DISEASES OF THE LUNGS 5 



CONGESTION OF THE LUNGS 



Definition. By congestion of the lungs is meant an undue fulness or 

 engorgement of the pulmonary vessels with blood, and especially those 

 concerned with respiration as distinguished from others engaged in the 

 nutrition of the organs. It is convenient to consider this disease under 

 two headings A, as acute, and B, as passive or mechanical congestion. 

 The acute form of the affection is most frequently met with in horses sub- 

 jected to severe exertion and distress. In the second form it arises in the 

 course of various forms of disease, and especially obstructive heart disease. 

 It is also a frequent and fatal accompaniment of the specific fevers, and 

 may complicate acute inflammation of many of the organs of the body. 



Causes. Congestion of the lungs follows upon a variety of disturb- 

 ances in the health of the horse. 



The acute form is frequently induced by excessive exertion without 

 previous adequate training or condition, hence the number of cases occur- 

 ring among hunters and steeplechase horses pushed beyond their powers 

 with but little previous preparation. Fat young horses fresh from grass 

 or the hands of the dealer are particularly prone to this disorder, especially 

 when brought into town work and made to occupy badly- ventilated and 

 otherwise ill-conditioned stables. The same causes that produce catarrh or 

 common cold are liable to give rise to congestion of the pulmonary vessels, 

 and the disorder is a frequent sequel to, or complication of, inflammatory 

 attacks affecting other organs. As a mechanical congestion it is always 

 present more or less in obstructive diseases of the valves of the heart. 

 Here the blood, interrupted in its course through the last-named organ, is 

 made to accumulate in the vessels of the lungs. Passive congestion of 

 these organs mostly arises in the course of exhausting diseases, and par- 

 ticularly in that form of influenza termed " typhoid ". 



Symptoms. In acute cases the symptoms are very urgent. Rapid 

 but shallow breathing, "blowing" as it is called among horsemen, dilated 

 nostrils, bloodshot eyes, head depressed and commonly held in a corner the 

 least suitable for obtaining a supply of fresh air. The muscles quiver, the 

 body is hot with perspiration, and the ears and legs are icy cold. Redness 

 of the conjunctival membranes is not of that kind commonly seen in cases 

 of acute inflammation, but of a darker colour, as might be expected in an 

 animal whose blood is not receiving proper oxidation in the lungs. As a 

 rule, the horse so affected persistently stands, but there are exceptions, 

 some appearing to suffer acute pain and occasionally going down in a 

 vain effort to obtain ease, while others, and by far the majority, become 

 more or less dull and stupid. The heart-sounds are loud, and the pulse, 



