Parasitic protozoa- Coccidiosis

Question 1

What is coccidiosis?

Answer 1

• An enteric disease causing by Eimeria
• faecel-oral transmission
• all breeds/ ages susceptible
• high morbidity/ mortality in young
• Major problem in poultry

Question 2

What are the challenges of coccidiosis?

Answer 2

• Residues, particularly of ionophores, in food and eggs. Could cause adverse effects on humans,

Question 3

What are the clinical signs chicken present with?

Answer 3

• Loss of appetite
  -Emaciation
  -Anaemia/ weakness
  -Diarrhoea
  -Weight loss
  -Death
  (PM finds= haemorrhage in caeca- Eimeria tenella)

Question 4

What are the clinical signs in a rabbit?

Answer 4

-Enlarged liver with multifocal greyish lesions/ nodules and presence of yellow liquid (Eimeria Stidae)

Question 5

What species of Eimeria are found in broiler chickens?

Answer 5

• E. acervuline, E. necatrix and E.tenella

Question 6

What is a sporozoite?

Answer 6

A spore, formed inside oocyst of some coccidian species AFTER maturation of the oocyst. INFECTIOUS UNIT. Infects intestinal cells and oocyst ingestion.

Question 7

Which Eimeria species are responsible for coccidiosis in cattle?

Answer 7

-E. bovis
-E. zuernii
(Long PPP 17-22 days)

Question 8

Which mechanisms are responsible for poor growth in coccidiosis?

Answer 8

• Small intestinal mucosa is damages= atrophy of the villi leading to loss of mucosal enzymes (malabsorption/ maldigestion) FUNTIONAL DISORDER
• Barrier function compromised STRUCTURAL DISORDER
• Secondary infections leading to mucosal inflammation and immune reaction

Question 9

Describe sub-clinical coccidiosis

Answer 9

• Very common
• Big economic burden
• Is carcass is emaciated it is condemned

Question 10

How do you diagnose coccidiosis?

Answer 10

-Lab diagnosis
Metabolic parameters
Faecel smears
McMaster method
PCR
Serology

-Pathology diagnosis is specific but time consuming

Question 11

Describe the lesion scored used in pathological diagnosis of cccidiosis

Answer 11

0= no lesion
1=very mild changes
2= mild lesions
3= quite severe damage
4= severe damage to intestines

Question 12

Describe E. acervulina

Answer 12

• Causes mild disease in upper SI
• Affects older chickens
• Laying hens= lower egg yield
• Lesions in duodenum

Question 13

Describe E.necatrix

Answer 13

• Causes severe disease in the small intestine
• Blood diarrhoea
• Death

Question 14

Describe E.tenella

Answer 14

Severe dissease in he caecae (ONLY involved caecum)

-Severe disease in chickens under 6 months