THICK WIND. 495 
cells, which is retained there, as the urine is in the bladder, from the 
valvular nature of the openings, and cannot be entirely expelled, nor in 
the slightest degree, without calling into play all the muscles of the chest. 
The presence of unchanged air is a constant source of irritation to the 
lungs, and although sufficient may be expired easily enough to carry on 
their functions while the body is at rest, yet instinctively there is a desire 
to get rid of the surplus, and hence the two acts of respiration. Im- 
mediately after this second act the muscles relax, and the flank falls in, 
and this it is which catches the eye in so remarkable a manner. On 
examination after death, the lungs are found to remain enlarged, and do 
not collapse as in the healthy condition. They are distended with air ; 
and this is especially the case when the emphysema is of the kind called 
interlobular, in which the air has escaped into the cellular membrane. In 
the most common kind, however, the cells are broken down, several being 
united together, while the enlargement pressing upon the tube which has 
opened into them diminishes its capacity, and prevents the ready escape 
of air. This is the vesicular emphysema of pathologists. The former is 
generally suddenly produced by a severe gallop after a full meal, while 
the latter is a slow growth and often occurs at grass, as a consequence of 
neglected chronic cough, the constant muscular efforts appearing gradually 
to dilate the cells. 
The treatment can only be palliative, as there is no recognised cure for 
the disease, though M. Hew, of Chaumont, has lately published a report 
of ten cases in which treatment by arsenic given with green food or 
straw, and in some cases bleeding, was perfectly successful. The arsenic 
was given to the extent of fifteen grains daily, and at the end of a fort- 
night the symptoms of broken wind were completely removed ; but as 
the horses were not subsequently watched it is impossible to say whether 
the cure was permanent. It is known, however, that one of them relapsed 
after three months, but speedily yielded to a repetition of the treatment. 
It may certainly be worth while to try the experiment of the effect of 
arsenic where a broken-winded horse is valuable in other respects. The 
medicine is not expensive, and the length of time necessary for the . 
treatment is not very great. Broken-winded horses should be carefully 
dieted, and even then confined to slow work. ‘The food should be in 
small compass, consisting chiefly of wheat-straw chaff, with a proper 
quantity of oats, and beans may be added if the animal is not very 
young. ‘The water should never be given within an hour of going out 
of the stable, but it is better to leave a constant supply, when too much 
will never be taken. Carrots are peculiarly suited to this disease, and a 
diet of bran mixed with carrots, sliced, has sometimes been known to 
relieve a broken-winded horse most materially. 
THICK WIND. 
THICK WIND is the horseman’s term for any defective respiration, unac- 
companied by a noise, or by the signs of emphysema just alluded to. It 
usually follows pneumonia, but it may arise from chronic bronchitis, occa- 
sioning a thickening of the mucous membrane lining the bronchial tubes, 
and thus lessening their diameter, or it may accompany phthisis when the 
deposit of tubercles is extensive. No treatment will be of any service 
except such as will aid the play of the lungs mechanically, by avoiding 
overloading the stomach, as mentioned in the last section. 
