Equine Parasites: Protozoa

Question 1

How would you classify Eimeria leukarti?

Answer 1

Protozoan parasite

Question 2

Describe Eimeria leukarti eggs.

Answer 2

Oval oocyst 80-60 Mm
Thick and dark colored
Distinct micropyle
Shell can come off

Question 3

What is the PPP of Eimeria leukarti?

Answer 3

15 days

Question 4

What are the 3 phases of Eimeria leukarti life cycle?

Answer 4

Sporulation
Asexual Reproduction
Sexual Reproduction

Question 5

Infection and schizogony refer to what phase of the Eimeria leukarti life cycle?

Answer 5

Asexual Reproduction

Question 6

Gametogony and oocyst formation refer to what phase of the Eimeria leukarti life cycle?

Answer 6

Sexual Reproduction

Question 7

What is the site of infection for Eimeria leukarti?

Answer 7

Small Intestine

Question 8

What pathogenesis and lesions are associated with Eimeria leukarti protozoan parasite?

Answer 8

Inflammatory changes in mucosa

Disruption of villous architecture

Question 9

What are the clinical signs of Eimeria leukarti?

Answer 9

Intermittant diarrhea

Question 10

Who is most susceptible to contracting Eimeria leukarti?

Answer 10

Foals

Question 11

How is Eimeria leukarti diagnosed?

Answer 11

Sugar flotation or specific sedimentation

Question 12

How is Eimeria leukarti treated?

Answer 12

Antiprotozoals like sulpha-drugs

Question 13

What is the common name of Sarcocystis neurona?

Answer 13

Equine Protozoal Myeloencephalitis (EPM)

Question 14

What is the definitive host of Sarcocystis neurona/EPM?

Answer 14

Opossum

Question 15

What is the intermediate host of Sarcocystis neurona/EPM?

Answer 15

Cats, skunks, raccoons

Question 16

What is the accidental/aberrant host of Sarcocystis neurona/EPM?

Answer 16

EQUINE

Question 17

What happens in the normal life cycle of Sarcocystis neurona (when on its proper DH)?

Answer 17

Gametogony in opossum (DH)

Shizogony in IH with bradyzoites in muscles of IH

Question 18

What happens when Sarcocystis neurona/EPM infects an accidental/aberrant host?

Answer 18

Schizonts in horse’s NEURONS, not in muscle cells

Question 19

Where is Sarcocystis neurona/EPM found in the US majorly?

Answer 19

Oklahoma! Also in CA and FL

Question 20

Who does Sarcocystis neurona/EPM affect most?

Answer 20

Younger horses

Question 21

Is Sarcocystis neurona/EPM pathogenic?

Answer 21

Non-pathogenic in final host, pathogenic in accidental host

Question 22

What pathogenesis does Sarcocystis neurona/EPM cause in the accidental host (horse)?

Answer 22

3rd stage schizogony in neurons instead of muscle tissue

Question 23

What are clinical signs associated with Sarcocystis neurona/EPM in horse?

Answer 23

Progressive debilitation of of CNS, brain, brainstem, and spinal cord 
Lameness
Seizures
Difficulty standing, walking, swallowing
Ataxia 
Atrophy of muscles

Question 24

What is the most commonly diagnosed infectious equine neurologic disease in North America?

Answer 24

Sarcocystis neurona/EPM

Question 25

How is Sarcocystis neurona/EPM prevented?

Answer 25

Prevent opossums from defecating where horses eat

Question 26

How is Sarcocystis neurona/EPM treated?

Answer 26

Antiprotozoals, but CNS damage that has already occurred will persist

Question 27

How successful is Sarcocystis neurona/EPM treatment?

Answer 27

70-75%

Question 28

Are sarcocysts associated with Sarcocystis neurona/EPM?

Answer 28

NO

Question 29

Where would you find schizonts and merozoites in the horse?

Answer 29

Confined to the brain and spinal cord