Lesions occur most often on the lower limbs, the muzzle, face and neck. The clinical signs and symptoms of trombiculiasis include pruritis, hives, papules, scabs and crust. Occasionally the larvae can be identified at the centre of a lesion as an orange-red, six legged organisms that are barely visible to the naked eye.
Diagnosis can be made from clinical signs and symptoms and from skin biopsy that demonstrates and larva.
Generally, no treatment is required as the larvae detach themselves after 7-10 days of feeding. Pyrethrin may be used to kill any remaining larva. Corticosteroid use & lime sulphur can be used for symptomatic relief.
Preventative measures such as the spraying of pesticides and insect repellents may reduce the incidence of trombiculiasis, but these measures may also make pastures unsuitable for grazing.
Chorioptic Mange Chorioptic mange is commonly referred to as
or “chorioptic acariasis”.
Chorioptic mange is caused by a type of mite called Chorioptes bovis . These mites live on the surface of the skin, in the hair, and feed off of skin debris and the fluids of the epidermis causing local inflammation. breeds as they tend to have heavy feathers on the distal limbs. The incidence of chorioptic mange also increases in cold weather and in those horses that are not thoroughly groomed. It affects the distal limbs, especially the hind limbs. Chorioptic mange is seen most commonly in Clinically chorioptic mange presents as intense pruritis, scale and crust that causes the horse to itch and bite at the distal limbs. This causes excoriation and alopecia in affected areas. Horse will kick, stomp & bite at the legs. Lichenification of the palmar aspect of the pastern is seen if the infestation is severe or prolonged. Lichenification causes the skin to appear to have transverse folds in the pastern region.
Diagnosis is made through clinical signs and symptoms as well as by the isolation of mite eggs in skin scrapings taken from affected areas.
The recommended treatment is the removal of excess hair from affected areas and the topical application of insecticides or hot lime sulphur.
Chorioptic mange is the most common mange affecting horses though it is not considered a common disease in horses.
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