Sequel of acute: or subacute from the first. Due to œstrus, in cattle
to summer catarrh, tubercle or actinomycosis. Lymphatic horses
predisposed; attends chronic indigestion; in swine tonsilitis.
Symptoms: chronic cough, easily roused, wheezy or mucous; nasal
discharge; low condition; lack of spirit. Lesions: congestion;
softenings; erosions; cicatrices; tonsilitis; abscesses; specific
deposits. Treatment: hygienic; antiparasitic; astringent; antiseptic;
derivative; counter-irritant; tonic inhalations and electuaries.
Bitters. Iron.
_Causes and Nature._ Chronic pharyngitis in animals may be a simple
continuation of the acute, in a milder form, or it may assume a subacute
or chronic type from the first and never rise to the intensity that
would characterize the acute. It may be a simple catarrhal affection or
it may become more or less follicular or glandular. Again in horses it
is not infrequently a result of the hibernation form of the œstrus
(bots) attached to the delicate pharyngeal mucosa, and in cattle from
the extension of the chronic summer catarrh, or from the local
development of tubercle or actinomycosis in the walls of the pharynx or
in the adjacent lymph glands. Horses of a soft, lymphatic constitution,
with a heavy coat, confined in close warm stalls, and which perspire
abundantly are especially liable to the affection. It may also be an
accompaniment and result of chronic gastric indigestion. In swine the
affection is commonly associated with tonsilitis.
_Symptoms._ In many cases the main symptom is a chronic cough which is
aroused by any cause of irritation, feed, especially dry or fibrous
fodder, cold drinking water, sudden passing from the hot stable to the
cold outer air, reining in, pressure on the throat, or sudden active
exertion. If the cartilages are calcified it may be impossible to rouse
the cough by pressure. The cough is often dry and wheezy, rather than
soft and gurgling as in the second stage of acute pharyngitis, and is
repeated several times paroxysmally. In the intervals there is more or
less stertor or wheezing, or a distinct rattle especially when the neck
is curved by drawing the nose inward. Deglutition may be interfered with
but this shows most with the first swallow, which in the case of liquids
may be returned through the nose, whereas those that follow go down
without difficulty. A lateral swelling of the parts above the larynx or
a bulging of the parotids is not uncommon. Discharge from the nose of a
mucopurulent character is usually present, but often so scanty as to be
overlooked. There is usually loss of flesh and lack of vigor even if the
subject is well fed.
_Lesions._ In the simple catarrhal form the mucous membrane of the
lateral pharyngeal walls, the posterior pillars of the palate and the
back of the soft palate, is red, congested, with arborescent vessels,
thickening, and puckering into rugæ. The epithelium has lost its
translucency, become opaque and granular, and its desquamation in spots
and patches may leave erosions, ulcers more or less deep, and white
drawn cicatrices. When the follicles and mucous crypts are involved
(follicular) they stand out like millet seed, peas or beans, and may
show ulceration or minute abscess. In pigs especially, tonsilitis is
liable to be present, and the tonsillar follicles are filled and
distended with tenacious mucous, a caseous granular _debris_, or even a
cretaceous material. In the vicinity of the tonsils, minute abscesses
may exist in or beneath the mucosa.
Ulceration may be the result of tubercle, glanders, actinomycosis,
aspergillus, sarcoma, or some local infection, and attendant symptoms of
one or other of these diseases will guide the diagnosis. Thus in
tubercle there will be the implication of the adjacent lymph glands and
usually of distant ones; in glanders the deposits in the nose,
submaxillary lymph glands and lungs will enable one to diagnosticate; in
actinomycosis the hardness of the neoplasm and the presence of the
yellowish tufts which present under the microscope the concentrically
arranged club-shaped elements, will show its nature; and in sarcoma or
carcinoma the structure of the new tissue will decide its character. The
pharyngeal muscles are the seat of granular or fatty degeneration or of
fibroid change. Friedenreich speaks of a fold from the vault of the
pharynx which had nearly closed the passage and had killed the horse by
inability to swallow.
_Treatment._ Chronic pharyngitis is usually a very obstinate affection
and demands careful hygienic as well as medicinal treatment. Hot, foul
stables, unduly thick coats, unwholesome food, irregular feeding,
excessive meals at long intervals, overwork, undue exposure to cold and
wet, lack of sunshine or of grooming are to be corrected. Next, the
removal of mechanical irritants such as pharyngeal bots, actinomycosis
growths, etc., will be in order. Then the use of astringents and
antiseptics internally and of derivatives externally will be demanded.
An occasional embrocation of mustard, or the application of ammonia and
oil, will often serve a good purpose, and in obstinate cases the hot
iron in points will sometimes prove effective.
Internally the inhalation of the fumes of tar, carbolic acid, creolin,
oil of turpentine, or of burning sulphur kept up continually or
frequently repeated. Giving all drink in the form of tar water will
often have a good effect. Electuaries made with boric acid, salicylate
of soda, ammonium chloride or iodide, borax, with honey, molasses,
liquorice, Iceland moss, or gum arabic will often prove beneficial.
Agents that stimulate the mucosa may follow, such as balsams of Peru or
Tolu, copaiba, cubebs, pilocarpin, wild cherry bark, or these may be
combined with the former. Finally a course of tonics are usually of the
first importance; iron sulphate, copper sulphate, arsenious acid,
arsenite of strychnia may furnish examples.