12
is kept, and may run into many years. Loss of condition predisposes to other
diseases.
I have found camels in which no embryos could be discovered in the
blood, but which on post mortem showed dead degenerating adults in the
spermatic arteries and no living ones could be found anywhere ; these were
apparently cases of natural recovery.
On the other hand, several severe cases have been under observation for
long periods (one for 2½ years) but still show embryos in their blood, and
remain in miserable condition.
46. It has been found that in the Punjab, Filaria evansi is practically
(and I believe wholly) confined to camels which have spent part of their lives
in those parts of India lying west of the Indus. Large numbers were infected
in the Mohmand Expedition. I have examined hundreds of camels in investi-
gating this point, and have found (i) a large proportion of camels from the
Trans-Indus territory harbouring the worm, (ii) no case of filariasis in a camel
which has been bred and reared East of the Indus at a distance sufficient
to ensure its never having been across the river, and (iii) in spite of the high
proportion of filariasis in camels returning from the Mohmand Expedition in
June 1908, there has been no case found to date (two years) of the infection
having spread to remount camels from the east of the Indus. I conclude that
the unknown agent which spreads the infection is confined to places in Trans-
Indus territory. For the same reasons, it is unlikely that the transfer of the
embryos from one camel to another is mechanical or it would have been spread
from the expedition camels by the Punjab Tabanidæ.
The most likely explanation of the spread of filariasis is that the embryo
is removed from the circulation by some blood-sucking intermediary host in
which it undergoes some developmental process and then regains a camel either
by the proboscis of its intermediary host as in human filariasis or by its
excretion into the water-supply.
Some preliminary observations seem to exclude the Hippobosca camelina
from suspicion although that fly appears to be confined to parts of the Trans-
Indus.
47. A number of drugs have been tried in the treatment of seriously
affected cases ; these include salts of Antimony, Mercury and Strychnine, and
also Atoxyl, Soamin and Chloroform, but none have given a good result ;
castration, to remove some of the adult filariæ has been tried but the operation
is very unsatisfactory when practised on camels in poor condition, and in most
cases, adults are also found in other situations besides the artery of the testicle
and so remain unaffected by the operation.
48. Having been asked to advise preventive measures against filariasis
in the absence of exact knowledge of the agent of infection, I suggested :—
I. For camels east of the Indus no preventive measures are necessary.
II. For those west of Indus,
(i) in the cold weather when possible, water the camels from wells
or water the filaria camels from a separate source than the
healthy, or downstream of them ;
(ii) in the hot weather, in addition, segregate the filaria cases and do
not let the healthy share the same grazing area as the filaria
camels.
III. Surra is a far more important disease than filariasis and probably
the necessary precautions against the former will prevent the spread
of the latter to a great extent. A detailed account is being prepared
of Camel-Filariasis.
49. FILARIÆ OF THE EYE.—This is a new parasite and was found on 15th
May 1909 in the vitreous chamber of the eye of a camel and was the apparent
cause of the ophthalmia which affected the eye. (Case 1.)
The parasite was sent to Professor Raillet of Alfort Veterinary College,
Prance, who kindly examined it and reported it to be a new species which he
has named Thelazia leesei, and which he considered to belong to the same group
as Thelazia lachrymalis (better known as Filaria lachrymalis) of the ox.