0 MR. youatt’s vkterinary lectures. 
^ • _ 
tissue, and the whole substance is gorged and infiltrated. These 
considerations sufficiently explain the frequency, and obstinacy, 
and fatal termination of thoracic inflammation in the horse, and 
prepare us for that which, leaving for awhile our anatomical de¬ 
tail and our necessarily imperfect physiological inquiries, next 
presents itself to notice, namely, the diseases of these portions of 
the respiratory apparatus. 
Catarrh in the Horse. 
I have already directed your attention to inflammation of the 
Schneiderian membrane, or that which lines the nasal cavity. 
Coryza is attended by a slight defluxion from the nose; now and 
then a yet slighter weeping, and some increased labour of breath¬ 
ing, on account of the uneasiness which the animal experiences from 
the passage of the air over the naturally sensitive, and now more 
than usually irritable surface; and from the air passage being dimi¬ 
nished by the thickening of the membrane; but when this is a 
simply local inflammation, attended by no loss of appetite or in¬ 
creased animal temperature, it may speedily pass over. 
Symptoms of Catarrh .—In many cases, however, the inflam¬ 
mation of a membrane naturally so sensitive, and rendered sa 
morbidly irritable by our absurd treatment, rapidly spreads, and 
involves the fauces, the lymphatic, and some of the salivary 
glands, the lymphatic glands of the lower jaw, and the throat, 
and the parotid gland, and also the membrane of the larynx. 
We have then increased discharge from the nose, greater redness 
of the pituitary membrane, more defluxion from the eyes, and 
loss of appetite from a degree of fever associating itself with the 
local aflection, or apparent loss of appetite from pain in swallow¬ 
ing, and if the animal feels this he will never eat. Cough now 
appears more or less frequent or painful, referable generally to the 
upper respiratory passages ; but no great degree of fever or ac¬ 
celeration of the pulse, or heaving of the flanks; there is, how¬ 
ever, more or less defluxion from the eyes. 
Causes of Catarrh .—Catarrh may arise from a thousand 
causes. Membranes subjected to so many sources of irritation 
soon become irritable. Exposure to cold or rain, change of sta¬ 
ble, change of weather, neglect of grooming, change of the 
slightest portion of clothing,—many circumstances apparently 
trifli nof, and which they who are unaccustomed to horses would 
think could not possibly produce injurious eflfect, are the causes 
of catarrh. When there is any thing about the animal that fa¬ 
vours this general febrile action or local determination, catarrh 
can scarcely be voided. In the spring of the year, and while 
moulting, almost every young horse has a cough; and in the 
