Trichodectes spp

From Dog
Adult T. canis[1]

Trichodectes spp are an anoplura parasitic chewing louse of dogs in tropical and subtropical regions across North and South America[2], Asia, India and Africa[3].

These lice have pincer-like tarsal claws for clinging to hairs of their host. They have more than one row of setae per abdominal segment and lack a sternal plate and abdominal spicules. Transmission is between host dogs[4]. Foxes may act as a natural reservoir of infection for these lice.

In tropical urban environments, prevalence rates in dogs can approach 10%[5].

Species which are pathogenic to dogs include:

  • Trichodectes canis

Clinical symptoms are usually limited to superficial dermatitis and secondary self-trauma due to the pruritus associated with lice activity on the coat.

Transmission of Dipylidium caninum occurs, although fleas such as Ctenocephalides spp are far more important vectors.

Diagnosis is made readily on microscopic identification of adults on hair shafts.

T. canis must be differentiated from the anopluran Linognathus setosus and from the warm-climate amblyceran Heterodoxus spiniger.

Treatment is effective with most topical or parenteral macrocyclic lactones such as selamectin, moxidectin, ivermectin as well as other drugs such as imidacloprid[6], milbemycin oxime and insecticidal shampoos[7].


  2. González A et al (2004) Ectoparasitic species from Canis familiaris (Linné) in Buenos Aires province, Argentina. Vet Parasitol 120(1-2):123-129
  3. Omudu EA & Amuta EU (2007) Parasitology and urban livestock farming in nigeria: prevalence of ova in faecal and soil samples and animal ectoparasites in Makurdi. J S Afr Vet Assoc 78(1):40-45
  4. Bowman, DD (2009) georgis' parasitology for veterinarians. 9th edn. Elsevier Saunders, Missouri. pp:34-35
  5. Changbunjong T et al (2009) A survey of ectoparasitic arthropods on domestic animals in Tak Province, Thailand. Southeast Asian J Trop Med Public Health 40(3):435-442
  6. Hanssen I et al (1999) Field study on the insecticidal efficacy of Advantage against natural infestations of dogs with lice. Parasitol Res 85(4):347-348
  7. Mehlhorn H et al (2012) Biting and bloodsucking lice of dogs - treatment by means of a neem seed extract (MiteStop®, Wash Away Dog). Parasitol Res 110(2):769-773