Linguatula serrata

Copyright Cooper Curtice (Washington, Government Printing Office, 1890) Wikimedia Commons
  • Also known as the tongue worm


Recognition

  • Tongue-like appearance
    • Expanded anteriorly
  • Adults are over 10cm in length
    • Females measure between 30-130mm in length
    • Males measure up to 20mm in length
  • Transversely striated


Life cycle

  • Life cycle takes 6 months
  • Eggs are expelled by coughing and sneezing or are passed out with the faeces
  • Herbivorous intermediate hosts ingest the eggs
  • Larvae migrate to the mesenteric lymph nodes and encyst to become infective nymphs
    • Cysts measure 1mm in diameter
  • When a dog eats infected uncooked viscera the life cycle is completed
  • Infective nymphs mature to adults in the nasal cavities and can survive for a year in the final host

Pathogenesis

  • Heavy infection leads to coughing, sneezing and nasal discharge


  • Synonym: tongue worm
  • In nasal passages of dogs, sometimes cats
  • May reach the sinuses
  • Heavy infections may cause sneezing, coughing, nasal discharge