Anatrichosoma spp

From Dog
A. cutaneum egg under light microscopy[1]

Anatrichosoma are a parasitic nematode of monkeys[2] and opossums, but has been reported in dogs[3] and cats[4].

Worms normally reside in the squamous epithelium of the nasal cavities. Eggs are sloughed off and are usually swallowed where they are passed into the feces. Aberrant migrations can result in subcutaneous nodules and edema about joints of the extremities, resulting in pododermatitis[5].

Species which are pathogenic include:

  • Anatrichosoma cutaneum

Clinically affected dogs present with raised, flaking, erythematous nodule on the back or limbs.

Diagnosis is based on histopathology of biopsied skin samples, identification of eggs in feces and skin scrapings. These parasites nee to be differentiated from Dirofilaria repens and Dipetalonema spp.

Treatment is usually effective empirically with ivermectin, moxidectin and imidacloprid.

Surgical lumpectomy may be required with large nodules.


  1. Trop Med
  2. Petrzelková KJ et al (2010) Gastrointestinal parasites of the chimpanzee population introduced onto Rubondo Island National Park, Tanzania. Am J Primatol 72(4):307-316
  3. Hendrix CM et al (1987) Anatrichosoma sp infection in a dog. J Am Vet Med Assoc 191(8):984-985
  4. Noden BH et al (2012) Anatrichosoma sp. in the footpads of a cat: Diagnosis and pathology of Namibian case. Vet Parasitol Sep 23
  5. Boeman, DD (2009) Georgis' parasitology for veterinarians. 9th edn. Elsevier Saunders, Missouri. pp:226