Ticks

Ticks

1. background

   • considerable vet importance
   • warmer parts
     • major cause of disease/production loss
   • effects
     • tick worry
     • blood losses
     • disease transmission
     • tick paralysis
     • 2nd infection - blowfly strike
     • production loss
     • fleece/hide damage

2. hard ticks

   • temperate and warm climates
   • scutum present
     • males - scutum covers entire dorsal surface
     • females - partial covering
       • expand to accomodate eggs
   • prominent mouthparts
   • festoons may be present
   • body wall - convoluted to accommodate blood meal

3. soft ticks

   • no scutum
   • mouthparts not visible
   • do not swell much
   • mouth - palps, chelicerae, hypostome
     • palps - detect subtle differences in CO2 and temp
       • detect host and blood vessel location

4. feeding

   • hypostome into skin
     • cemented
     • cont feeding
   • tick saliva
     • histamine
     • anticoagulants
     • cystolysin
     • vasoactive mediators
     • kinase
   • feeding lesion created

5. life cycle

   • larva
     • larvae
       • nymphs
         • adults
           • egg laying
   • both hard and soft ticks have same stages of life cycle
   • temporary parasites