Hi all, I know this thread is a little old, but I ran across it after researching an experience I had yesterday with one of my mares. So I figured I should probably post it here. Here’s what happened with me yesterday. I have used other dewormers on this same mare in the past and have never had any problems until I used Zimecterin Gold.
The following is a timeline of events regarding my experience with Zimecterin Gold. I am not a veterinarian, but the treatment protocol I followed was given based on orders of a veterinarian I was in telephone contact with throughout the day.
00:00 — I administer Zimecterin Gold to two horses, both of them Arabian mares.
00:10 — Approximately 10 minutes after administration, mare #2 begins experiencing tongue swelling, obvious mouth distress, and profuse drooling of mucus-like saliva. She also appears generally lethargic. She will not eat. Mare #1 is fine.
00:45 — I contact my veterinarian for advice approximately 45 minutes after symptoms begin. I administer 2 grams of phenylbutazone paste via oral route. However, due to swallowing difficulties, she ends up spitting probably half of it back out. I continue to observe her for the next 2 hours. There is no sign that she’s getting any worse, but also no sign of any improvement. I consider giving epinephrine, but decide against it since there is no sign of breathing distress or other indications that this reaction is life threatening. Furthermore, she appears stable, even though she is not improving. She lays down a couple of times, but does not roll, kick, or bite, So I don’t think there is any colic involved.
02:00 — Approximately two hours into the episode, I contact Merial, (the company that makes Zimecterin Gold.) The technician I speak to there informs me that they have had rare reports of this happening, that she should be fine by the afternoon, and repeats the same advice the vet gave me (give her phenylbutazone). She gives me a case number and says she will follow up with me later that evening to check on how the mare is doing.
02:45 — Two hours after the phenylbutazone, she is not showing any improvement, but neither is she getting any worse, so I continue to refrain from giving epinephrine. I contact my veterinarian again for advice. I administer 10 cc of dexamethasone 2mg/ml via IM injection.
03:45 — Approximately 1 hour after dexamethasone injection, her condition begins to improve significantly. She is no longer drooling and she is starting to eat. Her tongue no longer appears swollen. But she still has obvious mouth discomfort. I continue to observe her. Mare #1 remains fine and has had no reaction at all to the Zimecterin Gold.
04:45 — Approximately two hours after dexamethasone injection, she is eating relatively normally, but still slowly due to what I assume is residual mouth discomfort. I believe the dexamethasone stopped the acute reaction, but she is still suffering from residual pain. I continue to keep an eye on her.
20:00 — Approximately 20 hours after the acute reaction began, she seems to be doing fine. She is eating normally and appears to have little to no mouth discomfort anymore. Mare #1 never had any reaction at all.
As of now, everything seems okay. Merial never actually followed up with me, despite their claim that they would. Again, I’ve used other dewormers before on this same horse and never had any reactions.
I don’t know how common or rare these reactions are, but I figured I should share what happened and what I did to deal with it. It definitely seems like there is still a problem with this particular dewormer that the company has not addressed. Needless to say, I will not be using Zimecterin Gold on any of my horses again.
I hope this helps someone.
