ARCHIVE: Sheep pox

If you suspect signs of any notifiable disease, you must immediately notify a Defra Divisional Veterinary Manager.

Introduction

Sheep pox, a contagious disease caused by a virus, affects sheep and, occasionally, goats.

History and spread of the disease

Sheep pox is widely distributed in Asia and North and East Africa. Sheep pox first appeared in Great Britain in 1847, in a flock of imported sheep, and the last outbreak in this country was in 1866. Most of Europe and the Americas are now free from endemic sheep pox, although the disease occurred in Greece in 2000. Transfer of sheep pox among flocks and between countries occurs from the movement of sheep as appears to happen frequently in the countries of the Middle East.

Clinical signs

Sometimes the disease runs a very rapid course, which ends fatally in a few days. This form of the disease is seen mostly in lambs. The chief symptoms are those of fever and paralysis. An eruption in the form of red spots appears on the membranes of the eyes and nose, and on the wool-free parts of the skin. In older sheep the disease begins by signs of serious ill-health, notably a high temperature and surpressed appetite. An eruption appears on the mucous membranes of the nose, eyes and mouth, and as noted above on the wool-free parts of the skin - inside the thighs and elbows, under the belly, on the scrotum or the udder. The eruption may, however, also appear on the parts of the body covered by wool. On the wool-free regions it shows itself first in the form of small pimples, which may grow in size until their bases are 10mm or more in diameter. The larger pimples are flattened on the surface, and the skin around the base is reddened. A thick reddish- yellow discharge oozes from the pimples, and forms a yellow crust on the surface. Affected pregnant ewes often abort.

Affected sheep appear depressed although they may continue to eat unless prevented by mouth lesions. Pneumonia may result from bacterial infection The animal my also suffer respiratory problems. Photos of clinical signs...

Post-mortem

The above-described eruption occurs on the skin. The membrane of the throat is inflamed, and sometimes ulcerated. The covering membrane of the lungs shows red spots on its surface. Solid grey patches often appear on the lung substance. The cavities of the chest, heart sac and abdomen contain a reddish coloured fluid. The intestinal membrane is sometimes inflamed in patches. The kidneys often show grey patches under the capsule.

Legislation

Although sheep pox has not occurred in Great Britain for almost 150 years, various Orders for its control were made, the last one being the Sheep Pox Order of 1938. This Order was finally revoked in 1992. The legislation covering sheep pox, and a number of other diseases not present in this country, is now:

This legislation also covers Goat Pox.

This legislation extends the definition of "disease" in section 88 of the Animal Health Act 1981 to include the above diseases, and applies section 32 of the Act, which enables the Secretary of State to cause animals to be slaughtered on account of disease, to apply to these diseases.

The legislation does not make provision for:

i) infected premises, (ii) infected area, (iii) Other Control Measures, (iv) Minimum Duration of Controls, or (v) Compensation. Should there be an outbreak of sheep pox in this country, clearly legislation providing for these items would have to be put in place. Should the Secretary of State require the slaughter of any animal on account of sheep pox, arrangements would then
be made to determine the amount of compensation to be paid to the owner.

EU Legislation

Council Directive 82/894 (Link to EU website), as amended by Commission Decisions 95/1 and 00/556, makes Sheep and Goat Pox (capripox) compulsorily notifiable within the Community. Council Directive 92/119 does provide that certain specified Diseases, including Sheep and Goat Pox (capripox) shall be subject to compulsory slaughter, and the imposition of 3km protection zone and a 10km surveillance zone around premises where disease is confirmed. Restrictions would remain in force a minimum of 21 days, this being the incubation period of the disease.

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Page last modified: December 17, 2009