Staphylococcus hyicus

Exudative epidermitis (Greasy pig disease)

• Worldwide disease of pigs under 3 months of age caused by S. hyicus
• Highly contagious and persists in the environment for long periods
• S. hyicus produces exfoliative toxin that causes separation of cells in stratum spinosum resulting in rapid intraepidermal spread of organisms
• Similar to “scalded skin syndrome” in human neonates, due to skin infection by exfoliative toxin-producing Staphylococcus aureus
• Excessive sebacious secretion and exudation on surface of skin
• Pigs are anorexic, febrile, depressed and have a greasy, non-pruritic dermatitis
• SKin thickened, wrinkled and scaley
• Acute death in piglets under 3 weeks due to dehydration and septicaemia
• 20-100% morbidity; up to 90% mortality
• Organism enters skin via abrasions e.g. bite wounds
• Carried in vaginal mucosa and skin of sows
• Predisposed by lack of milk, weaning and other infections
• Piglets from non-immune sows are predisposed
• Passive transfer of antibodies from immune sows and development of immunity with age protect against disease
• Isolation from skin lesions
• Early systemic antibiotics amd topical antiseptics/antibiotics useful
• Disinfection after outbreak
• Wash sows before farrowing
• Differential diagnosis:
  • Mange (Sarcoptes scabiei var. suis)
  • Swine parakeratosis (zinc and essential fatty acid deficiency)
  • Porcine juvenile pustular psoriasiform dermatitis (collarettes or rings typically on the ventrum of young pigs)
  • Dermatosis vegetans (associated with a giant cell pneumonia)
  • Dermatophytosis (most commonly Microsporum nanum)