Lecture 2 - Large Animal (Babesia and Theileria)

Question 1

what species of Theileria infect cattle?

Answer 1

T. orientatlis

Question 2

What species of babesia and theileria infect equine?

Answer 2

T. equi and B. caballi

Question 3

what is the difference between babesia and theileria life cycles

Answer 3

babesia sporozoites only infect RBCs but Theileria sporozoites infect lymphocytes then RBCs

Question 4

Theileria orientalis has _____ in RBCs and _____ in WBCs

Answer 4

piroplasms; schizonts

Question 5

what is T. orientalis transmitted by

Answer 5

asian longhorn tick

Question 6

T/F: T. orientalis has a Ikeda genotype that is virulent

Answer 6

TRUE

Question 7

what is used to classify Theileria genotypes?

Answer 7

major piroplasm surface protein

Question 8

define parthenogenic

Answer 8

females clone themselves as a form of reproduction

Question 9

describe the pathogenesis of T. orientalis

Answer 9

direct destruction of erythrocytes (hemolytic anemia)

Question 10

T/F: schizonts do not play a major role in the pathogenesis of T. orientalis

Answer 10

TRUE

Question 11

the severity of T. orientalis infection depends on what 2 factors

Answer 11

1. infective dose
2. host health

Question 12

what are acute clinical signs of T. orientalis

Answer 12

fever
pale, icteric mucous membranes
lethargy, weight loss
dyspnea

Question 13

what are the chronic clinical signs of T. orientalis

Answer 13

relapses with stress/immunosuppression
weight loss
decreased production

Question 14

what can be used to diagnose T. orientalis? Which is the best and why?

Answer 14

1. parasite visualization
2. serology
3. PCR

PCR is best because you can differentiate from less virulent strains

Question 15

T/F: there are medications and herd management ways to treat T. orientalis

Answer 15

FALSE - no treatment or herd management protocols

Question 16

what are 3 ways to prevent tickborne diseases

Answer 16

1. biosecurity (testing new cattle)
2. tick control
3. environmental (limiting exposure)

Question 17

why is the incidence of T. orientalis increasing in the U.S.

Answer 17

movement of asymptomatic, infected cattle

Question 18

what is a differential diagnosis for T. orientalis? why?

Answer 18

anaplasmosis because of the morale bodies present on visualization

Question 19

T/F: naive and immunocompromised individuals are more susceptible to T. orientalis

Answer 19

TRUE

Question 20

T. equi and B. caballi are transmitted by

Answer 20

1. ticks
2. iatrogenic (transfusion or contaminated needles)
3. transplacentally

Question 21

what is the pathogenesis of T. equi and B. caballi

Answer 21

direct destruction of RBCs (hemolytic anemia)

Question 22

T/F: B. caballi do not form schizonts

Answer 22

TRUE

Question 23

T/F: T. equi lymphocytic schizonts play a role in pathogenesis

Answer 23

FALSE

Question 24

what are the acute phase clinical signs of equine piroplasms

Answer 24

fever, pale mucous membranes, inappetence, weight loss, edema, splenomegaly, anemia, thrombocytopenia

Question 25

T/F: there are acute and chronic phases of tick-borne disease in large animals

Answer 25

TRUE

Question 26

what are the chronic phase clinical signs of equine piroplasms

Answer 26

weight loss
poor performance
subclinical infections

Question 27

on parasite visualization, what do tuleria equi and babesia caballi look like

Answer 27

T. equi - small four-petaled flower
B. caballi - large leaflets

Question 28

how are equine piroplasms treated in nonendemic countries

Answer 28

imidocarb dipropionate injections (USDA approved)

Question 29

why do endemic countries WANT subclinical infections of T. equi or B. caballi

Answer 29

allows for life-long immunity

Question 30

what is the management of equine piroplasmosis in the United States

Answer 30

1. USDA oversight
2. Quarantine zones
3. Outbreak response

Question 31

what are the risk factors for horses in the U.S. to get piroplasmosis

Answer 31

1. importation from endemic countries
2. unregulated racing event
3. quarterhorses