Part 85

The first symptom is a rise of temperature, and this may last two or even three days before other morbid phenomena are noticed. It may rise to 104° F. in the first day and later to 107°, 108° or 109°. The more acute the case and the hotter the weather the greater the rise. The highest records are obtained late in the day, the lowest in the morning. The temperature often rises for two to four days, and then suddenly drops with the occurrence of collapse and imminent death. While the thermometer is of the highest value in taking the temperature, yet the extraordinary hyperthermia is easily detected by grasping the root of the horn or ear, or by feeling the nose, feet, anus or lips of the vulva.

After 2 or 3 days the respirations become accelerated to 60 to 100 per minute, and the pulse to 90 to 100 or more. There is complete loss of appetite and rumination after the development of these symptoms, the mouth is hot and it may be dry, the muzzle dry, the head pendent, the eyes dull or semiclosed and congested (usually icteric), the bowels confined, to be relaxed again as the fever subsides. A disposition to stand or lie down in water has been frequently noted. Nervous symptoms are usually present. The extreme dulness, languor, and apathy, the drooping head and ears, the unsteadiness of the support the animal staggering or propping himself up by spreading all four limbs, and the tendency to assume and retain a recumbent position, are marked phenomena in our domesticated northern cattle. The paresis may absolutely incapacitate the animal from getting up. In our wilder range cattle it may show itself in active delirium and Lignieres notes the same of the Pampas cattle in Argentina. The animal lying dull and apathetic (triste), on being approached may raise his head, open his eyes and glare threateningly at the intruder. Sometimes when trembling violently, and swaying ready to fall, he will marshal all his remaining energy to plunge at a man on foot or mounted. Some have become blind and unconsciously walked against obstacles, others have been noticed to run in wide circles.

The milk secretion is suppressed, any little that can be drawn in the advanced stages having a thick, creamy appearance. Abortion is common in the pregnant cow.

The condition of the urine has, however, always drawn especial attention and the names red-water and hœmoglobinuria have accordingly been largely applied to the disease. When, in infected areas, the milder types of the disease have failed to show red-water (Jamaica), the identity of the affection with Texas fever has even been denied. Shortly after the rise of temperature, the urine becomes turbid, and this gradually encreases to a more or less deep red. It assumes its darkest hue when the destruction of red globules is most active and during convalescence it disappears. The suppression of urinary secretion may account in some cases for the absence of this symptom even at the crisis of the fever, yet, as a rule, it is present at such time, and, even though it may have escaped notice during life, the red-water is found in the bladder at the necropsy. It may be of all grades, from the merest tinge of redness to a reddish brown, coffee-grounds, or blackish aspect. The coloration is not due to red globules, but to the hæmoglobin which has escaped from the disintegrating globules, and been eliminated by the kidneys. It is always associated with albumen, and, in the advanced stages and during convalescence, when the elimination of hæmoglobin has ceased, that of albumen continues in small amount for weeks.

The thin, watery appearance of the blood when the disease has reached its height, is constant and even more characteristic than the red-water. A single drop drawn from the skin will show to the naked eye the pale, thin, transparent appearance, but examination under the microscope will confirm this. It remains, too, for a length of time, being recognizable for a month in cases of recovery. In connection with the watery blood, the mucosæ and the muzzle (if naturally white) assume a pallid aspect. This is best marked in the absence of icterus, yet even with the yellow discoloration, the absence of ramifying red vessels is very characteristic.

The bowels are at first constipated and the fæces passed in small, hard balls. Later they may assume a reddish brown or chocolate color, and a covering of mucus and fine blood clots. Diarrhœa supervenes in some cases. In passing the fæces, the everted mucosa usually shows a dark red color.

