Relapse, Relapse, Relapse
In this day of immediate media, I should have posted July 20th. Suffice it to say that one of the relapses was mine, in Lyme Disease. With the number of changes coming to the EPM world, I’ll try to keep the blog more current.
I sent a Fudge blood sample to Pathogenes to enter him in a study. This was a study for horses that had previously had EPM, but had been treated and recovered. I was happy that Fudge had recovered to the point where I took him for his first lesson. What I got back was that he was in the process of a relapse. I had both a SAG1 ELISA and a Lymphocyte Proliferation Assay run on his blood. It showed formation of a very low number of lymphocytes, and a slightly higher SAG1 titer. Before I could get the diclazuril shipped to me, Fudge had symptoms.
The relapse came about 15 months after his initial diagnosis. We do not know if this was a replapse or a re-infection. We started Fudge on a mix of diclazuril, sulphadiazine, and pyrimethamine. I got a prescription for three months of treatment. I had previously used just diclazuril, but wanted to see if the S/P would help. I did not like having to give the medicine on an empty stomach.
Fudge had a Mayhew score of 2.0 during the worst of the infection. He certainly was unstable when trying to trim his feet. He dropped much of his food and dragged his rear feet. As the long summer months wore on, he slowly improved. After 2.5 months of medicine, Fudge showed some worsening of symptoms. These were subtle differences in the way he moved, but seen on a daily basis, I could see them. He was dropping more food, which was measurable. We sent another sample for tests. Fudge was having a relapse while still on the medicine.
Anti-protozoal treatments kill or stop reproduction of the pathogens to a degree where the horse’s own immune system can kick in and finish the job. Reading the drug inserts the drug only kills about 95% of the protozoa. The horse has to eliminate what is left of the infection. Fudge was not relapsing due to the drugs. His relapse was a sign that his immune system was not able to fight even small numbers of the pathogens.