This document provides information on various protozoan parasites that infect the gastrointestinal tract, known as enteric coccidia. It defines protozoa and describes their characteristic features including morphology, locomotion, reproduction, and classification. It then focuses on the phylum Apicomplexa, outlining the main characteristics and providing examples such as Eimeria, Isospora, Cryptosporidium, and Cyclospora. The document discusses the life cycles, pathogenesis, diagnosis and control of these important enteric coccidia, emphasizing their clinical significance and the different disease syndromes they can cause in hosts.

1. ©
Alexandria
Faculty of
Veterinary
©
Alexandria
Faculty of
Veterinary
©
Alexandria
Faculty of
Veterinary
©
Alexandria
Faculty of
Veterinary©
Alexandria
Faculty of
Veterinary©
Alexandria
Faculty of
Veterinary
Prof Dr. Somaia Saif

2.  What are Protozoa?
 The characteristic features of Protozoa,
 Morphology
 Locomotion
 Reproduction: Asexual reproduction, Sexual reproduction
 Classification
 The main characters of Phylum Apicomplexa.
 Enteric coccidia:Cystisospora, and Cyclospora.

3. Classification of Protozoa
Kingdom Protozoa
Group 1 Apicomplexa (Sporozoa) e.g. Eimeria
Group 2 Mastigophora (Flagellates) e.g.
Trypanosoma
Group 3 Ciliophora (Ciliates) e.g. Balantidium
Group 4 Amoeba( sarcodina)
e.g.Entamoeba
Group 5 Microspora moved to the kingdom Fungi, as
the phylum Microsporidia- e.g. Encephalitozoon

5. Enteric Coccidia
G. Eimeria
G. Isospora
G. Cryptosporidium
G. Cyclospora(Cystisosopora)

6.  Definition
 General characters
 Life cycle
 Pathogenesis& signs
 Diagnosis
 Control
 Important species

7. Genus: Eimeria

8.  Intracytoplasmic
 Mainly enteric except:
-E.stiedae (liver of rabbit),
-E.truncata (kidney of goose)
 Affect all animals except dog and cat
 Causes a sever disease called: Coccidiosis

9.  Cosmopolitan
 Spreading of the disease increases in winter and
spring(humidity)
 Intensive breeding farms are highly susceptible

10.  Monoxenous parasite
 Host specific
 Cell specific
 Multiplication of the parasitic stages occurs in:-epithelial
cells of mucosa or may reach sub mucosa of the intestine
Except: E.stiedae & E.truncata.
 Multiplication is mostly intracytoplasmic except some
species (E.alabamensis) which multiplies inside the
nucleus.

11. AsexualReproduction
Sexual Reproduction
Sporulation
Life CycleLife Cycle
Management
Treatment

12. Life Cycle
Schizogony
)Merogony(
Gametogony
)Gamogony(
)Sporulation
)sporogony(
Sporulated OocystMerozoites Microgametocytes Macrogametocytes

13.  Infective stage: Sporulated oocyst
 Mode of infection: Ingestion of sporulated
oocysts.
Cont.

14. Polar granule
Stieda body
Sporocyst
Sporozoite
Oocyst residual body
Sporocyst residual body
Eimeria sp.: Sporulated oocyst

15. Conoid
Microneme
Rhoptry
The penetrating stage contain complex structures at the apical
end.
The penetrating stage contain complex structures at the apical
end.

17. Cap
Oocyst wall
double layers
One cell
embryo
Yolk cells
Eimeria species: Unsporulated oocyst

18. Eimeria tenella
Eimeria maxima

19. ©Alexandria Faculty of Veterinary Medicine

20. LC period
1-2 weeks
Host

22. Requirments of sporulation:
*Oxygen
*Adequate moisture
*Temprature
 Time required for sporulation:1-7
days(except:Eimeria of camel,17 days).
 Sporulated oocysts are more resistant to
environmental conditions than unsporulated
oocysts.

23. Schizont
(Meront(
Schizont
(mature(
Merozoites
MZs

24. First generation schizont (meront), E.bovis

25. Biflagellate microgamete
Microgametocyte

26. Microgametocyte

27. Eosinophilic granules
Nucleus
Wall- one layer
Macrogametocyte

28. Macrogametocytes

31. Epidemiology
■ Coccidial infections are self-limiting
i.e. (in the absence of re-infection, one cycle of
development can take place).
■ Under natural infections, repeated infection usually
occurs in closed farms.
■ Repeated infections with small number of oocysts,
induce the development of immunity.
■ Old ages are immune hosts (carriers).

