Coccidia

Question 1

What constitutes a member of the Apicomplexica phylum?

Answer 1

All are parasitic, no locomotory organelles, all have apical complex

Question 2

What are the five components of an apical complex?

Answer 2

Polar ring, conoid, micronemes, rhoptries, subpellicle microtubules. Involved in infiltration of the cell

Question 3

What are the stages of the apicomplexa?

Answer 3

the -zoites, the -onts, and gametocytes

Question 4

What stage is the -zoite?

Answer 4

The motile, active form

Question 5

What stage is the -ont?

Answer 5

Usually non-motile

Question 6

What stage is the gametocytes?

Answer 6

The structures with products of gamete formation

Question 7

How many hosts do coccidia have?

Answer 7

one

Question 8

How many life stages does coccidia have?

Answer 8

Three- schizogony, gametogony (both inside host), and sporogony (outside host)

Question 9

How do coccidia reproduce?

Answer 9

Asexually by multiple fission inside the host, and sexually by gametogony inside the host

Question 10

What is sporogony?

Answer 10

The production of an oocyst, sporulates outside host to become infective

Question 11

How many sporocysts and sporozoites does Eimeria have?

Answer 11

4 sporocysts, 2 sporozoites

Question 12

How many sporocysts and sporozoites does Isospora have?

Answer 12

2 sporocysts, 4 sporozoites

Question 13

How does host specificity compare between Eimeria and Isospora?

Answer 13

Eimeria is very host specific, usually present in herbivores, while Isospora have less specificity and usually are present in carnivores (swine are exceptions)

Question 14

What is the typical life cycle of a coccidia?

Answer 14

Ingestion of an infective (sporulated) oocyst; sporocyte released, enters an epithelial cell, becomes a schizont, merozoites develop inside the schizont, schizont bursts and merozoites are released, which enter another epithelial cell. Usually 2-3 generations of schizonts/merozoites. The 2nd or 3rd generation merozoite enters another epithelial cell, becomes a micro- or macrogametocyte, which is fertilized and forms a zygote that forms into an oocyst. Oocyst ruptures and passes out feces, sporogony occurs outside host making the oocyst infective.

Question 15

What are micro- and macrogametocytes?

Answer 15

Male and female gamonts (respectively), microgametes fertilize the macrogametocyte

Question 16

What does coccidiasis mean?

Answer 16

The presence of coccidian parasites in a host

Question 17

What does coccidiosis mean?

Answer 17

The presence of coccidian parasites and the resulting clinical signs

Question 18

What are the intestinal signs of coccidiosis?

Answer 18

Diarrhea, dehydration, statorrhea, tenesmus, sloughing pieces of mucosa, fever, anorexia

Question 19

What are the methods for managing the epidemiology coccidiosis?

Answer 19

Decreasing moisture, grouping animals by age, decreasing stress caused by weather, nutrition, shipping, dehorning, castration. Reduce dispersion by humans, wind, birds, etc.

Question 20

What are methods for controlling coccidiosis in a herd?

Answer 20

Sanitation, chemoprophylaxis (prevention via drugs), chemotherapy (treatment with drugs), immunity

Question 21

What is the life cycle of Eimeria tenella?

Answer 21

Oocytes are passed in feces, perform sporogony, ingested by host, then proceeds like normal coccidia

Question 22

How long can Eimeria oocysts stay infective in the environment?

Answer 22

2-3 months

Question 23

How long is the prepatent period of Eimeria tenella?

Answer 23

about 7 days (period between ingestion and first appearance of oocysts in the feces

Question 24

What age is most commonly infected by Eimeria tenella?

Answer 24

About four weeks of age, referred to as “cecal coccidiosis”

Question 25

What contributes to the varying pathogenesis of Eimeria tenella?

Answer 25

Depends on size of infecting dose, breed, age, nutritional status and stress factors

Question 26

What are the clinical signs of Eimeria tenella?

Answer 26

Diarrhea and massive cecal hemorrhage, blood appearing 4 days post-infection, greatest hemorrhage between 5-6 days after infection. On the 7th day cecum changes from red to mottled reddish-white. Recovery is slow, might be affected by anemia, older birds develop immunity.

Question 27

What is the life cycle of Eimeria necatrix?

Answer 27

1st and 2nd generation schizonts are in the small intestine, 3rd generation schizonts and gametogony occur in the ceca

Question 28

What is the pathogenesis of Eimeria necratrix?

Answer 28

Pathology in the middle third of the small intestine, causes extensive scarring, lesions are small and white and death occurs in 5-7 days PI

Question 29

What are the treatments for avian coccidia?

Answer 29

Sulfonamides, amprolium

Question 30

What are ways to prevent avian coccidia?

Answer 30

Decoquinate, lasalocid, monesin

Question 31

What are the vaccines available for avian coccidia?

Answer 31

Livavox, paracox, coccivac, not as effective as continuous prophylaxis

Question 32

How does one diagnose avian coccidia?

Answer 32

With a post mortem exam or a fecal

Question 33

What is Eimeria adenoides?

Answer 33

“Turkey coccidia” PPP 4-6 days, Patent period 7-20 days, most of life cycle takes place in the lower 1/3 of the SI, ceca and rectum

Question 34

What is the pathogenesis of Eimeria adenoides?

Answer 34

Anorexia, droopy wings, ruffled feathers. Terminal intestine becomes swollen and edematous on day four, petechial hemorrhages filled with mucous

Question 35

What is the pathogen that causes goose coccidia?

Answer 35

Eimeria truncata