Paludism in Dogs, etc. 579 



carbol thioniii blue or methylene blue, but not readily with 

 hsematoxylin. The dog's blood, containing abundance of para- 

 sites, failed to infect horse, sheep, ox, cat, fowl, Guinea pig, 

 rabbit, rat or mouse (Robertson). 



Robertson found the ticks on every affected dog which had 

 contracted the disease by simple exposure and which came nnder 

 his observation. Specimens sent to Neumann were identified as 

 Hsemaphysalis Leachi. Mature ticks from an infected dog were 

 preserved and their eggs hatched in an incubator. The resultant 

 six legged larvse, placed on susceptibile puppies a month old 

 proved harmless and no protozoa appeared in their blood. This 

 was repeated when the same generation of ticks had reached the 

 stage of nympha, and it was after two months from the hatching 

 that the ticks, now mature, when placed on the same puppies 

 conveyed the disease. On the thirteenth day the temperature 

 reached 105° F. . and the red globules swarvned with parasites, 

 many single globules containing no fewer than eight. They were 

 of various shapes, spherical, pyriform or cloveshaped many 

 tapering finely toward the ends like an oat. The puppies died 

 respectively 14 and 18 days after infection. 



Experiments made on other dogs with the larval and mature 

 ticks, fully confirmed the conclusion that the immature insect 

 was harmless. A 14 days old puppy infected by mature ticks 

 died on the nth day .so that the immunity of the other puppies 

 cannot be due to a milk diet, as in the case of calves and Texas 

 fever. Intravenous inoculation with the infected blood invariably 

 conveyed the disease. 



Symptoms. On the third day after inoculation the dog is dull, 

 prostrate, apathetic and drowsy, refu.ses food and shows thinst. 

 Temperature may reach 103° to 106° F. On the fourth day 

 the mucosae assume a yellowish tinge, and by the fifth this has 

 encreased to a deep chrome yellow, which involves any white 

 portions of the skin as well. Hsemoglobinuria is now well de- 

 veloped, the liquid being often as dark as claret, and the patient 

 may lie perfectly prostrate, giving off an offensive odor from the 

 skin, lungs, and especially from the mouth. The tongue is 

 furred, the teeth dirty, and the gums may be congested or even 

 ulcerated. Emaciation advances rapidly. The temperature may 

 oscillate from day to day or it may rise steadily to a climax, and 



