Gram- positive, or a mixture of Gram-negative and Gram-positive bacteria.

"At hospital admission, foals with Gram-negative infections were more likely to be depressed, and foals with Gram-positive infections were more likely to be alert and responsive to stimuli," Corley explained. With Gram-negative infections, "The capillary refill time (an indicator of how well circulation is functioning) was worse (longer), the foal's blood white cell count was lower, and the neutrophils were more likely to show signs of having been activated (indicating toxic changes)."

Mixed bacteria cultures were associated with tachycardia (rapid heart rate), increased serum concentrations of sodium, chloride, and urea nitrogen, acidosis (an increase in total body acid), and respiratory distress.

"We know that choosing the right antibiotic at the start of treatment really improves our chance of successful treatment, decreases the length of time a foal has to be in the hospital, and reduces the expense to the owner," Corley said. "Many things go into the choice of antibiotic, including knowledge of any patterns of resistance to antibiotics in bacteria from horses local to our practice. The best referral hospitals are currently sending home 70-80% of foals with septicemia (that were treated successfully). Any edge we can get in choosing the right antibiotic at the start will help increase this even further."

This study appeared in the January 2007 edition of the Equine Veterinary Journal, p. 84.

About the Author

Chad Mendell

Chad Mendell is the former Managing Editor for .

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