"Postmortem.

I. Blood removed from the heart or great vessels.-Horse No. 38 inoculated with 1 c. c. of blood taken 9 hours postmortem, from which the hematozoon was absent, but very numerous antemortem. Latent period 9 days. Horse No. 41 inoculated with 1 c. c. of blood taken 94 hours postmortem from case No. 40, from which the hematozoon was absent, but very numerous antemortem. Latent period 7 days. Horse No. 40 inoculated with 0.6 c. c. of blood taken 1 hours postmortem from case No. 34, from which the hematozoon was absent, but very numerous antemortem. Latent period 6 days. Horse No. 31 inoculated with 0.3 c. c. of blood taken 8 hours postmortem from case No. 33, from which the hematozoon was absent, but swarming antemortem. Latent period 9 days.

II. Blood serum removed from the large vessels.-Horse No. 50 inoculated with 2 c. c. of blood serum taken 45 minutes postmortem from case No. 38, from which the hematozoon was absent, but swarming antemortem. Latent period 9 days.

“Antemortem.

66 INOCULATION OF OTHER ANIMALS THAN HORSES.

I. Blood taken during a paroxysm from horses— (a) By subcutaneous injection. Bull: 1.7 c. c. containing very numerous hematozoa. Latent period 7 days. Sheep: 0.8 c. c. containing a few hematozoa, and with 1 c. c. containing a few hematozoa 14 days later, no organism found in the blood, but they were found on the fifty-ninth day in the fluid of the tunica vaginalis testis. Goat: 0.5 c. c. containing swarms of hematozoa. Latent period was 7

"Postmortem.

days. Rabbits: 0.3 c. c. containing very numerous hematozoa, latent period 5 days; 0.3 c. c. containing very numerous hematozoa, latent period 9 days. Guinea pigs: 1 c. c. containing very numerous hematozoa, latent period 12 days. Guinea pigs: 1 c. c. containing very numerous hematozoa, latent period 9 days. Guinea pigs: 0.5 c. c. containing very numerous hematozoa. This was a pregnant doe, and the latent period was 7 days, showing that pregnancy predisposes. Rats (Mus decumanus): 0.2 c. c. containing very numerous hematozoa. Latent period, 1 day. Rats (Mus decumanus): 0.1 c. c. containing a few hematozoa. Latent period, 2 days. Rats (Mus decumanus): 0.1 c. c. containing a few hematozoa. Latent period 2 days. Rats (Nesokia providens): 0.2 c. c. containing numerous hematozoa. Latent period, 2 days. Rats (Nesokia providens): 0.2 c. C. containing numerous hematozoa. Latent period, 5 days. Rats (Nesokia providens): 0.2 c. c. containing numerous hematozoa. Latent period, 5 days.

I. Blood and other fluids removed from the body(a) By subcutaneous inoculation. Goat No. 3 inoculated with 1 c. c. blood taken 5 hours postmortem, from which the hematozoon was absent, but swarming antemortem. Latent period, 6 days. Guinea pig inoculated with 0.4 c. c. cerebrospinal fluid 2 hours postmortem, hematozoa absent, but very numerous in the blood antemortem. Latent period, 11 days. Guinea pig inoculated with 1 c. c. pericardial fluid 13 hours postmortem, hematozoa absent, but swarming in the blood antemortem. Latent period, 10 days. Guinea pig inoculated with 1 c. c. pericardial fluid 13 hours postmortem, hematozoa absent, but swarming in the blood antemortem. Latent period, 10 days." (Lingard, 1893, pp. 55-61.)

STAGES AND DURATION.

The duration of surra varies with the species of animals attacked, their age and general condition, but sex has no influence. According to Griffith Evans (1881, p. 4), the records of the Fourth Punjab Cavalry show an average duration of 43 days after admission on the sick list. Burke (1888a, p. 9; 1891, p. 268) gives the average (taken from Evans) as probably not less than 2 months. According to Burke (1897, p. 192), naturally weak animals succumb more quickly than strong ones; in some cases the course is very rapid, and may be (1891, p. 268; 1892, p. 192) less than 1 to 2 weeks. Nariman & Vaz (1893, p. 403) describe the animals as dying by inches. The Veterinary Journal, London (1896, p. 179), gives the duration as proportionate to the animal's age, constitution, and condition; young horses may pass through seven or nine paroxysms, while old, worn-out animals may succumb quickly. Pease (1897, p. 560) states that nearly all cases take a month or more to kill, and Hayes (1898, p. 481) quotes Gunn as authority for 52 days as the average duration.

