38 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
be hardly any noticeable rise during the course of the disease. The temperature may 
sharply rise, this is usually in conjunction with an increase in the number of the 
parasites. The parasites may be noticeably scanty, or they may, as we observed in a 
few cases, be present in large numbers — ten to forty to a field. Death is usually 
preceded by a fall in temperature, sometimes the parasites are almost absent before 
death, at other times they are largely increased in numbers. 
The symptoms so often associated with Nagana and Caderas are seen in rabbits 
infected with the Surra parasites. The oedema of the ears, perineum, the swollen 
testicles, the tumified vulva, the discharge from the penis, eyes, and nose ; all these 
are present to a greater or less extent. Anaemia is present but not markedly so. 
Loss of weight is a constant feature of the disease. Young rabbits are easier to infect 
than adult ones. The duration is lessened, the parasites are generally more numerous. 
Guinea-Pigs 
Incubation is six to eight days. Duration, forty days to two to four months. 
The parasites at first are present in scanty numbers, later in the disease they 
increase. Sometimes they may almost disappear from the blood and remain so for 
some time to augment once more. The rise of temperature is usually associated with 
the appearance of the parasites, the temperature is never very high. Anaemia is not 
a prominent feature. Loss of weight occurs, being especially marked when large 
numbers of trypanosomes are present in the blood for some time. Oedema has been 
noted on a few occasions. No animal has recovered without treatment. 
Cats 
After intraperitoneal inoculation infection takes place in eight to twelve days. 
The infection is usually long continued, the parasites are scanty in the blood. The 
chronic form of the disease in this animal may last six-and-a-half to eight months. 
There is a certain amount of anaemia associated with a slight loss in flesh ; towards the 
end these symptoms become more pronounced. A discharge from the eyes and nose 
has been observed. One cat showed quite a pronounced oedema of the perineum. 
The disease in kittens manifests a severer form, the parasites are usually numerous, and 
the duration of the disease may be only four to six weeks. The autopsy shows in 
these chronic cases very little of interest. The organs appear very little changed. 
The peritoneal and pericardial exudates, if any, are scanty and usually no trypanosomes 
can be found. Kittens show an enlargement of the spleen and glands, their blood 
and peritoneal and other exudates usually contain parasites. 
Dogs 
Several animals have been inoculated. In all cases after subcutaneous injection 
the parasites have been found in the peripheral blood in seven to nine days. At first 
