FACIAL ECZEMA

Wairarapa Times-Age, 10 May 1938, Page 3

FACIAL ECZEMA

OBSERVATIONS ON RECENT OUTBREAK LINCOLN COLLEGE REPORT Mr D. J. Sidey, of Lincoln College staff, referring to the recent outbreak of facial eczema among stock states: — The trouble is apparently due to a combination of circumstances. The skin has to be in a sensitive state and the animal is usually in an unhealthy and unthrifty state, mineral deficiency is usually in evidence, and serious outbreaks usually occur when there has been a dry period followed by rain, mild conditions, and a flush of growth. It is not infectious, like some other somewhat similar conditions, e.g., scabby mouth (fustular dermatitis), with which it might be confused. At least some of the outbreaks in the South Island have been associated with sheep eating a weed called St John’s Wort. This plant contains a substance which causes unpigmented skin to be photosensitivised, i.e., predisposed to the effect of the ultra-violet rays of the sun. It is characteristic of of trouble in sheep that pigmented skin, e.g., the coloured face of the Southdown, is not affected, while white-faced sheep are affected. In the case of cattle this does not always hold true.

The trouble under North Island conditions is worst where the grass is long, rank and damp. These conditions probably predispose to the skin round the mouth becoming irritated and more susceptible to any effect of the sun’s rays. In addition such feed conditions are not satisfactory for the health and well-being of the sheep, as has been previously pointed out in these columns in connection with some of the sheep losses in Canterbury, particularly in lamb losses in late summer from entero-toxaemia. Like these losses, facial eczema can at least be considerably reduced by the judicious feeding of dry feed as soon as it is realised that feed conditions are abnormal.

Good management could do much to minimise the trouble and this is only another case of the value to stock owners of a study of feed and climatic conditions. They should make preparations to forestall the possible effects of a feed supply which, while it may appear satisfactory, is really unsatisfactory.

The fact must not be lost sight of that in sheep at least the presence of internal parasites,- by causing a form of anaemia and reducing the vitality of the animals, may be a contributing factor to the deaths which occur in the more serious cases.