Course and Duration. Acute cases, above all if traveled or otherwise excited, may terminate in death in 24 to 48 hours. More commonly death will take place in 4 to 7 days. Some patients survive longer, but owing to the extraordinary loss of blood globules and the lesions of important solid tissues they are unable to rally, become steadily weaker and perish in from two weeks to three months. Such animals are pale and bloodless, weak on their limbs, careless of food, and encreasingly emaciated. The pulse is weak and irritable and the eyes sunken. The temperature becomes normal or nearly so, soon after the suspension of the hæmoglobinuria. In cases of recovery there remains for a month or more an unnatural pallor, with marked loss of condition and weakness which are only gradually overcome. Convalescent animals are liable to die of indigestion when overfed.

The mortality averages not less than 90 per cent. in susceptible mature cattle from a healthy district in the hot season. Later, from October onward, the tendency is to a milder type of disease and a greater ratio of recoveries.

Symptoms of the Mild Type. This is seen mainly in cattle indigenous to the Texas fever district, in sucking calves, and in mature cattle from healthy districts but attacked during the cool or winter season. It can be produced at will by placing a limited number of ticks (5 to 20) on the skin of susceptible cattle, especially in the cool season. Again, it occurs as a relapse in cattle that have survived an attack earlier in the season.

Though there are all gradations from the violent type, yet we may set down as mild all cases in which the temperature does not rise above 105° F., running frequently about 103° F. There is loss of appetite, dulness, languor, costiveness, scanty urine, albuminous but not hæmoglobinuric, pallor of the mucosæ, and marked loss of condition. Examination of the blood shows the presence of the parasite in the red globules but usually in the coccus or round form only, and the destruction and disappearance of the globules is much less marked so that, though the blood is anæmic and watery, it is not nearly so much so as in the violent and fatal cases. Without the examination of the blood it may be impossible to distinguish these cases from other febrile affections, yet occurring as they do in the infected district in a number of animals at once, in the cooler season, and showing albuminuria, and marked anæmic symptoms, they should lead to suspicion and a search for the boöphilus on the skin, and the oligocythemia and the protozoa in the blood.

Differential Diagnosis from Anthrax. As anthrax is the one disease with which Texas fever is most likely to be confounded, it may be profitable to collect in tabular form their differential features:

=Protozoan Cattle Fever.= =Anthrax.=

A disease of given districts, Prevails in rich, swampy wooded, swampy, uncultivated, impermeable soils: not and places where cattle from permanently implanted on open these districts are taken. well drained lands.

Always shows Boöphilus, minute or Has no essential connection with mature, on the skin of the the Boöphilus: latter usually patient. absent.

Extends in warm season, as the Practically never conveyed by the Boöphilus from an infected Boöphilus. district is introduced.

Can be carried by the Boöphilus apart from cattle.

Infection destroyed by winter Infection not destroyed by winter frost above 35° of N. latitude. frosts.

Attacks bovine animals only. Attacks mammals, generally, especially herbivora.

Lapse of 5 to 6 weeks after Outbreak may occur at once after introduction, for tick introduction of infection. development, precedes outbreak.

Confined mainly to summer season. Occurs at any season: most prevalent in summer.

Sucking calves nearly immune. Sucking calves susceptible.

Mucosæ become increasingly pale; Mucosæ dusky brownish red, not icteric in violent attacks. pallid, nor icteric.

Urine red or blackish in acute Urine exceptionally red: blood cases at height of the disease. globules, in some cases. Hæmoglobin. Albumen.

Blood becomes increasingly thin Blood becomes thick, tarry, and watery: Oligocythemia. incoagulable; not watery nor oligocythemic.

Blood reddens more or less in air: Blood reddens little, or not at then becomes darker. all on exposure.

Spleen greatly enlarged, purplish, Spleen greatly enlarged; pulp very often firm: pulp reddens dark does not redden in air. slightly in air.

Liver enlarged, congested, often Liver enlarged, congested, dark yellow, with fatty and necrotic red or violet. areas: remarkable yellow injection of radical bile ducts.

Bile abundant, thick, tarry. Bile fluid.