Part 23

Carried in manure, on Carried in manure, on harness, wagons, harness, wagons, clothes, etc. clothes, etc.

Incubation, 3–10 days Incubation, 1–2 days

Rigor may be late: Rigor early and well Rigor not always well after exudation has marked, before marked commenced exudation

Sets in slowly or with Sets in slowly, cough, Profound nervous acute congestion; dulness, impaired prostration like appetite and pulse appetite, pulse opium poisoning, vary with rapid, prostration appearing early and inflammation slight suddenly

Nasal discharge, watery Nasal discharge, yellow Nasal discharge, or rusty, later watery, may become muco-purulent yellow

Eye pink, dark red Eye yellow, rarely Eyelids bloodshot (pink swollen or watery eye), violet, madder hue, swollen, watery, closed

Temperature rises with Temperature rises early Temperature rises early inflammation and extremely, before and extremely, in exudation, 104°–107° some hours, 104°–107°

Swelling of limbs rare Limbs swell rarely Limbs often swell greatly

Rheumatoid arthritis Rheumatoid arthritis may follow may set in; often in advanced stage

Crepitation more Crepitation less Crepitation may escape constant around the constant around the recognition exudation exudation

Exudation Exudate affects lower Exudate less granular (Hepatization) in or anterior border of than in pneumonia; lung, lower, lung; often in small forms in or posterior, anterior, isolated areas or gravitates to lower or central, usually around bronchia; less part of lung. undivided area blood engorgement Congestion passive than in fibrinous pneumonia

If pleurisy effusion Pleural effusion Pleural effusion may be copious infrequent, or frequent and abundant limited, though pleurisy is common

Abscess not infrequent Abscess rare Abscess not infrequent

Pulmonary gangrene Pulmonary gangrene and Infarctions, sequestra, infrequent sequestra frequent and cavities not uncommon

Pericarditis infrequent Pericarditis frequent Pericarditis frequent

Blood, decrease of red Less altered than in Blood at first clots globules; encrease of either of the other firmly, later white, hæmatoblasts, forms. Shows becomes, thick, fibrine formers and cocco-bacilli in the black, sizy, soda salts earlier stages: hæmatosis tardy. streptococci later Reaction acid.

Coagulation firm, buffy Coagulum loose, buffy coat coat slight

Hepatic congestion, not Hepatic congestion Hepatic congestion hepatitis excessive, hepatitis, excessive, necrotic changes hæmorrhagic; fatty degeneration

Prognosis. Mortality. As usually met with and under favorable conditions, equine influenza is a mild disease. In 1872 when the disease, sweeping the continent and hardly sparing an equine animal, might be assumed to have reached its maximum, the actual deaths varied from 2 per cent. in country districts to 7 per cent. in large cities. The same holds for Europe where Friedberger and Fröhner gives 4 to 5 per cent. Früs (Denmark) 1 per cent., Aureggio (Italy) 3 per cent., Siedamgrotzky 10 per cent. Much depends on conditions: In horses infected in transit on a long railroad journey it may be 100 per cent. and in fat dealer’s horses, out of condition for active work it usually reaches a high figure. If the patients are kept at work the complications and mortality run very high. The same applies to debilitated animals kept in close, foul, ill-aired stables, or reduced by exhausting or long standing diseases. The very young and the senile suffer more than animals in middle life and vigorous condition. Finally the parts invaded have a controlling effect. The milder cases affecting the upper air passages only, nearly all recover, in those showing abdominal lesions the indications are still favorable; while with double pulmonary and pleural lesions the patient is too often in a hopeless condition. Brain lesions are almost equally redoubtable.

The actual money losses, in an epizoötic of influenza, are more in the way of the loss of work and the complete stagnation of trade in all departments, than in the number of deaths. Yet even in this sense it may prove more ruinous than would a disease having a less universal sway, though far more fatal to the animals attacked.

Treatment. A disease like this, which tends to spontaneous and perfect recovery, needs mainly dietetic and hygienic care in the vast majority of cases. Rest is a prime consideration in a pure genial atmosphere. In the summer season, in the absence of rainstorms, an open air life, at pasture is the best. Shelter must be had in case of storms, and in the cold season a clean, sweet, roomy well-aired loose box, with a sunny exposure, is important. Clothing, bandages, blankets and even hoods may be required if there is any tendency to chill. Food should be laxative, cooling and of easy digestion. Bran mashes, scalded oats or barley, ensilage, roots, potatoes, apples, fresh grass or scalded hay may be suggested. Milk has been strongly advocated, from twelve to fifteen quarts a day, and linseed tea as being especially adapted to the irritable stomach and bowels. Food should be given often, in small quantities so as not to destroy the appetite.

