From Dog
Heterodoxus longitarsus adult under light microscopy[1]

Lice (Order: Phthiraptera) are ectoparasites represented by the suborders Anoplura (blood sucking) and the Mallophagans suborders including Ischnocera, Amblycera and Rhychophthirina (chewing lice)[2].

  • Anoplurans - piercing mouth parts with three stylets within a fixed narrow head. Parasites of placental animals only
  • Mallophagans - stout mandibles on the ventral side of a broad head. Feed on epidermal scales, feathers and sebaceous secretions of birds and mammals.

Lice are dorsoventrally flattened, wingless insects that live close to the skin, and spend their entire lives among the hair of dogs and have a high order of host specificity. Adult females lay eggs which, when hatched, are miniature replicas of adults. Immature stages undergo a number of molts (simple metamorphosis), with 2 weeks required for the life cycle from egg to adult.

Increased numbers of lice correlate significantly with dog crowding pressures, poor nutrition and inclement weather.

Common lice found on dogs include:

Species Suborder Common name Geographical distribution
Heterodoxus spiniger Amblycera chewing louse Worldwide
Linognathus setosus Anoplura biting louse Worldwide
Trichodectes canis Ischnocera chewing louse Worldwide


  1. Foter
  2. Bowman, DD (2009) Georgis' parasitology for veterinarians. 9th edn. Elsevier Saunders, Missouri. pp:33