Coccidiosis - Sheep

• 11 different Coccidia species although only two are of clinical significance
  • Giant schizonts visible as white spots

• Eimeria ovinoidalis
  • Highly pathogenic
  • Diarrhoea
  • Parasitises the caecum and colon

• Eimeria crandalis
  • Varying pathogenicity
  • Scours, grey, foul-smelling faeces
  • Parasitises the small intestine, caecum and colon

• 2 week prepatent period

• Disease frequently seen in lambs under 6 months old
  • More often in twins and triplets when single lambs

• Oocyts from ewes (immune carriers) accumulate in poorly managed litter or around feed and water troughs

• Lambs born early in the year amplify the parasite problem increasing the parasite risk to lambs born later in the year

• Affected lambs may die before oocysts are found in the faeces
  • Post-mortem diagnosis difficult

• Different species of Eimeria occurs in sheep and goats

• Infection may be coincident with Neospora or Cryptosporidium infections
  • Mixed infections complicate the diagnosis as oocyst differentiation is difficult

• Other non-pathogenic species can cause papillomatous mucosal growths

Control

• Improve husbandry
  • Avoid overcrowding
  • Decrease stress

• Improve hygiene by dagging ewes

• Avoid mixing lambs of different ages

• Preventative measures include creep feeding lambs with decoquinate or oral dosing with diclazuril when lambs are 4-6 weeks
  • A second dose can be given after 3 weeks