F.
HOBDAY
97
is now extraordinarily small. It is, however, to the domestic pets, especial-
ly the dog and cat, that attention should be drawn, for it is quite an easy
matter for a pet dog to transmit the parasite of mange from itself to its owner.
An itchy dog should, therefore, always be regarded with suspicion, and the
pernicious habit of allowing a dog to sleep in bed with a human being should
be emphatically discouraged. A dog with mange, especially in hot weather,
or when its body becomes heated by lying in front of the fire (or sleeping on
an eider-down or blanket), will be continually scratching, especially in the
region of the arm-pits and under the thighs, where the body is hot and the hair
is thin. If no treatment is adopted, the dog will break out in sores, the hair
will fall off, and the animal will presently smell very offensively and become
covered with scabs. If allowed to come into contact with any part of the
human body for more than a few minutes, it is quite an easy matter for the
parasite to transfer itself to its human host, and it may remain for a considera-
able number of days, or even weeks, until it has finished its life-history. During
this time it will give rise to a great deal of irritation and discomfort, which
could easily have been prevented had the owner of the dog sought veteri-
nary advice.
There are numbers of other diseases in which it is of value to the Public
Health Service that, in the fight for their eradication, the human physician
and the veterinarian should collaborate, for the patients of each are equally
attacked. Cancer may be taken as a type. This dreaded disease is recognis-
ed in such veterinary patients as horses, cattle, dogs, cats and even fish,
and many of the theories which research workers form, if their observations
are concentrated on man alone, may at once be seen to be erroneous upon
comparing notes with veterinary pathologists, whose lives bring them in con-
tact with the comparative aspect. In foreign countries this has been for a
long time recognised, and their governments have granted liberal funds for
research into the problems of animal diseases and their relation to Public
Health, finding it a paying proposition—even if considered only from the
economic standpoint. Great Britain has been behindhand in this respect,
but during the past few years with the establishment of the Animal Research
Institute connected with the Royal Veterinary College, at Camden Town,
and of the Institute of Animal Pathology at Cambridge, together with the
creation of University Veterinary degrees and a Post-graduate Diploma of
Veterinary State Medicine, there is a good prospect that, long before another
decade has passed, the Government organisation of Veterinary Officers of
Health will have as important a, place in Public Health as is accorded to the
graduates of the human branch of State Medicine.
My list of those diseases which furnish valuable instruction in the epi-
demiology of animals and man is by no means complete, but I must in con-
clusion just allude to one other—namely, contagious abortion of cattle which
gives rise to Undulant Fever of man. That cases of transmission from the
cow do occur is generally admitted, but not as frequently as might be expect-
ed when one considers the great prevalence of this disease in milking cattle