Causative agents
- Acute coccidiosis (cecum) : Eimeria tenella
- Acute coccidiosis (small intestine) : E. necatrix,
  E. brunetti
- Chronic coccidiosis : E. maxima, E. acervulina
  E. mivati, E. praecox (minor pathogen)


Differential diagnosis
- Bacterial and viral enteritis


1. History taking
- Widely distributed throughout the country
- Intensive animal-rearing and husbandry
- Decreased feed and water consumption, and egg
  production
- Increased mortality
- High percentage of visibly sick birds


2. Clinical examination
1. Acute cecal coccidiosis
- bloody diarrhea on day 4 or 5 after infection
- anemia
- lethargy and death
2. Acute small intestinal coccidiosis
- similar clinical signs as cecal coccidiosis
- high mortality
3. Chronic coccidiosis
- indigested or watery diarrhea
- anemia
- anorexia
- weight loss and delayed onset of egg laying


3. Fecal examination
Detection of oocysts
- direct smear
- flotation technique


4. Necropsy
E. tenella :
- blood and coagulated blood filled in cecum

- pin-point hemorrhage and whitish spots on cecal
  mucosa
E. necatrix :
- balloonous swelling of middle small intestine
- intestinal mucosa thickening
- blood or fluid filled in the gut
E. brunetti :
- damage in the lower small intestine, and proximal
  area of ceca
- thickening of mucosa and loss of color
- caseous erosion on the surface of mucosa
E. maxima :
- ballooning of the mid-small intestine
- thickening of mucosa
- the lumen filled with yellow mucus and blood
- blood filled gut in heavily infected chicken
- light pin-point hemorrhage on intestinal mucosa E.acervulina :
- white plaques striation throughout the intestine
  but heavy in the duodenal loop
- hemorrhagic appearance in mucosa


5. Tissue smear
Detection of merozoites, schizonts or occysts of
Eimeria spp.
- direct smear of intestinal scrapings


6. Histopathological observation
- Cellular infiltration and schizonts develop in the
  intestinal mucosa and lamina propria
- Denuded villi and damage to the mucosa


Control and treatment
- Disinfection of floor and litter with ammonia gas
  and methyl bromide (oocysts extremely resistant
  to most disinfectants)
- Prevention with effective drugs mixed in the feed
  or drinking water
- Maintaining poultry on wire floors