Coccidiosis is a protozoan disease of chickens caused by Eimeria species parasites that infect different areas of the intestines. It is characterized by diarrhea, intestinal hemorrhaging, and lesions. Clinical signs include anorexia, bloody diarrhea, and death. Diagnosis involves finding oocysts in fecal smears and identifying lesions during post-mortem examination. Control relies on preventative medication, vaccination, sanitation, and chemotherapy during outbreaks.

1. COCCIDIOSIS

2. OVERVIEW
• Definition
• History
• Etiology
• Clinical signs
• Post mortem Lesions
• Diagnosis
• Differential diagnosis

3. DEFINITION:
Acute or Chronic protozoan disease
characterized by
ü High morbidity
ü Enteritis
ü Mucoid to bloody diarrhea
ü Haemorrhagic intestine
ü Caecal lesions
ü Death

4. History
Rivoita (1869) first described coccidia in
domestic fowl

5. ETIOLOGY:
The disease is caused by
Coccidia
genus Emeria.

6. SUSCEPTIBLE HOSTS
l Chicken is the only natural
host
l All ages and breeds are
susceptible

7. 3 week old chicken

8. 6 week old brioler

9. CHARACTERISTICS
Ø Host specific
Ø Site specific
Ø Short direct life cycle
Ø Immunity quickly develops after exposure and
gives protection against later disease out break
Ø No cross immunity between species of Emieria

10. SPECIES AFFECTING CAECA
E. tenella

11. SPECIES AFFECTING SMALL
INTESTINE
1. E. acervulina
2. E. brunette
3. E. praecox
4. E. maxima
5. E. mitis
6. E. mivati
7. E. necatrix
8. E. hagani

12. Site parasitized by Eimeria praecox

13. Proposed site parasitized by Eimeria mivati

14. Site parasitized by Eimeria acervulina

15. Site parasitized by Eimeria necatrix

16. Site parasitized by Eimeria maxima

17. Site parasitized by Eimeria brunetti.

18. Site parasitized by Eimeria mitis

19. l Proposed site parasitized by Eimeria
hagani
Proposed site parasitized by Eimeria hagani

20. TRANSMISSION
HORIZONTAL
Mechanical transmission by

21. Wild birds

22. TRANSMISSION
By feet, hands, clothing, dust and
contaminated equipments
Mixing of infected birds, recover birds are
carrier for several months

23. VERTICAL:
Not reported

24. PATHOGENESIS:
l Ingestion of Sporulated oocysts
l Wall of oocyst is broken down in gizzard (by
mechanical action and enzymatic activity) and
release of sporozoite
l Enter cell of intestinal mucosa
l Tissue damage due to
l At least 2 generations of asexual development
(schizogony) and then sexual phase
l Oocyst is released from mucosa and is shed in the
faeces

26. Eimeria tenella sporulated oocyst
Eimeria tenella unsporulated oocyst

27. Eimeria maxima oocysts
A mixture of different species
of Eimeria oocysts

29. Eimeria tenella merozoites in schizonts Eimeria tenella merozoites

30. Eimeria tenella microgametocytes and macrogametocyte

31. CLINICAL SIGNS
l High morbidity
l Anorexia
l Mal-digestion and mal-absorption
l Bloody diarrhea
l Death due to loss of blood

32. Anorexia , Depression, stunted growth

33. Weak birds, loss of weight and increase
culling rate

34. Weak and listless birds

37. STRESS

38. Coccidia as it looks in manure

39. POSTMORTEM LESIONS:
CAECAL
l Swollen (3 – 4 times enlargement)
l Haemorrhages on mucosal surface
l Lumen filled with blood

40. Gross lesions of Eimeria tenella with frank
hemorrhaging into cecal pouches, broiler chicken

42. Gross lesions of Eimeria necatrix with frank
hemorrhaging into midgut, chicken.

43. Site parasitized by Eimeria acervulina

44. Gross lesions of Eimeria acervulina with white
longitudinal plaques in the duodenal loop.

45. Site parasitized by Eimeria brunetti.

46. Gross lesions of Eimeria brunetti in small intestine, broiler
chicken.

49. INTESTINAL:
lBright red congestion or
haemorrhagic appearance
lPin point haemorrhages
lWhitish yellow plague
lContents are brown, orange, pink or
red brown

50. DIAGNOSIS:
1. History
2. Clinical sign
3. Postmortem lesion
4. Lesion scoring & dropping score

51. Oocysts of Eimeria maxima, 100X

52. 5- Microscopic examination of wet smear of
mucosal surface scraping
Developmental stages of Eimeria necatrix from scraping of
midgut

53. Developmental stages of Eimeria acervulina from mucosal
scraping of duodenal loop, new methylene blue, 40X

54. Oocysts of Eimeria brunetti from mucosal scraping of small
intestine, new methylene blue, 100X

55. Release of merozoite from mature schizont, new
methylene blue, 100X

56. CONTROL
l Preventive medication
l Immunization
l Disinfection and sanitation
l IN CASE OF OUTBREAK
lChemotherapy (Sulphaquinoxaline,
Amprolium)
lSupportive medication(Vit. A,D,E,K)
lAntibiotics