3 months from the start of treatment is part of Cornell’s rec – is waiting longer to re-pull blood better? How long does a horse actually need to show the most accurate new titer?
If a titer shows only minor improvement, but that titer is still in the positive range… would you treat again or wait a period of time longer and re-test?
If the titer is high it can take years to drop, and may never be negative again. We retest yearly. The horse that was over 10k is in the 4k ish range now, which I think is four years post dx and tx. Because the titer continues to drop, it’s not a positive test for her and requires no treatment.
I can’t imagine testing after only 3 months.
Thanks Simke.
Re the 3 months, this is where I got the info (from Cornell):
" For chronic infection stages (OspC-/OspF+): Follow-up testing with the Lyme Multiplex Assays can be performed as early as three months after starting treatment. It should not be performed earlier to give the antibodies time to decline. A successful treatment is indicated by a clear drop in OspF antibody values (≥ 50% of the pretreatment value obtained three months earlier). A treatment failure (persistent infection) or reinfection after treatment is indicated by OspF antibody increases, no or minor decreases or alternating antibody values (minor drop followed by increase after re-testing). In case of a reinfection, OspC antibodies will also become positive."
Link: https://www.vet.cornell.edu/animal-health-diagnostic-center/testing/protocols/lyme-multiplex-horses
Yeah I don’t think any of my vets approach it that way. It’s taken years to get a 50% decrease in OspF and no one is in the least little bit concerned about that. None have suggested treatment failure, or that we should be retreating. These are vets at large referral clinics, in Lyme country.
Gosh, I sure wouldn’t test 3 months from the start of treatment, considering many vets (including mine) like to treat for 60 days for a high OspF
In my case, I may never re-test unless she starts behaving out of sorts again. Before the 60 days was up, she had returned to her normal level of energy and engagement, and that’s all that really matters. My vet doesn’t really recommend re-testing if the horse is back to normal, there’s just not enough information out there on the relationship between the titer and the impact on the horse.
The OspF tells you there is or was a chronic infection, but that’s all it tells you. If you pair it with symptoms, then treat for sure.
It’s just not like, for example, anaplasmosis where there’s a direct relationship between titer and whether the horse is actually ill.
Thanks JB. In this horse’s case she was low positive Ospf. But she had symptoms. Since treatment her behavior does seem more pleasant but she is uncharacteristically tentative when moving around. That’s why we retested and yeah went with Cornell’s 3-month plan but we’re going to wait and see how she is a while longer. Part of me does wonder if 45 or 60 days of treatment would have been preferable but again, the positive was low so we did the 30
Yeah, we also treat with 60 days of mino.
Although I had a horse this year with a pos chronic Lyme titer that I thought was the cause of his weirdness, but he didn’t really improve with treatment. His EPM titer was barely pos but he’s improved greatly with EPM treatment. You might consider testing and treating for EPM.
Come to think of it she has lost some topline but then, what horse doing nothing all day wouldn’t lol. Also she is big and pretty strong and does not lose a modicum of balance on the turning test. At the same time it’s a thought, ty…
I have two out of three horses without screaming neuro symptoms but pos epm tests and improvement with treatment. The third did show neuro symptoms, briefly.
NQR can be EPM, apparently.
when did the 30 days end? I’d do another 30 days.
The EPM investigation is worth looking into. Compounded levamisole and decoquinate is what I’d do, as it supports the immune system and actively kills the protozoa, unlike Marquis which only suppresses reproduction in the hopes the horse will take care of the rest. AND, the compound is wayyyyy cheaper than Marquis
Ty JB!
I forgot to add - it wasn’t until maybe around 45 days that I really notice my mare’s energy changing back to normal. It’s also continued to improve after the 60 days was done which was a month ago
You’ve made this statement a few times, do you have the literature behind it? I’ve been able to find very little published, and it’s certainly not FDA approved for this use.
It’s not quite right to say that ponazuril “only suppresses reproduction” either. It looks like we don’t fully understand how it works, but it appears to have action on the apicoplast and mitochondria:
“Ponazuril is a triazine-based drug that acts to inhibit enzyme systems in protozoa or decreasing pyrimidine synthesis. It is specific for apicomplexan organisms because the action attacks the apicoplast organelle in protozoa. This action produces a specific effect as an antiprotozoal agent without affecting other organisms or the treated animal.”
“Toltrazuril, the parent drug, has activity on the mitochondria and respiratory chain of some avian coccidian parasites. Ponazuril may also have activity against the plastid body, an organelle of apicomplexan parasites that functions in amino acid synthesis, electron transport, and energy metabolism. A chlorophyll complex of coccidian organisms, not found in mammals, appears to serve as the receptor for this drug.”
https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/ponazuril
No, it’s not FDA approved, though Pathogenes is working on getting it there, at least last I knew, I hope they still are. They’ve been producing this for a good while as Orogin-10.
Having several friends who are well-versed in sciences (MSc, working for Ag departments, etc) who have down the EPM road several times, and conferred with several vets who have vast experiences with EPM and the various drugs, they all agree that this combo is more likely to produce better results out of sheer experience, and knowing what the 2 drugs do.
Maybe it’s not quite accurate to say it ONLY suppresses reproduction.
Marquis only “guarantees” an improvement of 1 score, which is fine if you’re at a 1-2, not fine if you’re at the higher end. It has failed a ton of horses who then were helped either totally, or at least greatly improved, with the compound. Maybe it actually does do some killing, but that’s not what the above vets think based on actual cases of little to no improvement, or quick rebounds after treatment was stopped
Sometimes we have to look at what’s working for the horses, rather than what the literature says should work, or what’s approved.
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