In discussing the subject of stages and duration, Lingard (1893, p. 73) says:

"Stages.-The fever of surra, as before mentioned, varies to such an extent in different cases that it is impossible to group any number of them under any one system of description as regards the stages of the disease. The insidious nature of the onset in the naturally contracted disease, devoid of symptoms during a considerable period, renders it impossible to recognize it until such time as the organism appears in the blood. Consequently little is known concerning the latent period and stage of invasion, and in such cases, when untreated, the fever is of a continued type, followed by one or more intermissions at long but irregular intervals.

"In this disease, when artificially produced, the majority follow the type before mentioned, but a number present a peculiar series of symptoms, reminding one of relapsing fever in man. But here again certain variations are observed. Such cases as Nos. 20, 38, 50, 54, however, lend themselves to description, which will be made clear on reference to the charts, and may be described as presenting well-marked stages, viz:

"I. The period of incubation, or latent period.

"II. The primary paroxysm.

"III. The intermission.

"IV. The relapse.

"V. Death.

"The paroxysms, as in relapsing fever in man, are again subdivisible into the accession, the pyrexial stage, and the crisis. But in all cases of surra we find periods during which the hematozoon is present, and others during which it is absent. The only system, therefore, under which all cases can be grouped is that having for its basis the presence and absence of the organism; the former we term the paroxysm and the latter the period of intermission."

THE COAT.

The coat of affected animals is described as staring. (Griffith Evans, 1881, p. 2.)

PERSPIRATION.

This symptom is entirely absent during the whole course of the disease, until just before death, when, as a rule, profuse sweating occurs. (Lingard, 1893, p. 68.)

ERUPTION, URTICARIA, EDEMA.

Referring to eruption and edema, Lingard (1893, p. 64) says.

"Eruption. In the majority of cases, no eruption of any kind occurs during the whole duration of the disease. Steel, however, noted in mules an eruption of spots on the skin of the muzzle, resembling in its essential nature those he had observed on the mouth and nostrils. In the course of this investigation we have observed a number of cases of urticaria, appearing somewhat suddenly and, as a rule, disappearing after a few hours. The eruption has been either general or localized in character, and could be conveniently placed under several of the different classifications, viz: The affection which passes away in a few hours (Urticaria ephemera), or within a few days (U. evanida), or the form which is either preceded or accompanied by fever (U. febrilis), and lastly the (U. nodosa seu tuberosa), which is characterized by the appearance of nodosities of some size.

"If we further examine as to the dates on which the eruption occurred in the different cases, we find that in the naturally contracted ones (horses Nos. 65 and 73) it occurred on the first day of the disease, and was of the form known as Urticaria evanida; in horse No. 71 it appeared on the sixteenth day, and was an Urticaria ephemera; that in horse No. 3, on the eighteenth day was an U. ephemera also; and in horse No. 72, on the twenty-second day, U. evanida; in horse No. 20, which acquired the disease by gastric indigestion, it appeared on the ninth day of the disease, and was an U. ephemera; in the horses Nos. 22 and 6, it appeared in the former on the eleventh and in the latter on the twelfth day of the disease, both U. ephemera, And in the animals inoculated with the blood of the horses through the goat: In No. 41 the eruption appeared in 18 hours after inoculation (U. eranida), in No. 40 the eruption appeared in 68 hours after inoculation (U. evanida), in No. 30 the eruption appeared in 48 hours after the appearance of the hematozoon in the blood ( U. ephemera), in No. 50 the eruption appeared in 48 hours after the appearance of the hematozoon in the blood (U. ephemera)." (Lingard, 1893, p. 66.)

Consequently it will be seen that the eruption of urticaria may take place at any time from 18 hours after inoculation until the twentysecond day after the appearance of the hematozoon in the blood.

"Swelling and edema at the seat of inoculation in experimental cases.—When an animal has been subcutaneously inoculated with the soiled blood or other fluids containing the 'materies morbi' of 'surra,' considerable swelling, as a general rule, follows at the seat of such injection. If we analyze this symptom we find that on the day following the operation a small raised, somewhat circular tumor appears, about 1 inch in diameter, while in some cases, especially when the blood used was obtained some hours postmortem, the measurements greatly exceed this, as in cases 27 and 41. On the third day the swelling has increased in dimensions, and probably measures from 14 to 2 inches in diameter; it now appears tense, and is tender on manipulation. By the fourth day a still further augmentation in size, etc., has occurred, and from this date until the appearance of the hematozoon in the blood of the general circulation, the swelling, tension, and tenderness of the part may go on steadily increasing, or, as sometimes happens, it remains stationary. At this time it will be found that if the tumor be firmly grasped by the hand, one can

readily lift it up from the subcutaneous structure, proving that it only involves the skin. A point of great interest and a symptom of the greatest clinical value occurs at the time of the organism leaving the seat of the swelling-for the hematozoon has been proved, as in horse No. 8, to be present in the fluid of the tumor 3 days after inoculation, and 2 days before being discovered in the blood of the general circulation; and, in the case of horse No. 54, 24 hours before its first appearance in the bloodin that the raised tumor, which was previously tense and so tender that the animal flinched whenever touched, now suddenly becomes soft and flaccid, and manipulation of the parts can be carried on with little or no notice being taken by the inoculated animal.

