Text book of veterinary medicine, Volume 4 (of 5)

by James Law

In other cases, and often quite early in the disease, the swellings may suddenly subside and disappear, with it may be, a recovery, or, in other cases, with an exudation into the lungs or chest, the digestive organs or abdomen. In case the lungs are attacked, there is hurried oppressed breathing merging into dyspnœa or asphyxia. In case the bowels suffer there are colicy pains more or less acute, with much constitutional disturbance, marked prostration and serous or bloody diarrhœa. These mostly prove speedily fatal. Less redoubtable are those cases in which the swellings alternately subside or moderate, and reappear or increase, without implication of the internal organs. The absence of internal lesions and the moderation and intermissions, of the external ones, give good hope of the preservation of the vitality of the tissues and of recovery.

Course and Duration. These vary much with the severity of the case. In subacute and tardy cases with few petechiæ and restricted swelling in the limbs, the symptoms become remittent and recovery finally takes place after one or two months. In other cases the morbid phenomena which developed rapidly may subside as quickly and recovery occurs in a few days. In the more typical case the visible lesions may encrease or remain stationary for one, two or three weeks and then terminate in death or recovery. In the most violent types death may occur within forty-eight hours. The average duration of the affection is found to be about 16 days.

Differential Diagnosis. In typical cases of petechial fever, diagnosis is easy. The supervention on a protracted or debilitating disease of the respiratory passages of an access of hyperthermia, and marked prostration, with the appearance on the nasal or other mucosa of petechiæ and swellings of a dark red color throughout, and of cutaneous swellings in the form of nodular elevations and more extended salient patches, having a tendency to ooze blood or serum, to crack and fissure is virtually pathognomonic.

Acute glanders may resemble it but lacks the extended sloughs of petechial fever, and the nasal ulcers that form in glanders are on a yellowish base and periphery, whereas the purpura ulcer is on an uniformly dark red base, and without the elevated margin seen in glanders. In cases of doubt the mallein test is not available as the purpuric patient is already fevered, or liable to be so at any moment, and any wound in such a subject will give rise to extensive swelling.

In glanders the nodular submaxillary enlargement is almost pathognomonic and still more so if the facial lymphatic vessels are thickened (corded) and both symptoms fail in purpura. In cutaneous glanders with swollen joints or limbs the attendant pain is much more severe, and the farcy buds, forming on the thickened and indurated lymph vessels, bursting and discharging an albuminoid fluid like oil have no counterpart in petechial fever. In cases of doubt the search for the glander bacillus, and above all the inoculation of a male Guinea pig in the flank and the discovery of the bacillus mallei in the resulting exudate and diseased testicle will decide.

From anthrax and emphysematous anthrax petechial fever is distinguished by the absence of the large bacilli of these respective diseases from the exudate. It is not communicable, like anthrax, to the sheep, Guinea pig and rabbit, and does not crackle on manipulation, like emphysematous anthrax. The swellings are much more generally diffused than in anthrax and the hyperthermia much less.

Urticaria furnishes a skin eruption which may be indistinguishable from the earlier skin lesions of petechial fever, but these lesions are not associated with the petechiæ in the nasal and other mucosæ, and the swellings do not advance to great sanguineous engorgements, cracks, fissures, necrosis, and deep and extensive sores as in purpura. Urticaria is, moreover, usually traceable to some digestive disturbance and fault in feeding.

Malignant œdema is usually confined to the seat of the inoculation wound and an extension around that, the exudate is very watery and may be mixed with fetid gas bubbles, so as to crepitate slightly, and it contains an abundance of its specific, round ended bacillus, often in chain form. The carcass putrefies with great rapidity.

Horse pox affecting the pastern and limb with attendant swelling is distinguished by the absence of petechiæ on the mucosæ, and by the formation on the affected part of little pea-like papules, which early exude an abundant liquid, the concretion of which on the hairs forms a remarkable yellowish encrustation, embedded in the angry red sores beneath.

Mortality. Prognosis. The mortality has generally averaged about 50 per cent. Much, however, depends on the violence of the attack, and the reduced and worn out condition of the patient. The most hopeful cases are those in which the temperature remains near the normal, the strength and appetite are well sustained, the swellings are comparatively slight, and there is no indication of any internal complication. The unpromising symptoms are: persistent high temperature; complete anorexia; great dulness and prostration; excessive swellings not only cutaneous but in the nose and throat as well; a marked oozing from the swellings with a tendency to form cracks, fissures and sloughs; the serious obstruction of breathing and prevention of hæmatosis by blocking of the nose, pharynx or larynx by sanguineous and serous exudate; the appearance of oppressed breathing and other indications of exudate with the lungs and chest, or of colics, diarrhœa, and other suggestions of effusion on the bowels or in the abdomen. Extreme fetor of the expired air and of the fæces is a bad symptom, though not always a fatal one. Sudden retrocession of the cutaneous swellings, may be the precursor of internal exudations and death, yet in the absence of marked acceleration of the pulse, and of the objective symptoms of disease of the chest or abdomen, it is rather to be taken as a herald of recovery.