Synulox Bolus 500 mg film-coated tablet Uses Synulox boluses have a notably broad spectrum of bactericidal activity against bacteria commonly found in calves. In vitro Synulox is active against a wide range of clinically important bacteria including: Gram-positive: Staphylococci (including β-lactamase producing strains); Streptococci; Corynebacteria; Clostridia; Actinomyces bovis. Gram-negative: Escherichia coli (including β-lactamase producing strains); Salmonellae (including β-lactamase producing strains); Klebsiellae; Proteus spp.; Pasteurellae; Fusobacterium spp.; Haemophilus spp. The clinical indications for Synulox boluses are in the treatment of enteritis and navel ill in calves.