TAPPING THE PERICARDIUM IN THE DOG. 
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grows small, fugitive, and weak, sometimes almost imperceptible and 
uncountable. 
Compression of the auricles—the portions of the heart which 
collapse most readily—impedes the flow of blood, produces cyanosis, 
venous pulse in the jugulars, and mechanical dyspnoea owing to 
stasis of blood in the lungs. The symptoms of oppression at first seen 
are undoubtedly of reflex origin, due to the pain in the inflamed 
pericardium. 
If not treated, acute pericarditis may rapidly lead to death, some¬ 
times in less than a week. It may also (though exceptionally) terminate 
in recovery, the exudate becoming reabsorbed, the symptoms gradually 
diminishing and finally disappearing. In certain cases it assumes 
the chronic form. 
The variety of pericarditis to which the term haemorrhagic has been 
applied is characterised by a reddish, sanguineous exudate, and occurs 
somewhat frequently in the dog. It is not infrequently of tuberculous 
origin, and is always very grave in character. 
In general, when the veterinary surgeon is called on to examine a 
dog affected with exudative pericarditis, the disease has already been in 
existence for some time, occasionally for several weeks; and, provided 
he makes a complete examination of the patient, and does not 
forget the heart, a careful consideration of the signs furnished by 
palpation, percussion, and auscultation should enable him to arrive at a 
correct diagnosis. Ascites is often the most striking symptom, and 
puts one on the right path. It is usually easy to differentiate between 
pericarditis and pleurisy. In pleurisy with moderate exudation, 
resembling that of pericarditis, the zone of dulness changes with the 
animal’s position. By standing the animal on its hind legs the heart- 
sounds and vesicular murmur become readily perceptible, while the 
upper part of the thorax is resonant; in the normal standing position 
the resonance disappears or becomes dulled. 
When, despite treatment, the exudate increases and the symptoms 
become more marked and alarming, or when even on first examination 
the general condition appears dangerous, the pericardium can be 
punctured. 
Operation is as follows:—The precordial region is prepared by 
clipping away the hair, and shaving the skin a little below the centre of 
the zone of dulness for a distance of two or three square inches. The 
parts are afterwards washed with alcohol, and with a *1 per cent, 
solution of sublimate. The aspirator is provided with an indiarubber 
tube. The air being exhausted from the cylinder of the aspirator, the 
instrument is passed to an assistant; the point of the needle is then 
introduced at the centre of the prepared surface, through the fifth 
