Parasitology: Coccidiosis

Question 1

What is coccidiosis?

Answer 1

Enteric disease caused by the obligatory intracellular protozoa of the genus Eimeria

Question 2

How is coccidia spread?

Answer 2

Faecal-oral transmission

All breeds and ages are susceptible

Question 3

What are the clinical signs of coccidiosis in chickens?

Answer 3

Loss of appetite and emaciation
Anaemia, weakness
Diarrhoea and weight loss
Death

PM: Haemorrhage in the caeca

Question 4

What are the clinical signs of coccidiosis in rabbits?

Answer 4

Enlarged liver with multifocal greyish-white coalescing lesions/nodules and yellowish-white caseous pus caused by Eimeria stidiae

Question 5

What are the most common species of Eimeria in chickens?

Answer 5

E. acervulina, E. necatrix & E. tenella

Question 6

How many sporocysts does Eimeria have? And sporozoite?

Answer 6

4 and 2

Question 7

What is the PPP of E. Bovis

Answer 7

17-22d

Question 8

How does coccidiosis cause growth faltering

Answer 8

Small intestine mucosal damage

a) villus atrophy and loss of mucosal enzymes leads to malabsorption
b) barrier function compromised leads to secondary infection

Question 9

Is sub clinical coccidiosis common in cattle?

Answer 9

This very common form of the disease may account for as much as 95% of all losses associated with coccidiosis
» Carcass in good flesh is approved. If the disease is associated with emaciation, the carcass is condemned

Question 10

Lesion scores indicate the pathological changes in the intestines on a scale of 0 to 4., what do these scores mean?

Answer 10

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

Question 11

What does E. acervulina cause ?

Answer 11

mild disease: upper small intestine, lesions in duodenum
older chickens
laying hens = drop in egg production

Question 12

What does E. necatrix cause?

Answer 12

severe disease: mid-small intestine
bloody diarrhoea
death

Question 13

What does E. tenella cause?

Answer 13

severe disease: caecae
only involves the caecum
severe disease in chickens less than 6 mos. old

Question 14

What does E. tenella cause?

Answer 14

severe disease: caecae
only involves the caecum
severe disease in chickens less than 6 mos. old

Question 15

When is coccidiosis most common in sheep?

Answer 15

(March), April, May, June

Question 16

How do we Control and Prevent Coccidiosis?

Answer 16

1) Accurate diagnosis
2) Good management of the premise (Limit exposure & reduce stress)
3) Treatment of clinical cases
4) Use of preventive medication (Coccidiostats)

Metaphylactic treatment is superior to therapy

Question 17

Transmission of infection from cow-to-cow?

Answer 17

Not possible

Question 18

Transmission via placenta or milk (lactogenic)?

Answer 18

Not but may be through drinking contaminated milk.

Question 19

Is coccidiosis a zoonotic infection?

Answer 19

This parasite is highly host specific. Cattle species can not infect humans.