24 Poisonous Arthropods 



It seems clearly established that the bite of certain ticks may 

 cause a temporary paralysis, or even complete paralysis, involving 

 the organs of respiration or the heart, and causing death. In 1912, 

 Dr. I. U. Temple, of Pendleton, Oregon, reported several cases of 

 what he called "acute ascending paralysis" associated with the occur- 

 rence of ticks on the head or the back of the neck. A typical severe 

 case was that of a six year old child, who had retired in her usual 

 normal health. The following morning upon arising she was unable 

 to stand on her feet. She exhibited paralysis extending to the knees, 

 slight temperature, no pain, sensory nerves normal, motor nerves 

 completely paralyzed, reflexes absent. The following day the paral- 

 ysis had extended to the upper limbs, and before night of the third 

 day the nerves of the throat (hypoglossal) were affected. The thorax 

 and larynx were involved, breathing was labored, she was unable 

 to swallow liquids, phonation was impossible and she could only make 

 low, gutteral sounds. At this stage, two ticks, fully distended with 

 blood, were found over the junction of the spinal column with the 

 occipital bones in the hollow depression. They were removed by 

 the application of undiluted creoline. Though the child's life was 

 despaired of, by the following morning she was very much improved. 

 By evening she was able to speak. The paralysis gradually receded, 

 remaining longest in the feet, and at the end of one week the patient 

 was able to go home. 



There was some doubt as to the exact species of tick implicated 

 in the cases which Dr. Temple reported, although the evidence 

 pointed strongly to Dermacentor venustus* Somewhat later, Hadwen 

 (1913) reported that "tick paralysis" occurs in British Columbia, 

 where it affects not only man, but sheep and probably other animals. 

 It is caused by the bites of Dermacentor venustus and was experi- 

 mentally produced in lambs and a dog (Hadwen and Nuttall, 1913). 

 It is only when the tick begins to engorge or feed rapidly, some days 

 after it has become attached, that its saliva produces pathogenic 

 effects. 



Ulceration following tick bite is not uncommon. In many of the 

 instances it is due to the file-like hypos tome, with its recurved teeth, 

 being left in the wound when the tick is forcibly pulled off. 



*According to Stiles, the species occurring in the Northwest which is commonly 

 identified as D. venustus should be called D. andersonii (see footnote, chapter 12). 



