7.28 
SMALLPOX AMONG SHEEP IN WILTSHIRE. 
the disease never arose spontaneously. In the present in¬ 
stance, however, the introduction of the malady into the 
affected flock seemed pretty nigh impossible, at least highly 
improbable. No additions had been made to the flock from 
without, and no rams hired for two years. The disease could 
not have been imported by the shearers, as all the flocks they 
had worked among this year were known, and were ascer¬ 
tained to be and to have been free from the slightest symptom 
of the disease. No communication with the sheep of any 
strange flock, moreover, appeared to have or could well have 
taken place. But, most conclusive of all, it was not known 
that smallpox had occurred at all among the flocks of this 
country for several years. 
Smallpox (variola ovina) is a disease of very recent date 
among sheep in England. It first broke out in the vicinity 
of London, in the autumn of 1847. In 1848-49 and 1850 
the affection spread among the flocks of many counties, and 
caused immense losses. The origin of the malady, in this 
instance, could clearly be traced to the importation of several 
infected sheep from the continent, where it has long prevailed, 
more or less, and is never, perhaps, entirely absent from the 
wide district from which sheep are brought for our markets. 
The disease first declared itself in a small flock of sheep which 
had been imported, and sold to different purchasers in Smith- 
field Market. From these sheep, and others imported about 
the same time, all doubtless coming from an infected district 
of the continent, and many of which were seized with small¬ 
pox within a fortnight after landing, the disease was derived, 
and spread to our own flocks. Notwithstanding, however, 
the formidable nature and wide extent of the epizootic which 
followed, since 1853 (according to the writer of the article on 
“ Sheep” in Morton’s e Cyclopaedia of Agriculture 5 ) the 
affection has disappeared. Hence the recent outbreak of 
smallpox in the flocks at Allington would appear to be in¬ 
volved in mystery; and from the asserted improbability of its 
importation from a foreign source, and the absence of all 
evidence whatever of the existence of the malady as a sporadic 
affection among our own flocks, it would seem as if the con¬ 
clusion were almost forced upon us that the outbreak may 
have arisen spontaneously. “ Hitherto, 55 writes Professor 
Simonds,* “ we have regarded smallpox as spreading only 
by contagion; now we must ask whether it can have a spon¬ 
taneous origin? If the latter, no flock is safe, nor any part 
of the country secure. That which has occurred in Wiltshire 
may happen to-morrow in Sussex, and the next day in the 
midland counties. Having been consulted on the discovery 
* ‘Veterinarian/ September, 1862, p. 586. 
