I apologize for going further down the EIA track, but have history with the disease that may be of interest. I worked at a polo farm for several years. About 60 horses in the summer; 15 stayed north in the winter while the rest went south. There were sometimes acquisitions and/or sales of horses.
One summer day it was noticed that a green pony was just acting “flat”. Within a day or two it progressed to weakness and lameness. Vet called out: turned out horse had fractured its hip on the stall door when it lost its balance, but the reason for that was a mystery until the bloodwork showed significant anemia. Vet ran a Coggins and it was positive.
Next steps: quarantine whole farm and test and retest all of the horses. Ultimately 4 were positive including the green pony, but none of those 4 horses had left the property in over two years. Further investigation identified an Argentine import that would lose condition every autumn. This mare would just drop weight and develop “bird spots” all over . In a month or so it would pass. All Coggins tests including from her importation two years prior were negative. (And it should be noted that the whole barn was tested at least twice a year because so many went south.) Mare’s samples were finally found to be positive by another testing method that, at the time, was only done at a midwest reference lab. Her traditional Coggins remained negative.
So sometimes, no matter how rigorous you are, diseases will find a way. We were very lucky that no other horses were infected, and none of the positive horses had been leaving the property prior to diagnosis.
Now back to the original discussion.
