NOTE ON 'PINK-EYE' IN HORSES 
C. BALFOUR STEWART 
- - - - • .... . AND 
RUBERT BOYCE 
During several weeks of the winter of 19CO an epidemic of ' Pink-eye ' raged 
among the horses of Liverpool, assuming, at its height, so serious proportions that 
it was no unusual occurrence for 20 to 40 dead horses to have to be dealt with in 
one knacker's yard of the city. 
The onset of the disease was very insidious, and the fatal termination often 
extremely rapid, for there were many cases in which the animals dropped down dead 
in harness. That the disease was of an infectious nature was evident from the fact 
of its running through a stable, and it was recognized as such in the treatment, for 
the affected animals were always isolated in those stables which were under proper 
veterinary charge. 
Amongst those who had to do with horses there seemed to be a general 
opinion that the disease was the same as influenza in human beings, but, on enquiry, 
we were unable to meet with any instance of a case of influenza occurring from 
contact with sick horses, nor were we able to separate a microbe in any way similar 
to that of Pfeiffer. 
An infectious disease of this nature, involving not only heavy loss on team 
owners but also considerable suffering to the animals, particularly those which were 
driven with the disease already on them, is one imperatively calling for investigation 
to discover the micro-organism concerned, and, if possible, to devise some means for 
conferring immunity. 
Unfortunately for our investigation the epidemic came to an end somewhat 
suddenly, but we think it not uninteresting to put on record what few observations 
we made, with a view of prosecuting the enquiry further should an occasion again 
present itself. 
Seven horses in all were examined, and the results of our observations are 
as follows : — 
Horse 1. Suffering badly. A small quantity of blood was incubated in a 
sterile test tube, and another portion was inoculated on to the usual cultivation media, 
but no growth was obtained on any of the tubes, and the blood remained sterile. 
Horse 1. Convalescent one week. The blood clotted very rapidly : it was 
likewise found to be sterile. 
