Week 10 Flashcards
Coccidia related vector borne agents
Agent, disease, IH, and DH

Life Cycle of Coccidia related vector borne agents
* iatrogenic- blood transfusions
* transovarial transmission in ticks for Babesia spp. only
* Sporozoite is infective phase–> injected into blood stream_-> merogony phase 1 & 2–> etc.
** Asexual phase is the pathogenic phase, remain in RBCs as macro and microgametes

Significance of Piroplasmosis

In Australia, what are the 3 main tick vectors that impact cattle and dogs?
Haemaphysalis (Bush tick), Rhipicephalus microplus (Cattle tick), Rhipicephalus sanguineus (Brown dog tick)
Distribution of Rhipicephalus microplus (cattle tick)

Global distribution of malignant theileriosis

Distribution of benign theileriosis- T. orientalis group
* compared to malignant forms it has mild pathogenecity (lucky for Australia!)- not always the case as it depends on immunity


Pathogenecity of coccidia vector borne?
* Haemolytic anaemia (hypoxia, organ damage)
- direct RBC destruction- merogony
- indirect- anti-RBC anti-bodies- splenomegaly
* Thrombocytopaenia
- splenic sequestration of platelets
- auto anti-platelet antibodies
- consumptive coagulopathy- DIC, shock
* Cytoadhesion of RBC to capillaries of brain
- cerebral babesiosis in Babesia bovis and Babesia caballi (horses)
What is unique about Theileria pathogenesis?
* Lymphadenopathy because body is trying to replace leukocytes
* Species and strain dependent on how pathogenic
* B. gibsoni would come between B. canis & B. vogeli

Immunity to piroplasms
* why in endemic areas you wouldn’t see Babesiosis- the main issue comes from naive animals exposed to ticks from introduction to a naive herd

Babesiosis in cattle

Canine babesiosis – name, vector, geography, and how pathogenic?

Babesiosis in dogs (Australasia)– what are the two genera? IHs? Clinical signs? Who?

Theileriosis in cattle- genera? What does it cause?
* cows in late pregnancy, early calving- cows are most susceptible to clinical forms
* might just see slight production loss, subclinical

Ante-mortem diagnosis of piroplasmosis
Has this dog always been in QLD?
* Cattle: Any new introductions to the herd? (especially in a tick free zone) OR have the cattle moved?

Post mortem diagnosis of B. bovis?
Impression smear of the brain due to massive numbers- capillaries of the brain are predilection site


Lymph node aspirate Schizont of T. annulata with merozoites in monocyte

Blood smear of cow infected with T. annulata

Babesia bigemina




Brain capillaries packed with infected erythrocytes parasitised by B. bovis

Normal capillary impression smear

Babesiosis

































