Rickets associated with vitamin D deficiency in young sheep.

An outbreak of rickets in sheep under a year old (hoggs) appeared clinically as stiffness and rotation of the carpal joints. Histological studies confirmed the diagnosis and biochemical analyses of blood demonstrated a primary vitamin D deficiency.

Border disease without nervous signs or fleece changes.

A natural infection with border disease virus occurred in a flock on low ground in Argyll in the spring of 1984. The outbreak was unusual in that the typical clinical signs of border disease, ie, tremor and, or, fleece changes were not present; manifestations of disease were restricted to abortion and the birth of small weak lambs. The disease was shown to have been introduced to the flock by four healthy ewes persistently infected with border disease virus among a group of 39 purchased in October 1983. Further investigations in late August 1984 detected viraemia in six of seven ill-thriven lambs and four of 24 apparently healthy lambs. Attempted 'natural vaccination' of susceptible sheep by mixing them at grass for three months with groups of ewes and lambs known to contain virus excretors was largely unsuccessful as only four of 22 'sentinel' sheep seroconverted. In October 1984 the persistently infected purchased animals and all that year's lamb crop were removed from the farm. No disease occurred in 1985 when the lambing percentage was 129 per cent compared with 100 per cent in 1984. Two of the four persistently infected purchased ewes were mated at Moredun Research Institute in December 1984 and both produced healthy but persistently infected lambs.

Prevalence of herpesvirus infection in British red deer and investigations of further disease outbreaks.

A serological survey of the prevalence of a new herpesvirus isolated from red deer (Cervus elaphus), tentatively designated herpesvirus of Cervidae type 1 (HVC-1), has shown that the virus is widespread in free-living and farmed red deer. Neutralising antibodies were detected in hill deer culled at three different locations in the north of Scotland, in farmed deer on five of eight Scottish farms and in four of 12 groups of English farmed or park deer. Fifty-eight of 145 (40 per cent) hill deer, 67 of 203 (33 per cent) Scottish farmed deer and 26 of 172 (14 per cent) English deer had antibody, the overall prevalence being 29 per cent. Further outbreaks of ocular disease in farmed red deer calves caused by HVC-1 were investigated. Deer sent to an auction from one farm were found after sale to have been incubating the disease and it was thus spread to seven deer farms. Despite a high incidence of clinical disease in the calves from the original farm, few in-contact deer showed clinical signs.

Prolonged gestation in sheep in western Scotland associated with diffuse neuronal necrosis of the fetal central nervous system.

A specific disorder of sheep resulting in gestation periods extending up to eight months is reported for the first time. The condition, which is of low prevalence, occurs on hill farms in coastal regions of western Scotland and affected ewes usually die unless relieved of their fetuses by surgery. The fetuses may weigh up to 12 kg and have long hairy coats, skeletal deformities, precocious gonadal development and extensive liquefaction of central nervous system tissue. The aetiology has not been determined but some mechanisms which may be involved in the pathogenesis are discussed.

Systemic mycosis in Scottish red deer (Cervus elaphus).

The pathological features of 10 cases of systemic infection of young red deer by fungi morphologically identified as phycomycetes are described. The most frequently affected organs were the kidneys, followed by liver and central nervous system. The fungi stimulated an acute pyogenic inflammatory reaction and a phagocytic giant cell response. Vasculitis with thrombosis and spread of fungi to the surrounding tissue was a common finding. Culture was attempted in 4 cases; one yielded Absidia, 2 Aspergillus and the other an unidentified fungal growth. Analysis of the histories suggests that, in nine of the ten cases, stressful husbandry may have been a predisposing factor.

Ataxia/paresis syndrome of sheep in West Africa associated with bilateral multifocal cerebrospinal poliomalacia.

Between 1976 and 1981 a specific neurological disorder of sheep was observed in Ghana. It was encountered on eight properties on some of which it was responsible for losses of up to 72 per cent of the sheep stock in some years. The condition affected mainly adult ewes, and was characterised clinically by a brief period of ataxia, followed by paresis prostration and death in four to five days. Morphological examination of nine affected animals revealed significant lesions only in the central nervous system. These consisted of oedema of the intracellular glial compartment and bilateral, sometimes symmetrical, foci of spongy transformation, malacia and haemorrhage in the grey matter of the brain stem, cerebellum and spinal cord. The aetiology of ataxia/paresis syndrome was not determined but some possibilities are discussed in the context of other naturally occurring and experimental focal malacic disorders in animals.