ACTINOBACILLUS SUIS SEPTICEMIA IN 2 FOALS

A 24-hour-old Hackney pony filly developed signs of weakness, depressi on and a poor suck reflex, with harsh lung sounds over both fields, an d a 48-hour-old Arabian colt from a normal birth which had sucked vigo rously developed loose stools and became depressed, weak and anorectic . Both foals had serum IgG concentrations greater than 800 mg/dl, but each had a severe neutropenia with a left shift, and blood cultures fr om both of them yielded Actintobacillus suis. The A suis isolates had different antimicrobial susceptibility patterns and, in the case of th e Arabian, the isolate was resistant to commonly used broad spectrum a ntimicrobial agents.