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==Introduction==
==Introduction==
Ticks are ectoparasites which live by hamatophagy on the blood of mammals, birds and sometimes reptiles and amphibians. Ticks are of considerable veterinary importance, particularly in warmer climates where they can cause substantial economic losses through decreased productivity and disease. They are also also important in human medicine as they cause [http://en.wikipedia.org/wiki/Lyme_disease Lyme Disease] and [http://en.wikipedia.org/wiki/Tick-borne_meningoencephalitis tick-bourne encephalitis/meningoencephalitis].
Ticks are ectoparasites which live by hamatophagy on the blood of mammals, birds and sometimes reptiles and amphibians. Ticks are of considerable veterinary importance, particularly in warmer climates where they can cause substantial economic losses through decreased productivity and disease. They are also also important in human medicine as they cause [http://en.wikipedia.org/wiki/Lyme_disease Lyme Disease] (boreliosis) and [http://en.wikipedia.org/wiki/Tick-borne_meningoencephalitis tick-bourne encephalitis/meningoencephalitis].
Ticks decrease productivity by causing fleece and hide damage, preventing animals from feeding (tick worry), ascending motor paralysis and anaemia. Infestation can also lead to secondary infection from '''blowfly''' and '''screw-worms''' leading to '''strike'''.
Ticks decrease productivity by causing fleece and hide damage, preventing animals from feeding (tick worry), ascending motor paralysis and anaemia. Infestation can also lead to secondary infection from '''blowfly''' and '''screw-worms''' leading to '''strike'''.
==Disease Transmission==
==Disease Transmission==
*'''Trans-ovarian''' transmission
*'''Trans-ovarian transmission'''
**Infection is passed from one generation of ticks to the next through the '''egg'''
**Infection is passed from one generation of ticks to the next through the '''egg'''
**E.g. ''Babesia''
**E.g. ''Babesia''
*'''Trans-stadial''' transmission
*'''Trans-stadial transmission'''
**Parasite or microbial organism is ingested during feeding
**Parasite or microbial organism is ingested during feeding
**Organism passed onto the next host as the tick develops (only in two and three host ticks)
**Organism passed onto the next host as the tick develops (only in two and three host ticks)
==Ticks of Veterinary Importance==
==Ticks of Veterinary Importance==
===Important Hard Ticks===
*''Haemaphysalis'' sp.
**Cattle
**Transmits ''Babesia major'' a relatively non-pathogenic protozoan parasite
**Uncommon
*''Dermacentor'' sp.
**Sheep
**Rare
*''Rhipicephalus'' spp.
**Warmer climates
**Causes paralysis in livestock
**Vectors for:
***''Theileria parva'' which causes East Coast Fever
***''Babesia bigemina'' which affects ruminants, mainly in Africa
***''Babesia canis'' and ''Ehrlichia canis'' which affects dogs in warmer climates worldwide
*''Boophilus'' spp.
**Warmer climates
**Vectors for ''Babesia'' spp.
**Vectors for the bacteria ''Anaplasma'' which affects cattle
*''Amblyomma'' spp.
**Warmer climates
**Transmits ''Cowdria ruminatium'' (heartwater) in Arfica
**Transmits 'Q-fever' and 'Rocky Mountain Spotted fever' in southern USA
*''Hyalomma'' spp.
**Warmer climates
**Old World
**Parasites a wide range of both domestic and wild animals
**Involved in the spread of ''Theileria'' and ''Babesia'' spp.
**E.g. ''H. aegyptium'' is a parasite of tortoises in North Africa which has been spread around the world by the pet trade
====''Ixodes'' spp.====
*''Ixodes ricinus''
**3 host tick
**Life cycle takes an average of 3 years to complete (range of 2-7 years)
**Only feed for a few days each year at each life cycle stage
**Most of their time is spent on the ground
**Adult female lays several thousand eggs on the ground in matted vegetation
***E.g. Rough pasture, hedgerows etc.
*''Ixodes canisuga''
**Host specific dog tick
**Problem in kennels
*''Ixodes hexagonus''
**Hedgehogs, dogs, cats, ferrets and wealels
**Common in small animal practice
===Important Soft Ticks===
==Control==
==Control==