46 
WARBLE FLY. 
Methods of destroying the Warble-maggot in the Hide. 
When the warble-swelling has “ ripened,” as it is called (that is, 
has opened so that the two black specks at the end of the tail of the 
maggot are visible), then it can be destroyed easily and cheaply by so 
many kinds of applications, or kinds of treatment, that it is difficult 
to arrange them in some sort of order for reference. 
Where the maggot can be squeezed out, this is probably the very 
best plan of all. The grub is thus cleared out bodily, —quite got rid 
of,—the filthy fluid in the hole oozes out, the cavity draws together in 
somewhere about three weeks (where we have the date of healing 
given), and, excepting that the false skin (see p. 13) remains for a 
while in the opening, and that there will always be more or less of a 
scar or injured condition of the spot, the work is complete. But it is 
not always possible to manage this squeezing out; the maggot may 
not be advanced enough to come away, and later on, where attack is 
bad, the back may be too sore to bear handling. 
Bor such conditions, dressings or applications to the entrance-hole 
of the warble are needed, and all that is wanted is something that will 
stifle the maggot by choking up the breathing-pores at the end of its 
tail, or that will poison it by running down into the warble-cell where 
the maggot is lying mouth-end downward, and, mixing with the fluid 
which it sucks in, thus poison it. 
Amongst the many applications of which we have notes of success 
on sound authority, I think the only really poisonous one advised is 
mercurial ointment, and observations have been sent in, of which 
several are given below, of the safe and successful use of mercurial 
ointment for killing the maggot in the warble from various cattle- 
owners and others who have used it up to the amount of application 
to 250 head in a herd of 800 cattle. 
In these cases the ointment has been used in the manner I have 
always most carefully advised, namely, only as a small touch on the 
opening of the warble. By no means as a large dab, nor as a smear, 
nor (where warbles were gradually appearing or were numerous) 
as an application to be made repeatedly over a large surface of warbled 
hide.* 
The first communication on this subject was sent me from Mr. B. 
Stratton, of The Duffryn, Newport, Mon., on April 11th, 1884, with a 
few remarks on some other remedies :— 
“ I have treated some warbles with acetic acid, some with tar, and 
* Only one instance has ever been reported to me of ill effects, and in this case 
the ointment was not applied according to directions, but the animal, which was 
suffering to a quite unusual extent from warbles, was smeared along from head to 
tail. Details, comments, and opinions thereon will be found in the ‘ Agricultural 
Gazette,’ Nos. 598, 599, and 601 (1885). 
