Symptoms. The symptoms are still less marked than in the pig, and in ordinary cases of infection always escape observation. Stiles, however, gives the following account of a case experimentally infected:—
Fig. 41.—Several portions of an adult beef-measle tapeworm (Tænia saginata) from man, showing the head on the anterior end and the gradual increase in size of the segments, natural size. (Stiles, Annual Report U.S.A. Bureau of Agriculture, 1901.)
“Symptoms. Four days after feeding segments of T. saginata to a healthy three-months-old calf, the patient showed a higher temperature (the normal temperature was 39·2° C.). The calf ate but little on that day, showed an accelerated pulse, swollen belly, staring coat, and upon pressure on the sides showed signs of pain. The next day the animal was more lively, ate a little, and for nine days later did not show any special symptoms except pain on pressure of the abdominal walls, and a slight fever. Nine days after the infection the temperature was 40·7° C., pulse 86, respiration 22; the calf laid down most of the time, lost its appetite almost entirely, and groaned considerably. When driven it showed a stiff gait and evident pain in the side. The fever increased gradually, and with it the feebleness and low-spiritedness of the calf, which now retained a recumbent position most of the time, being scarcely able to rise without aid, and eating only mash with ground corn. Diarrhœa commenced, the temperature fell gradually, and on the twenty-third day the animal died. The temperature had fallen to 38·2° C. During the last few days the calf was unable to rise; in fact, it could scarcely raise its head to lick the mash placed before it. Pulse was reduced by ten beats. On the last day the heart-beats were very much slower, yet firm, and could be plainly felt. Several days before death the breathing was laboured, and on the last day there was extreme dyspnœa.”
Fig. 42.—Apex, dorsal, and lateral views of the head of beef-measle tapeworm (Tænia saginata), showing a depression in the centre of the apex. × 17. (Stiles, Report U.S.A. Bureau of Agriculture, 1901.)
Diagnosis. In forming a diagnosis we meet with the same difficulty as in the case of the pig. It is always easy to examine the tongue; but when visible lesions are absent diagnosis in the case of the ox remains doubtful and problematical even more than in the pig.
In the carcase, diagnosis is much easier. The cysts are sought for, as in the pig, by making sections of muscle, those usually selected being the pterygoid, cervical, cardiac, and psoas muscles, and those of the quarters.
Prognosis. The prognosis is grave, not indeed for the infected animals, which seem little injured by the parasite, but for human beings, who run the risk of contracting Tænia inermis by eating insufficiently-cooked meat.
A temperature of 115° to 120° Fahr. destroys the cysticerci, but in roast meats the central temperature of the mass always remains below this figure.