Maedi Visna
Maedi Visna (MV) is a chronic viral disease which occurs in most sheep producing countries and has been in Britain for approximately 20 years. The disease was originally brought into this country by sheep imported from the continent. It is estimated that at least 100,000 sheep are now infected in the national flock and clinical outbreaks are being reported from all over the country.

MV infects sheep at any age but the clinical signs of the disease are usually not seen for at least 3 years.

• Pneumonia
• Progressive paralysis
• Wasting
• Arthritis
• Chronic mastitis

MV is highly contagious and mainly spread via by colostrum or milk from infected ewes. It can also be spread by close contact via virus shed in body fluids or transfer of blood from needles and equipment . Diagnosis is by blood testing or post mortem. There is no treatment and no vaccine.

The SAC run monitoring and accreditation schemes.

Caprine Arthritis / Encephalitis (CAE)
CAE is a chronic viral disease closely related to MV in sheep. The level of infection in the UK is thought be less than 2% as many goat keepers have been rigorously testing to eradicate it.

Goats are usually infected as a kid and can be symptomless carriers for life. Clinical symptoms are usually only seen in adult goats.

• Arthritis
• Hard udder
• Pneumonia
• Neurological signs
• Weight loss

The main spread of disease is by colostrum or milk of infected does. It can also be spread by close contact via virus shed in body fluids or transfer of blood via needles and equipment. The virus doesn’t survive very long in the environment.
Diagnosis is usually by blood testing or post mortem. There is no treatment or vaccine.

The SAC run a CAE accreditation scheme.

Caseous Lymphadenitis
Caseous Lymphadenitis (CLA) is contagious bacterial disease caused by Corynebacterium pseudotuberculosis, which leads to the formation of abscesses around the body of the affected animal. Over the last three years the Veterinary Investigation Services in Britain have recorded almost 250 outbreaks in sheep flocks. Although it is not yet a common disease in this country, it is no longer a rare one. The disease is now present in all parts of the country, with the condition still being most common within the terminal sire breeds of sheep. Like MV it was brought into the county in imported animals.

Usually the only clinical signs are the development of superficial abscesses which are often associated with lymph nodes. CLA is spread via contamination of skin wounds i.e. after shearing or after rams fighting. Confirmation of disease is by culture of abscess contents or blood sampling. There is no treatment. There is no vaccine in this country but we can obtain a vaccine by special licence from Australia if necessary.

The SAC run a monitoring scheme.

Scrapie
Scrapie is a fatal brain disease of sheep and goats which has been recognised in the British sheep flock since 1732. It has only recently become important in the aftermath of the BSE crisis. Scrapie is a notifiable disease and positive animals must be culled.

Clinical signs do not usually appear until animals are over 3 years of age, and can be subtle and difficult to spot in the early stages.

• Skin irritation
• Behavioural changes
• Changes in posture and gait
• Weight loss
• Death

Breeding for resistance to scrapie is underway with Defra’s National Scrapie Plan.

Abortions
For the best chance of diagnosing abortions, both the fresh aborted foetus and the placenta are required. Either bring them to us at the surgery or take them direct to your local VLA centre (Starcross or Polwhele)

Chlamydia (Enzootic) and Toxoplasmosis are still the two most common causes of abortion in sheep despite there being cheap and effective vaccines. We have two subsidised testing schemes available if you are having abortion problems in your flock to determine which vaccine would be appropriate.

1. Barren Ewe Check (Jan – Apr). Blood sampling of ewes that are found to be empty at scanning.
2. Flock Check (Mar – Jul). Blood sampling ewes that have aborted or are barren at the end of the lambing season.

Please contact your local surgery to arrange a visit and testing.

The SAC run a premium health scheme to enable flocks to become accredited as free of Enzootic abortion (EAE).

Accreditation Schemes:

• SAC Premium Health Scheme (Enzootic abortion)
• SAC MV / CAE Accreditation Scheme
• SAC MV Monitoring Scheme
• SAC CLA Monitoring Scheme
• National Scrapie Plan (Defra)

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