Tick Borne Diseases of Livestock Flashcards
what are the 4 primary groups of tick pathogens that are important in livestock
- protozoan parasites
- babeseia
- theileria
- rickettsias
- anaplasma
- ehrlichia
what are the two theileria species
theileria annulata
theileria parva
where is theileria annulata a disease of
southern europe
north africa
middle east
asia
where is theileria parva a parasite of
east/central africa
what does theileria annulata cause
tropical theilerosis
what does theileria parva cause
east coast fever
what does transtadial mean
Transstadial transmission is the sequential passage of parasites acquired during one life stage, or stadium, through the molt to the next stage(s) or stadium.
what is the life cycle of theileria annulata/parva
- Tick feeds/inoculates sporozoites
- Sporozoite invades leukocytes to divide — causes cancer like disease
- Lymph node hyperplasia/followed by fever/infection spreads
- Goes to lungs and causes pulmonary edema respiratory distress
- Lymphocytolysis and depressed leucopoeisis causes — leucopenia severe damage to and disorganization of lymphoid system
- Death within 18-26 days
- In T. annulata anemia/jaundice
- Destruction of infected RBC/autoimmune response against RBC
how is theileria diagnosed
lymph node biopsy
ID of parasite in infected leukocyte
Giemsa stain, immunofluorescence PCR
how is theileria treated
buparvaquone
how is theileria controlled
acaracides dipping
vaccination
what is babesia
intraerythrocytic parasite of all domestic animals
what are the mammalian hosts of babesia
cattle
sheep
horses
pigs
dogs
what is the vector of babesia
ixodid (hard) ticks
where is babesia distributed
worldwide
what are the species of babesia that cause babesiosis in northern europe/UK
b. divergens
b. major
what is the vector of babesia divergens
ixodes ricinus
what is the vector of babesia major
haemaphysalis punctata
what is the species of bovine babesiosi in tropical/sub tropcial regions
b bovis
b bigemina
what is the vector of subtropica/tropical babesiosis
rhipicephalus ticks
how is babesia infection transmitted
Infection is acquired by the adult tick and transmitted through the egg to the larvae, nymphs or adults of the next generation
what is the pathogenesis of b divergens and b bigemina
B. Divergens and B. Bigemina — classical hemolytic anemia
Sporozoite infects erythrocytes
Parasites multiply in erythrocytes up to 40% parasitemia
Marked fall in packed red cell volume (<20%) — tissue anoxia — organ damage
Up to 75% of erythrocytes can be destroyed
- Through mechanical disruption or erythrocytes by parasites
- Increased osmotic fragility and phagocytosis of infected and uninfected RBC
what is the pathogenesis of b bovis
Rapid fall in PCV (<20%) when parasitemia is low (<1%)
Due to release of substances that activate plasma components
Increase vascular permeability, vasodilation and intravascular coagulation
Results in circulating stasis and shock followed by destruction of erythrocytes —> tissue anoxia
Slugging of parasite infected cells in capillaries of brain
Anoxia & death: aggression, incoordination or convulsions
how is babesiosis diagnosed
Clinical signs: classic sign of fever
Hemoglobinuria
Time of year: associated with tick activity
Herd and farm circumstances: naive animals
Confirm by blood smear: Giemsa stain acridine orange
Species specific Ab and PCR tests
