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Created page with '*Cattle **Sudden onset **Often fatal if untreated **Causes 'pipestem' faeces **Clumping of red blood cells in brain capillaries can occur causing neurological signs '''Epidemiol…'
*Cattle
**Sudden onset
**Often fatal if untreated
**Causes 'pipestem' faeces
**Clumping of red blood cells in brain capillaries can occur causing neurological signs
'''Epidemiology'''
*Determined by:
**Number of infected [[Ticks|ticks]] seeking a blood meal ('''tick pressure''')
**Calves under 9 months are refractory to disease
***Can develop immunity if exposed without showing clinical signs
**'Premunity' (a good protective immunity) develops quickly in infected cattle causing a 'carrier state'
**Immunity can wane in the absence of re-infection
**Uninfected cattle remain susceptible
*Predisposing factors:
**Susceptible animals introduced into an infected area
**Infected [[Ticks|ticks]] introduced into a clean area
**Infected cattle introduced into an area with clean [[Ticks|ticks]]
**Temporary reduction in the [[Ticks|tick]] population decreasing the transmission rate (causing enzootic instability)
**Infected are transported or stressed in other ways, e.g. parturition
*In the UK
**Sporadic disease
**Enzootic instability
**Occurs mostly during the spring and autumn during periods of greatest [[Ticks|tick]] activity
**Occurs mostly in stressed cattle under 2 years old on rough grazing
**''B. divergens'' the most common species
**[[Hard Ticks - UK#Ixodes spp.|''Ixodes ricinus'']] is the vector
**[[Ticks#Disease Transmission|Trans-ovarial]] transmission to the next generation occurs
**''B. major'' occurs in South East England but is not pathogenic
***Vector is [[Hard Ticks - UK#Important Hard Ticks|''Haemaphysalis'']]
*Overseas
**''B. bovis'' causes considerable losses in cattle in many tropical and sub-tropical areas
***In Australia an attenuated vaccine is used
***Vector is [[Hard Ticks - Overseas|''Boophilus'']]
**''B. bigemina'' causes problems in Africa and South America
***Vector is [[Hard Ticks - Overseas|''Boophilus'']][[Category:Piroplasmida]][[Category:Cattle]]
**Sudden onset
**Often fatal if untreated
**Causes 'pipestem' faeces
**Clumping of red blood cells in brain capillaries can occur causing neurological signs
'''Epidemiology'''
*Determined by:
**Number of infected [[Ticks|ticks]] seeking a blood meal ('''tick pressure''')
**Calves under 9 months are refractory to disease
***Can develop immunity if exposed without showing clinical signs
**'Premunity' (a good protective immunity) develops quickly in infected cattle causing a 'carrier state'
**Immunity can wane in the absence of re-infection
**Uninfected cattle remain susceptible
*Predisposing factors:
**Susceptible animals introduced into an infected area
**Infected [[Ticks|ticks]] introduced into a clean area
**Infected cattle introduced into an area with clean [[Ticks|ticks]]
**Temporary reduction in the [[Ticks|tick]] population decreasing the transmission rate (causing enzootic instability)
**Infected are transported or stressed in other ways, e.g. parturition
*In the UK
**Sporadic disease
**Enzootic instability
**Occurs mostly during the spring and autumn during periods of greatest [[Ticks|tick]] activity
**Occurs mostly in stressed cattle under 2 years old on rough grazing
**''B. divergens'' the most common species
**[[Hard Ticks - UK#Ixodes spp.|''Ixodes ricinus'']] is the vector
**[[Ticks#Disease Transmission|Trans-ovarial]] transmission to the next generation occurs
**''B. major'' occurs in South East England but is not pathogenic
***Vector is [[Hard Ticks - UK#Important Hard Ticks|''Haemaphysalis'']]
*Overseas
**''B. bovis'' causes considerable losses in cattle in many tropical and sub-tropical areas
***In Australia an attenuated vaccine is used
***Vector is [[Hard Ticks - Overseas|''Boophilus'']]
**''B. bigemina'' causes problems in Africa and South America
***Vector is [[Hard Ticks - Overseas|''Boophilus'']][[Category:Piroplasmida]][[Category:Cattle]]