Hepatozoon americanum (Canine American Hepatozoonosis) - Microscopic exam; Molecular diagnosis (PCR)


Hepatozoon americanum is protozoan parasite of dogs, Hepatozoon gender, family Hepatozoidae. Hepatozoon americanum is located in geographic areas with tropical and subtropical climates, although it has a strong presence in the US In animals, infection with this parasite causes the American Canine hepatozoonosis. The disease is caused by the difference Hepatozoon canis as clinical signs, tissue tropism and in morphological and pathological findings. In addition between the two protozoa they are antigenic and its 18S rRNA differences.

The life cycle of this organism involves a vertebrate host intermediary (dogs and other canids), and a definitive host invertebrate, mainly ticks Amblyomma maculatum species. Sexual reproduction and development sporogenic occur in the invertebrate host, which is then ingested by the vertebrate host. Dogs become infected by ingesting a tick containing oocysts with sporozoites. Once in the body of the vertebrate host, the sporozoites traverse the intestinal epithelium of the animal, which migrate to the liver and multiply by multiple fission in merogonia asexual multiplication, which occurs mainly in striated muscle, resulting in merozoites. Here are released into the bloodstream where they transform into gametocytes, the final phase of development in the vertebrate host. When the invertebrate vector feeds on the blood of infected vertebrate, gametocytes present in their neutrophils or monocytes are absorbed in the gut of the invertebrate host, resulting in gametogenesis, which after fertilization of the macrogamete by microgamete will result one zygote that will become oocyst, the sporozoites and it will appear.

Hepatozoon americanum infection differs from Hepatozoon canis infection, as clinical signs, tissue tropism and morphological and pathological findings. The infection causes a debilitating and often fatal disease. Generally it manifested by periodic or persistent fever, weakness, muscle atrophy, stiff gait, generalized or hyperesthesia pain, eye mucopurulent discharge, anemia, and gradual deterioration of condition.

Recommended tests for diagnosis:


The diagnosis is based on microscopic observation of the parasite in peripheral blood smears or extensions prepared from the buffy coat, detection of antibodies by indirect immunofluorescence methods or ELISA, either in molecular diagnostic methods (PCR). The molecular diagnostic tests Hepatozoon canis and differentiate Hepatozoon americanum.

Tests in IVAMI:


  • , Preferable from the buffy coat (buffy coat). Microscopic examination
  • Molecular diagnosis (PCR), to detect DNA americanum Hepatozoon canis and differentiate Hepatozoon.

Recommended sample:


  • Whole blood collected with EDTA (2 to 5 mL).


Preservation and shipment of sample:


  • Refrigerated (preferred) for less than 2 days.
  • Frozen: over 2 days (for molecular diagnostic tests only).


Delivery term:


  • Microscopic examination: 24 hours.
  • Molecular diagnosis (PCR): 24 to 48 hours.

Cost of the test:


Consult ivami@ivami.com