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

• Cattle and Small Ruminants
  
• Usually mild conditon
• Rubbing and scratching of affected area
• Hide damage
• Usually affects the base of the tail, perineum and udder in cattle
• Usually found on legs of sheep
• In goats, affects lower hindlegs, hindquarters and abdomen

Horses

• Induce crusty skin and lesions on the pastern, fetlock and cannon regions
• Often seen in rough-legged horses with heavy feathering
• Stamping, rubbing or biting of affected area
• Occurs more commonly in colder months
• Exudative proliferative dermatitis with secondary bacterial infection (greesy heels) can occur in severe cases
• Thickened, hairless skin in more severe cases