Costiveness is best met by injections of water, blood warm, or if there is much hyperthermia, of cold water. This latter stimulates the peristalsis more actively and at the same time lowers the temperature. By unloading the large intestines it removes irritants, without danger of encrease of congestion or diarrhœa.

If anything more is wanted for these mild cases, small doses of stimulating diuretics or diaphoretics may be given. Sweet spirits of nitre ½ oz. or liquor of acetate of ammonia 2 oz. may be given twice a day, the latter in the drinking water or gruel. In the absence of these saltpeter ½ oz, or potassium acetate ½ oz. may be given.

In the more severe cases more active treatment is resorted to, but in all cases one should avoid measures that tend to greatly depress the vital powers and especially the circulation. Heroic treatment has been all but universally condemned and yet Trasbot claims to have had excellent results from a moderate venesection (2–5 qts.) in strong, muscular, well conditioned animals. The blood became more fibrinous, the general symptoms improved and complications were far less marked. During twenty years, in a large number of cases, it had constantly the same results, restoring appetite, opening the closed eye, imparting new life, lowering temperature, and checking congestions. The results were best in all cases when it was employed early, but they were almost equally good when later congestions set in, or when the ordinary inflammatory localizations were advancing, and he found the measure hurtful only when, in the advanced stages, the animal was worn out, and destitute of all power of recuperation.

Antipyretics have been lauded and decried, and it is doubtless best to use them with due discrimination and caution. Acetanilid, the agent in most common use, is a powerful cardiac depressant, and in this disease the heart is often already dangerously weak. Yet in cases with very high temperature, seriously threatening life, acetanilid in doses of 2 drams, repeated every second or third hour until the temperature falls, and thereafter twice or thrice daily, for a day or two, may save the patient. Similarly, where there are indications of violent headache (drooping head, eyelids and ears, congested and watery conjunctiva, stupor or irresponsiveness) a dose or two of acetanilid with the same amount of sodium bromide will often give material relief. The general suffering and disorder attendant on the cephalalgia, if allowed to continue, prove a direct bar to improvement, and endanger complications that might otherwise be escaped. On the other hand, there is constant danger from too large doses, or a too long continued use of acetanilid in influenza. Phenacetin may be substituted in 2 dram doses, the action being somewhat more prompt and transient. As less dangerous than the coal tar antipyretics, we may fall back on such agents as sodium salicylate, ½ to 1 oz., or sulphate of quinia, 20 grs.

Elimination of toxins and waste products is to be secured and this is more safely conducted by the kidneys or skin than by the irritable alimentary canal. Plenty of pure cold water is one of the best and simplest resorts. Aside from this, where there is much hyperthermia, bicarbonate of potash or soda will serve the various purposes of an antidote to the acid blood, an eliminant and an antithermic. Under the same circumstances saltpeter may be resorted to in ½ oz. doses twice daily. When, however, the heart is weak it is better to employ ammoniacal or etherial diuretics:—spirits of nitrous ether, 1 oz. or liquor of acetate of ammonia, 2 to 4 ozs. By combining these with extract of belladonna and camphor a fairly standard prescription may be prepared.

Inhalations of warm water vapor, rising from hot water or a hot mash in a bucket, over one end of which a bottomless bag is drawn, while the other end receives the nose of the horse, will greatly relieve the irritation and the cough. It can be made even more soothing by introducing a little alcohol, eucalyptol, menthol, camphor, poppy-heads, or other anodyne. Or the water vapor may be set free in a close stall from a boiling tea-kettle or a steam pipe, and an admixture of sulphurous acid made by burning a few pinches of sulphur, more or less according to the size and closeness of the stall. If the stall is tight enough a steam bath may be given with much profit in the early stages.

Counter irritants applied to the throat, or, if need be, to the breast and sides of the chest will often give material relief, acting as derivatives and probably also by modifying the globulins in the exudate and thus influencing the course of the disease. In case of sore throat of a very high type it may be best to apply a compress or poultice, or even a piece of sheepskin for a day or two, until, by antithermics, cooling diuretics and soothing inhalations, the severity of the inflammation has abated. The common mustard pulp made with tepid water, rubbed in, and covered by paper, may be applied for an hour; or the soap liniment (soap 6 ozs., camphor 3 ozs., and proof spirit, liquor ammonia and linseed oil aa 1 pint) may be rubbed on repeatedly; or a blister of cantharides may be used.