Raw hide and skin defects caused by insects

Damages caused by the warble fly
Larvae of the warble fly which result from the bite of the warble fly which eat their way from inside the animal through the skin, producing open or scarred holes, the so-called warble marks. Control is by mechanically removing eggs and larvae, treatment with special phosphoric esters or contact insecticides.
Defects caused by awns
Parasites which lodges in the hair coat and can destroy the skin down to the corium.
Defects caused by lice
Injuries caused by infestation with blood-sucking lice, with partial destruction of the grain layer.
Defects caused by mites (mange, scabies)
Parasitic hair follicle mites who invade cattle, goats and sheep, but also pig and dogs. They cause recessions or holes with formation of pustules in the grain tissue. Can be avoided by clean indoor livestock husbandry.
damage caused by dust mite 
This insect also casued grain damge of hide and skin
Insect bites and stings can cause an immediate skin reaction. The bite from fire ants and the sting from bees, wasps, and hornets are usually painful. Bites caused by mosquitoes, fleas, and mites are more likely to cause itching than pain.

Overview & Considerations 

In most cases, bites and stings can be easily treated at home. However, some people have a severe allergic reaction to insect bites and stings. This is a life-threatening allergic reaction known as anaphylaxis, and it requires urgent emergency care. Severe reactions can affect the whole body and may occur very quickly, often within minutes. These severe reactions can be rapidly fatal if untreated. Call 911 if you are with someone who has chest pain, face or mouth swelling, difficulty swallowing, trouble breathing, or goes into shock.
Some spider bites, like those of the black widow or brown recluse, are also serious and can be life-threatening. Most spider bites, however, are harmless. If bitten by an insect or spider, bring it for identification if this can be done quickly and safely.Defects caused by diseases injuries or infection
Cockle
Formation of nodules on the grain of sheep skins, mostly in the neck or shoulder area, spot-like deposits of fat, mostly as result of fattening; may also be caused by parasites.
Eczemas
More or less pronounced scale formation on the hair side of the skin which may completely destroy the grain.
Skin diseases
Called dermatomycoses or cattle ringworm, subdivided into Microsporia and Trichophyton infection.
Microsporia infection
Skin defect caused by trichomycetes which damages the grain surface by the formation of pinholes.