Equine: Parasite Diagnostic Terms

Single-cell Embryo = Fertilized egg (zygote) prior to cell division.

Morulated = Zygote has gone through a few cell divisions.

Embryonated = Multi-cellular embryo at the tissue / organ development stage, prior to taking final form.

Larvated = Near completion of development, with organism taking final form prior to hatching. May be active within the shell.

Operculum or Plug = A thick cap from which worms hatch from the egg.

Hexacanth = Fully developed larval stage possessing 3 pairs of hooklets. May also be called an Onchosphere. A term specific for eggs of Tapeworms.