"It will, therefore, be recognized that from the time of inoculation until the organism leaves the tumor for the general circulation, or, in other words, during the latent period of inoculation, this disease is purely a localized affection, and can therefore be treated either by excision or by the injection of antiseptics at the seat of inoculation.

"In 1 case only out of 22, which contracted the disease by experimental means, was the swelling absent from the seat of inoculation, but in this from first to last, during a period of 9 days, no swelling or thickening of the integument could be felt. The shortest time noted in horses during which the swelling attained its maximum, and commenced to decrease in size was 96 hours, and the longest 12 days, the average length of 21 cases being 6.7 days. Within a very few days after the appearance of the hematozoon in the blood, the tumor has usually decreased considerably in size, and after a fortnight only a slight thickening of the skin can be noticed on careful examination of the part." (Lingard, 1893, pp. 66–67.)

According to the Veterinary Journal, London (1896, p. 177), with the rise in temperature there is usually an attack of local or general urticaria. There is generally some edema of the limbs, about the fetlocks and hocks, and beneath the belly, chest, and sheath.

In a large proportion of the cases the legs are swollen, and when pressed with the fingers they pit. Sooner or later a similar swelling is found between the fore legs of mares or at the sheath of horses, and the animal is dropsical (Griffith Evans, 1881, p. 3); (p. 4) the progress is variable, often marked by an increase of dropsical swelling which, however, sometimes subsides, again returning worse than before. Evans has seen some cases, in the last stage, in which there was no swelling, although it had been there before.

Nariman & Vaz (1893, p. 404) refer to an edema of an evanescent nature on the hind limbs, beginning at the fetlock and extending upward; edema of the sheath and testicles extending slightly to the lower part of the abdomen; later it becomes more prominent on the hind limbs and is often seen on the fore limbs, while the edema of the abdomen extends to the chest and breast.

Dropsy is frequent (Steel, 1886a, p. 169).

SWELLING OF THE SUBMAXILLARY GLANDS.

The submaxillary glands sometimes become enlarged. Griffith Evans (1881, p. 3) says that in a small proportion of the cases the submaxillary glands are enlarged and tender; in a few cases (Griffith

Evans, 1881, p. 4) the swelling of the submaxillary glands develops into an abscess, with a gluey mucous discharge from the nose. No other swellings are noticed and no ulceration of the nose nor tubercle of the lungs.

EMACIATION.

According to Griffith Evans (1881, p. 4), the most constant invariable symptom in the progress of the disease is the wasting away of the flesh; and this appears the more remarkable, considering how much the patient eats and apparently with good appetite. This wasting, or withering away, goes on more rapidly in some cases than in others. Several authors refer to the patients as consisting only of skin and bones and as presenting a most pitiful appearance.

Lingard (1893, p. 80) says that the body is usually much emaciated, the word "surra" implying "rot" or "dry rot;" and the disease is characterized by a progressive loss of flesh, or withering of the tissues. In some cases, however, when the animal is carried off rapidly, owing to the severity of the fever or from other causes, it may be in fairly good condition.

EYES.

Lachrymation.-This at first is slight, but in some animals rapidly increases in amount until it becomes profuse. At a varying period in the disease there appears at the inner canthus a semigelatinous secretion, which may become mucopurulent in character, and during the presence of the hematozoon in large numbers in the blood, slight hemorrhages take place from the conjunctival membranes, and the secretion becomes blood-stained. At these times it always contains

the hematozoon in varying numbers. (Lingard, 1893, p. 72.)

Griffith Evans (1881, p. 3) remarks that the eyes are "weeping," while the Veterinary Journal, London (1896, p. 177), states that the eyelids are swollen, and perhaps conjunctivitis may be present. Lachrymation may be profuse toward the end of the disease.

Petechiae. If the eyelids are inverted (Griffith Evans, 1881, p. 3) the conjunctival membrane is seen to be of a decidedly yellow color, often a dirty yellow, with claret-colored spots (petechia) on the eyelids, or, as is most common, on the membrana nictitans at the inner corner of the eye. According to Steel (1886a, p. 169), a characteristic feature of the disease, and one which seems to be in direct and close relations with the activity of the parasites in the blood, is the occurrence of "crops" of petechiæ, especially detectable on the conjunctivæ; they seem to occur when the parasites have attained their maximum activity and frequency, and when the temperature begins to fall.

This is not the only disease in which petechiae or more extensive extravasations occur, for these are usually present in anthrax, so-called