VPA 221: Veterinary Entomology and Acarology (1+1)

MYIASIS - CONTROL

• Render sheep less attractive to flies by
  1. Selective breeding to eliminate folds in poll region / narrow breech
  2. Surgical removal of breech folds - Mules operation
     • A crescentric area on either side of urinogenital area is removed, resultant scarring flattens the skin – effective for breech strike
     • ‘Chemical mulesing’ -40% phenol  when applied along prepuce of young wethers or even in breech region
  3. Docking at 4^th instead of 2^nd caudal vertebrae  reduces strike . The short tail produced by docking at the 2^nd caudal vertebrae results in a stump surrounded by folds – “rose tail” appearance which is susceptible to strike.  A longer tail stump covers the anal area and thus makes it less susceptible
  4.  Crutching
     • Regular clipping of wool around tail, breech to prevent soiling of wool
  5. Dagging
     • Removal of faecal soiled wool
  6. Burial or burning of carcasses
  7. Use  of chemicals – Insecticides in wounds infested with larvae
• 5% coumaphos Ivermectin jetting fluid
• Oral ivermectin / closantel
• Chitin synthesis inhibitor – cyromazine is a larvicide
• Synthetic pyrethroids