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Ancylostoma braziliense Homepage

        Common name: Hookworm

          Kingdom: Animalia

            Phylum: Nematoda

              Class: Secernentea

                Order: Strongylida

                  Superfamily: Ancylostomatoidea

                    Genus : Ancylostoma

                      Species: braziliense

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Adult Parasite:

    Males measure 7.5 to 8.5 mm. Females measure 9 to 10.5 mm. The buccal capsule has one pair of small medium teeth and one of larger outer teeth.


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  • Definitive: dog (Canis Familiaris), Cat (Felis catus).

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Life Cycle:

    Anclystoma braziliense follows the same developmental pattern of human and canine hookworms. Separate strains occur in cats and dogs. Eggs are passed in feces. Larvae develop in soil to the L3 infective stage and then are ingested by the host or they enter the host through cutaneous contact and then the larvae migrate to the lungs, and then on to the intestinal tract of the host. In the intestinal tract, the larvae develop into adults.  Eggs are then expelled in feces and the cycle continues.

    NOTE: The canine and feline strains of A. braziliense are unable to to penetrate the subdermal layers of the skin of man. When man is exposed to the infective larvae, the larvae tunnel through the skin creating a lesion that is at first inflamed and then elevated and vesicular, and finally dry and crusted. The larvae may tunnel through the skin for weeks but rarely reach the circulation, thus humans are a "dead end host" of A. braziliense.

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Site where adult parasite is found in host:

  • Small intestine

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Diagnostic Stage:

  • Eggs are found in fecal flotation.
  • Eggs are 60 x 40 um.
  • L1 larvae are occasionally found in older feces (over 24 hours old) and are diagnostic of infection.


Ancylostoma braziliense eggs (left), L1 larvae (middle), diagram of L1 larvae (right).

Common Diagnostic Test

Clinical Signs:
  • Puppies and kittens: Anemia, diarrhea, weight loss, weakness, poor growth, occasionally death.
  • Adults: Usually asymptomatic but any of the above symptoms may be present.


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University of Pennsylvania  2004

Comments or Questions please contact:  Dr. Nolan at: