Brandsiekte
By Dr Mackie Hobson BSc(Agric),BVSc

‘Brandsiekte’  Sheep Scab and Angora goats

 DOES NOT affect ANGORA GOATS.

Angora goats must however be considered to be potential mechanical vector in the same way clothing, vehicles and shears may introduce the mite to a farm and hence the importance of bio-security.

Sheep-scab, psoroptic mange, “scab”, “brandsiekte” is caused by a mite Psoroptes ovis . Found in all provinces, but especially in Free State and Eastern Cape, it spreads easily and is a controlled disease.

Trials ( Meinties, Fourie, Horak) demonstrated that Angora and Boer goats do not develop lesions from sheep scab mites and did not harbour the mites.

Sheep-scab is more likely to occur in autumn and winter, and infection comes from contact with other sheep that have scab. These infected sheep pass on the mites when introduced to your flock.

Alternatively, since mites can survive for up to 10-17 days after dropping off the host or in wool stuck on fences,trucks where the sheep have rubbed themselves they can crawl onto your sheep.

Clinical signs:

The mites prefer areas covered with wool, particularly on the sides of the sheep. In haired breeds, they tend to occur on the tails and backs and don’t show the ‘normal’ signs of scab. The first signs may appear 5 days after infection.

After piercing the skin, the mites suck body fluid from the tissue below the skin. Fluid leaks from the skin and dries to form yellow scabs – which is why the condition is called “scab”.

So look for sheep biting themselves and rubbing against fences and other objects. You’ll also see wool in the animal’s mouth, or on fences and other objects the sheep’s rubbed itself against. If you inspect the sheep carefully you may feel very small lumps on the skin.

You’ll also see bare, scabby patches of skin and matted wool. Bare patches will get larger as the mite numbers increase. Left untreated, sheep can become thin and weak, and may eventually die.

Treatment:

If you suspect the presence of sheep-scab, contact your local animal technician or state vet immediately. You should also tell your neighbours so that they can treat their own sheep.

Chemicals that kill the sheep-scab mite are used for treatment and control. The state vet will inform you as to which product you must use although there are a number of registered products. (See Ectoparasite drug list under the drug list on ‘vet’s corner’. All sheep in the flock need to be treated at the same time, or else mites from untreated sheep can later infest treated animals.

 Sheep must be treated TWICE 8-10 days apart as eggs may hatch during this period.

Control/Prevention

1: Prevent direct transmission

All sheep must be treated at the same time (preferably districts at a time rather than individual farms

.

• Good fences
• Good neighbour communication
• Strict biosecurity of introduced sheep, and rams (see article on biosecurity). Keep new separate for a month.
• Treat bought sheep
• If take sheep to show, quarantine on return/treat
• If your sheep are scratching get the cause diagnosed
• Current legislation states that all stock should be treated/dipped every year. This includes goats where sheep are also farmed.

2: Prevent indirect transmission

The mite can survive for 17 days off sheep so it is important to:

• Shearing teams, supply clean overalls or place in dip for 15 min, all items(brooms, shears washed with dip)
• Kraals, sales must be left empty for 17 days so no mites survive.
• Trucks cleaned before loading your stock

 OTHER MITES:

Psoroptes cuniculi (Ear Mange) does occur in Angora goats but it is NOT ‘brandsiekte’. This mite usually affects the ears but can spread to the head, neck, and body and cause severe irritation. This occurs particularly in Angora goats, in which the mohair is considerably damaged. Although the course is chronic, the prognosis is good. Any of the acaricides approved for use in sheep will eliminate P cuniculi in goats. Lactating dairy goats should be treated only with lime-sulfur solution.

Psorergatic Mange (Itch Mite, Australian Itch)

Psorergates ovis is a common skin mite of sheep in many parts of the world.

Demodectic Mange

This has been reported in sheep (Demodex ovis) and goats (D caprae), in which it causes non-pruritic papules and nodules in goats, especially over the face, neck, shoulders, and sides. The nodules contain a thick, waxy, grayish material that can be easily expressed.

Chorioptic Mange

Chorioptes caprae can occur in goats. Papules and crusts are seen on the feet and legs.