Chorioptic Mange

Introduction

Chorioptes is a non- burrowing mite which resides on the skin surface

Hosts: Cattle, Sheep, Goats, Horses, Rabbits

Predilection sites: Skin- especially legs, feet (particularly heavily feathered horses), udder, abdomen and base of tail

Life cycle: Egg- Larvae- Nymph- Adult. This lifecycle takes around three weeks to complete. Eggs are found attached the the surface of the skin. Adults can survive off the ground for around three weeks, meaning transmission can be via bedding and housing as well as by direct contact.

All species are thought to be affected by the same strain of mite Chorioptes bovis

Pathogenesis

Chorioptes' mouthparts do not pierce the skin and they feed on skin debris and exudate, meaning is pathogenic significance is mild.

In cattle, economic significance is the main factor as infestation can cause damage to the hide by self trauma.

Clinical Signs

Often seen in rough-legged horses with heavy feathering

• Induce crusty skin and lesions below the hocks and knees

• Mild condition in cattle
  • Rubbing and scratching
  • Hide damage
  • Usually affects the base of the tail, perineum and udder

• Usually found on legs of sheep
  • Mild condition

• Host-specific
• In cattle, horses, goats
• Caused by Chorioptes spp.
• Grossly:
  • Erythematous, papular, crusty lesions
  • Hairless, thickened skin
  • Areas usually affected:
    • Horses: lower hind legs
    • Cattle: lower hind legs, scrotum, perineum, tail, udder, thigh
    • Sheep: lower hind legs and scrotum
    • Goats: lower hind legs, hindquarters, abdomen