ABSCESS, 108 
But at what time must it be made? Generally, one should wait until 
the abscessis ripe. If the puncture is made when the pus is not yet 
entirely gathered, secondary centers may form in the inflamed zone and 
impose other interferences, 
Numerous cases are observed, however, where the veterinarian is 
obliged to make the premature opening of purulent collections, When 
these are deeply situated, under aponeutotic fasciz or in the neighbor- 
hood of a splanchnic cavity, of a synovial or tendinous sheath, or close 
to a large blood vessel, a bone, a tendon, a ligamentous cord or the 
fibro-cartilages of the foot, then they must be opened at once, if serious 
complications are to be avoided. The attractive theory of the constant 
tendency of pus to progress towards the tegumentary surfaces has seen 
its days. Examples are not rare of inflammations of the great serous 
membranes, of articulations, or of necrosis of organs with dull nutrition, 
induced by abscesses, the lancing of which had been too long delayed 
Thus, salivary, stercoral and urinary abscesses, where numerous bac- 
teriz will unite to bring on gangrenous or septic accidents, should be 
lanced at once. Also, purulent collections, in regions where they may 
interfere with the execution of important functions, must be opened as 
soon as they are recognized by sure signs. In this place, we may 
mention especially the sub-parotid abscesses which interfere with 
deglutition or respiration ; those developed in the pelvis, which com- 
press the rectum ; those of the scrotal region, which may close up the 
sheath, prevent erection and interfere with micturation. In case of 
the horse, the same rule is to be observed for abcesses of the digital 
region, and for purulent gatherings under the hoof: the former have at 
times arapid development; under the cutaneous chorion, which is very 
resisting, the pus spreads, gives rise to excessive pains, macerates the 
tendons, fibro-cartilages, and the bones, and sometimes reaches one 
of the phalangeal joints ; the latter, unable to make their way through 
the horny covering, rapidly separate it from its tegumentary membrane 
underneath, and, before escaping at the coronet, produce in the tissues 
of the foot most serious disorders, At this point, we may understand 
that phlegmons vary as to gravity, and spread more or less rapidly, 
according to the microbic species which has caused them. Ordinarily, 
those originating from streptococci are more diffused and affect more 
the lymphatics than those due to staphylococci. 
Abscesses may be opened with the distoury, trosar, or with the cautery. 
The: straight bistoury is most commonly used to lance abscesses. 
The sharp edge of the instrument should be turned upwards or down- 
wards, as the case may be; the thumb and index, resting on the sides 
of the blade, more or less close to the point, according to the depth of 
the cavity to be opened, should limit the introduction of the blade. A 
narrow incision is sufficient for superficial abscesses ; if they are large, 
