Sheep Information

Sheep Scab

Sheep scab is a skin disease of sheep caused by a mite called Psoroptes ovis. It is present in several sheep producing countries, including the UK. It causes severe itching in affected sheep if left untreated. Scaly lesions develop on the woolly parts of the body and sheep often bite themselves and rub against objects to relieve the irritation causing loss of wool. Untreated sheep may lose weight.

Maedi Visna (MV)

Maedi Visna (MV) is a disease of sheep present in most sheep producing countries, including GB. It is caused by a lentivirus. A closely related virus, Caprine Arthritis Encephalitis CAE), causes a similar disease in goats. The name of the disease is formed by the two Icelandic words that describe the clinical signs it produces – maedi (‘laboured breathing’ affecting the lungs) and visna (‘shrinking’ or ‘wasting’ affecting the central nervous system). The virus can infect sheep at any age, but signs of the disease are not usually seen until at least 3 years of age. These may include pneumonia, weight loss, joint problems, mastitis and nervous signs. In goats the main clinical sign of CAE is lameness. Weight loss and shrinkage of the udder may also be present. The nervous form of the disease occurs rarely and generally only in young kids. The disease spreads easily between sheep and can cause high economic losses. A MV/CAE accreditation scheme is run by the Scottish Agricultural College.

Urinary Calculi

A hard mass of mineral salts in the urinary tract caused by dietary imbalance; seen in male animals it causes blockage of the penis and subsequent death due to renal failure if not treated. The disease is most common in castrated males on a high cereal diet. The signs are restlessness, straining to urinate, pawing the ground, constantly looking at its own abdomen, vocal signs of pain.

Treatment involves surgery to remove the blocked penis and create a new opening for the urethra which is the tube that carries urine from the bladder to the outside.

Schmallenberg Virus

What is the Schmallenberg Virus?

The Schmallenberg virus is a newly emerging virus in the same family as the Akabane virus. Little is known about it, but new information is coming to light daily. As it is a new virus testing is still being developed and a vaccine is a long way off.

The virus appears to be spread by biting insects most likely midges (similar to bluetongue), however, direct transmission may also occur. Acording to Met office data there were 4-8 days in August to late October when infected midges could have been blown across the channel. Thus disease is emerging now but infection actually took place last year.

It appears that animals which are bitten by infected insects are highly likely to contract the disease, and subsequent insects biting this animal are highly likely to become infected themselves. Spread of the disease therefore is a lot quicker and easier than we have seen with bluetongue.

What does it do?

The clinical signs of Schmallenberg virus seem to primarily be seen in the foetus. These clinical signs consist of severe brain damage/deformities if infection occurs in the first third of pregnancy, limb deformities if infection occurs in the middle third of pregnancy, and brain problems presenting as depression, problems standing/balancing, and inability to suckle if infection occurs in the last third of pregnancy.

Infection in the animal usually has no symptoms at all, although in cattle it may present as diarrhoea, high temperature, and reduced milk yield.

Newborn animals that are affected may or may not be viable, whether the viable effected offspring are a disease risk to other animals is not known, it would be wise to separate any affected offspring with their dam, from the rest of the flock/herd.

At the present time infection has only been confirmed in sheep, but all ruminants are susceptible. Infection rates are variable, but up to 50% of offspring can be affected.

Can it infect humans?

Some viruses in the same family as this can infect humans but it seems Schmallenberg lacks the required genes. Having said this we would recommend women who are pregnant or hoping to become pregnant should not come into contact with ruminant animals, especially around lambing/calving/kidding.