Causative agent
- Trypanosoma evansi


Differential diagnosis
- Equine infectious anemia
- Strangles
- Ehrlichiosis
- Worm infection
- Meningitis


1. History taking
- High mortality rate
- Sudden death
- High density of horse fly (Tabanus sp.) and
  stable fly (Stomoxy sp.) population in the farm
- Outbreak often occurs after rainy season
- Cattle raising area nearby


2. Clinical examination
- Disease may be acute or chronic
- Pyrexia
- Urticarial eruption of the skin
- Anemia to jaundice
- Edema on the ventral surface of the body
- Reluctant to walk
- Chronic case may show nervous signs such as
  cycling


3. Microscopic examination
- Demonstration of trypanosomes in blood
  using wet blood film, thick and thin blood
  smears
- Hematocrit centrifuge technique (HCT)
- Quantitative buffy coat technique (QBC)
- Trypanosomes are best demonstrated in early
  infections and in acute stage

4. Experimental animal inoculation
- Inoculate suspected blood samples into
  laboratory rodents


5. Serological tests
- Card agglutination test
- IFAT
- ELISA


6. Necropsy
- Patchy alopecia
- Petechiae and ecchymoses of visible mucosae
- Splenomegaly
- Enlargement of lymph nodes and liver
- Pale and flabby myocardium


7. Histopathological observation
- Lymphoid hyperplasia in spleen and lymph
  nodes
- Accumulation of lymphohistiocytic cells in
  liver
- Nonsupurative myocarditis
- Hemosiderosis is evident in phagocytic cells
  of spleen, lymph nodes, liver and lung


Control and treatment
- Whole herd treatment with trypanocidal drugs;
  such as Isometamidium chloride (Samorin^R),
  or diminazene aceturate (Berenil^R) on the
  positive farm
- Preventive control with trypanocidal drugs
  before and after fly season
- Fly control by regular application of effective
  insecticides on animals