34. Depends on:
1. Location of the parasite in the host tissue.
2. Size of the infecting dose.
3. Acquired immunity.
4. Age of the host.
5. Species of the parasite.(Virulence)
 parasite can destroy epithelial cells causing villus atrophy &
hemorrhage is seen in severe disease
 majority of pathology caused by asexually replicating stages vs.
sexual stages, therefore see clinical signs of disease prior to
presence of oocysts

35.  Diarrhea
 blood may or may not be observed in feces
(depends on species & severity of infection)
 poor weight gain, emaciation & death
 Death or acquired immunity and self cure

36. The most pathogenic and important species in domestic
poultry
 Chicken huddle together& stop feeding.
 Hemorrhagic enteritis.
 Mortality is highest between 4th
&6th
day due to
excessive loss of blood.
E.tenellaE.tenella

44. Hepatic coccidiosis

45. In E.tenella:
 1st
3 days: Petechial haemorrhages
 4th
day: Hemorrhagic spots
 5th
-6th
day: Dilatation of cecum+blood in lumen
 7th
day :Cecal core(clotted blood+ tissue debris)
 8th
day: Cecal core is detached from m.m. &shed in
faeces

49. Eimeria tenella in caecum

52. E.acervulina-chicken, hemorrhagic enteritis
Source Ontario Veterinary college, Canada

53. Hepatic coccidiosisHepatic coccidiosis

54. Hepatic coccidiosis
Normal liver

55.  Clinical signs.
 Gross lesions(P.M Lesions).
 Microscopical examination

56.  Direct smear.
 Floatation technique
 Fecal culture(2.5% Pot. dichromate sol.).
 Stained intestinal smear(Giemsa Stain).
 Histopathological examination(H&E stain)

61.  Good diagnosis
 Treatment
 Prophylaxis

62.  Many different drugs have been used for therapy:
(coccidiostatics e.g. Amprolium, Sulfa drugs, Some drugs have
a cidal effect (e.g. Panzuril, Diclazuril, Toltrazuril) mixed with
food or water.
 Used for 3-5 days for treatment
&repeated after 10-14 days + Good hygiene.

63. - Prophylactic programs: Rotation of anticoccidial drugs to prevent
the drug resistance:
A-Shuttle program.
B-Switch program (slow rotation)
- Environment - reducing exposure to oocysts through good management can
prevent or reduce severity of disease. e.g Good sanitation.
- oocysts resistant to most disinfectants but steam cleaning, immersion in
boiling water or 10% ammonia solutions (e.g. food & water bowls) .
- Vaccination.

64. Species E.tenella E.necatrix E.acervulina
Pathoginicity Pathogenic Less
pathogenic
Lcalization Caecum Mid
S.I(Schizont)
&caecum(Ga
mont)s
Anterior S.I

65. SIGNS&
P.M
LESIONS
E.tenella
Increase of
mortality
Dilated
caeci(caecal
core)
E.necatrix
Petechial
haemorrhage
White
necrotic foci
Emaciation in
chronic cases
E.acervulina
Watery
diarrhea
Weight loss
Low
production

66. E.Stiedae
(Hepatic coccidisis)
E.intestinalis E.media
Affect liver(epithelia
of bile duct)
Affect small intestine
•Diarrhae
Salivation
Enlarged liver&white
necrotic foci

67. Turkey E.meleagridis E.adenoides
Ducks&Geese E.anseris E.truncata
Quails E.bateri E.uzuzra

68. E.bovis E.zuernii
Pathoginic Pathoginic
Affect S.I +Caecum&colon As E.bovis
Giant 1st
generation
schizont(120000
merozoites).
1st
generation schizonts
are 7-10um(25
merozoites)

69. E.ahsata E.arloingi E.crandalis
Pathogenic Pathogenic Less pathogenic
Afffect ileum Affect S.I
(Giant schizonts)
Affect cecum&
colon

70. E.cameli E.dromedari
Affect S.I
Giant oocyst
(91X79um(
Giant schizonts
28X23um
(oval)
Sporulation time:10-15
days
15-17 days

71. E.leukarti E.solipedium
Affect S .I
Large oocyst (77X55um(
(rough and brown)
Oocyst,15X28um
(orange red or yellowish
brown)

72. -Extracytoplasmic coccidian protozoans.
-- Intracellular, extra-cytoplasmic parasites of
epithelial cells lining the gastrointestinal and
respiratory tracts of many different vertebrates
■ Attached to the luminal border of host cells,
enveloped in parasitophorus membrane.
■ Zoonotic parasite
G. CryptosporidiumG. Cryptosporidium

73. ■Distribution allover the world
■Affect all vertebrates
■Direct life cycle

74.  Sporozoites, Merozoites, Meronts and Gamonts
 - similar to Eimeria
 Oocysts
 oocysts are spherical and very small 4 - 6 um
 all are sporulated (therefore immediately infective) when
passed in feces
 - Cryptosporidium oocysts contain 4 ‘naked’ sporozoites (no
sporocysts).

75. ingestion

77. Pathogenesis and symptoms of
cryptosporidiosis
■More pathogenic in young hosts 1-3 months.
■Catarrhal enteritis – watery diarrhea
■Pneumonia, swelling of bursa in birds.
■Also, sings of other complications
AIDS and Esch.coli.

82. Diagnosis
■Symptoms
General intestinal or respiratory troubles.
■Lab. exam
□ Direct fecal examination using Sugar concentration
technique, examined under oil immersion x100.
□Stained fecal smears use Modified Zeihl– Nelseen
(MZN stain(.
□ Histopathological exam.
 Immunofluorescence antibody.

84. - Good diagnosis
- no treatment currently available, although halofuginone &
azithromycin have recently (2008) shown some efficacy in calves
- sanitation and good management practices are necessary to
reduce exposure to oocysts
- supportive care (fluids, electrolytes, reduce stress)
- adequate nutrition
- cryptosporidosis may be a chronic disease of the
immunocompromised and can be life threatening (AIDS patients,
immunosuppressive therapy)
- calves & lambs must receive adequate colostrum.
ControlControl