Coccidia - Poultry

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Buff orpington - nabrown RVC
Sporulated Eimeria - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona

Domestic poultry and birds are affected by coccidia called Eimeria. Different species of Eimeria that effect poultry are host-specific – meaning that a species that infects chickens does not infect turkeys and vice versa.

Nine species of Eimeria infect chickens. The species important in broiler production include Eimeria tenella (90%), E. maxima, E. acervulina, and E. mivati; the species important in breeder and egg- layers are E. burnetti and E. necatrix. Seven species infect turkeys – the big three of concern are Eimeria meleagrimitis, E. adenoeides, and E. gallapovonis.

  • Direct life cycle
  • 1 week prepatent period
  • After oocysts are ingested, sporozoites are released which penetrate the intestinal epithelium
  • 2 asexual phases of multiplication called schizogony occur followed by a phase of sexual multiplication called gametogony
  • Zygote develops into an oocyst which is then shed in the faeces
    • Oocyst measures 20-30μm
  • For each oocyst ingested, thousands are shed
  • Life cycle is self-limiting
    • Organisms from a single infection go through the sequence of developmental stages synchronously
    • Organisms leave the body simultaneously as oocysts
  • Oocysts are only infective once they have sporulated
    • Sporulation requires warmth, moisture and oxygen
    • Takes 2-3 days in broiler houses
  • Oocysts contain 4 sporocysts each with 2 sporozoites