A prion disease which causes brain lesions leading to wasting and abnormal movement after a prolonged incubation period. It is controlled by selecting animals of high genetic resistance. Although the scrapie agent has not been fully characterised it is known to be very resistant to all known disinfectants. The mode of transmission has also not been established though it is thought to be primarily spread at lambing, particularly to the lambs of ewes incubating the disease. Wherever possible, source sheep from flocks free of the disease - assurance of freedom may not always be reliable as flockmasters may not have confirmed diagnosis. The National Scrapie Plan is designed to identify rams genetically resistant to infection (Rls) and wherever possible only these rams should be purchased. Alternatively, the status of any ram stud can be established by a simple blood test.
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A bacterial disease that mainly causes abscesses in the glands of the head and neck. It is currently seen mainly in pedigree terminal sire flocks. The bacterium (Corynebacterium pseudotuberctilosis), can survive in the environment for several months and is highly infectious. For the disinfection of sheds and pens, 1 per cent chlorohexidine or calcium hypochlorite can be used. Bedding and topsoil from sheds and pens should be removed and the area disinfected with 20 per cent calcium hypochlorite. Shearing equipment should be dipped in strong disinfectant or chlorine bleach before and after use.

Establish if there is a history of abscesses when buying new stock. Thorough clinical examination at time of purchase is vital; look at the older rams and ewes for evidence of 'lumps and bumps" around the head and neck. Isolate all bought in sheep, including rams, until they are likely to be 'safe'. This means two months quarantine at least and even then, the presence of undetected and resolved lesions may remain a potential source of infection.

There is no vaccine currently available in the UK and antibiotics are not very effective. No individual animal test is available either but recently SAC have developed a flock test which looks very promising, If CLA is detected in the flock, infected animals should be separated, thus forming clean and dirty flocks. If uncertain, confine purchases to young animals preferably which have neither been shorn nor trough fed with older sheep.
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A slow viral infection causing disease in adult sheep, principally pneumonia with wasting. chronic mastitis and on rare occasions nervous symptoms. Likely to become far more prevalent unless vigilance is maintained. Most pedigree flocks are MV accredited. Although a recent survey has indicated that approximately 0.2% of non-pedigree sheep are infected, because of the long incubation period, single blood tests are not reliable on individual animals but more reliable on a flock basis. Therefore sheep are best sourced from MV accredited flocks. For further advice consult SAC's Sheep and Goat Health Schemes (Tel: 01463 226995). Further information on this disease can also be found in Moredun Foundation newsheet Volume 2 Number 12.
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Another slow virus disease producing cancerous changes in the lungs. As the tumour grows and spreads within the lungs, it displaces healthy lung tissue and interferes with normal breathing. The result is a chronic pneumonia which is not affected by antibiotic treatment. The disease also makes affected sheep more susceptible to pasteurellosis. Because the tumour is formed from fluid-producing cells, this fluid accumulates in the lungs and the breathing becomes noisy due to air bubbling through the fluid. In advanced cases, when the affected sheep is raised by its hind legs so that its head is lower than its chest, a frothy fluid will flow from its nostrils. At the moment there are no flock or individual tests but recent research at Moredun raises hopes for a test in the future. Further information on this disease can be found in Moredun Foundation newsheet Volume 1 Number 15.
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A liver parasite which requires a fresh water snail as an intermediate host to maintain its life cycle. The warmer wetter summers that have been a marked feature of recent years offer favourable climatic conditions both for the snails and the development of the larval stages. Although the parasite takes 12 weeks to mature within the sheep and begin to lay eggs, the developing larval stages also cause significant damage before they become adults. Reports of disease attributable to liver fluke have increased as the disease has spread into areas which have been unaffected for a long time. For these reasons sheep purchased from fluke endemic areas may need to be treated on arrival at the farni. If fluke is suspected in permanent stock dose with a flukicide such as triclabendazole, which kills ail stages of the parasite in the autumn and again early in the New year. Further information on this disease can be found in Moredun Foundation newsheet Volume 1 Number 4
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Ticks are important in some areas. Ticks transmit three main diseases - Tick Borne Fever (TBF), Tick pyaemia and louping ill. The main danger lies in moving naive sheep onto tick infested pastures, particularly if they are pregnant, as TBF can cause abortion. Exposure to ticks prior to breeding should afford protection against TBF. Appropriate prevention in lambs reduces tick pyaerma.

Wherever possible sheep to be introduced to farms with ticks should be sourced from similar properties with ticks. If this is not possible do not introduce naive rams at tupping as TBF may cause temporary infertility. If you have louping ill on your property all introduced animals should be vaccinated to avoid serious losses. All sheep from areas where ticks are present should be treated with an appropriate insecticide because ticks can introduce new diseases or strains to the flock.
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This is a chronic gut disease of cattle, sheep, goats and deer, resulting in diarrhoea, weight loss and eventually death. The disease is caused by a bacterium called Mycobacterium avium subspecies paratuberculosis (referred to as Map) which can survive for long periods of time in the environment. Little is known of its incidence and distribution in the UK. Animals are usually infected with Map in the first few weeks after birth but do not develop clinical disease until they are 18 months or older. Animals in the long 'subclinical' stage of infection are particularly difficult to diagnose. Diagnosis depends on three methods, blood tests, culture of Map, and post mortem examination. These tests are difficult, expensive and time consuming.

There is no effective treatment for paratuberculosis. Affected animals are a source of infection to other stock and should be euthanased as soon as possible after diagnosis. Avoid purchasing from flocks which have a high level of wasting culls (not easy to establish!) as this may be an indication that they have a residual Johne's infection. Further information on this disease can be found in Moredun Foundation newsheet Volume 3 Number 9.
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Consider the abortion status of your flock as well as that of the potential vendor's. Certain infections are passed from animal to animal (Chlamidia psittaci) and Border Disease virus. Others are picked up from the environment (Toxoplasma gondii, Campylobacter). Buying in animals that are not yet pregnant would normally exclude the possibility of importing the former but might leave the buyer open to bringing in the latter infections. Purchase of pregnant stock opens up the risk of bringing in both types of infection. For replacement of female breeding animals in a flock in which there is no serious infection, sheep are best purchased directly from a source known to be free of infectious abortion. When animals are from an unknown source then it is very much safer for them to be mated and maintained away from the main flock until after lambing.

Flocks in the Premium Health Scheme run by the SAC are considered to be free of the risk of chlamyclial abortion. If however, chlamyclial abortion is established in the home flock then all newcomers should he vaccinated appropriately before being allowed to mix with them.

If Border Disease is present in the home flock then newly bought in animals might contract infection and go on to abort in a subsequent lambing. If replacement stock are mixed with the main flock for several weeks before mating then infection and immunity would be given a chance to establish before pregnancy. Rams should ideally be tested for Border Disease infection before being introduced to the flock.
In the case of Campylobacter abortion it can be minimized if, following the 21 day quarantine, incoming breeding sheep are mixed with the resident flock for as long as possible before they go to the ram. This allows them to acquire infection before they are mated and thus develop protective antibodies before the risk period of pregnancy.

This is not a complete list of all the potential diseases that can be introduced when sheep are purchased. Avoidance of purchasing sheep from flocks in which these diseases are present will help in the establishment of a healthy flock.

It is therefore a good policy to visit and discuss with the vendor any problems they may have experienced. In addition the granting of permission to discuss the flock's health with the vendor's veterinary surgeon probably means there is little to hide.

As is always the case teeth, feet, the udders of ewes and the reproductive organs of rams should be closely examined.
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