Zyrtec for Seasonal Allergies *UPDATE - ventral edema?*

[hybriseris]

My 14yo OTTB lease has been struggling with intermittent hives/runny nose. The vet suggested giving her Zyrtec morning and evening for a few weeks and it does seem to have helped bring down the hives almost completely. It’s been about two weeks now, and I think I’m noticing a change in her under saddle.

The last few rides she’s seemed less coordinated, and has had less energy. Nothing necessarily troubling - just some stumbling up front, and reluctance to do work she’d usually be all for. The Zyrtec is the only change I can pinpoint since this behavior started so I’m considering it as a possibility.

I tried looking up other threads on the forums in regards to drowsiness in horses taking antihistamines but wasn’t able to find much so I figured I’d ask you all if anyone has experience with these meds causing their horses to be different under saddle?

Thanks in advance!

[SinMiedo]

I’ve never used it in horses, but some people experience experience severe drowsiness on it. I’ve had patients do fine on it, but I once slept through my own (very raucous) birthday party after taking one, so I’d say it’s totally plausible that your girl could be having a similar response.

[Gardenhorse]

My horse is on Zyrtec for respiratory issues and I’ve never noticed any difference in her behavior (other than reduced coughing).

[flexion]

Yes, it can have a sedative effect and explain the behavior you’re experiencing. My vet initially prescribed 2 weeks to get through the flare up.

[going_gray]

A few years ago I gave my mare Zyrtec twice a day in her feed during the summer to see if it would help her coughing. Vet and I thought she had allergies. It didn’t help her at all. I think it turned her into a horse zombie as I was not using anything else as a supplement.

She had no energy at all and was dead to my legs completely. I had to tap her with my dressage whip to move her forward and then she bolted like I had used a cattle prod. Stopped using it and wouldn’t use it again.

We’ve figured it out that my mare doesn’t have allergies but sensitivity to dust during our dry summer months and the Zyrtec doesn’t help that at all.

[hybriseris]

Thanks so much guys! I would assume it’s sort of like people - some horses feel drowsiness, others don’t, from what I’m reading.

Unfortunately I went out this morning and the poor thing is positively covered in hives so, back to the drawing board anyway! I’ll be keeping an eye out to see if theres any change now that she’ll most likely be switching to a different treatment once I hear back from the vet.

[wildlifer]

Yes, horses will vary in their responses to things, just like people. I have had good results with hydroxyzine for horse allergies & it’s fairly inexpensive & easy to give (just open capsules & sprinkle on food, it’s a tiny amount so no taste issues). Of course, it can have a similar effect, but sometimes just a different medication in the same class can help.

I did always kind of laugh when my horse’s hydroxyzine bottle had a big sticker on it warning “not to allow this patient to drive or operate heavy machinery while taking this medicine,” as I generally don’t allow my horse to drive anyway, LOL, but now I see that horses can get drowsy too!

[quietann]

I had my mare on Zyrtec for quite a while but it wasn’t doing enough, and yes I think it made her a little sleepy. I tried hydroxizine and that was worse.

I’ve actually ended up using a herbal product with her, and it works better than the medicines did, without the side effect of low energy. I am not one to rush to use herbs. It’s Ranch Life Naturals Allergy Blend. Note: my horse doesn’t show, so I don’t have to worry about “testing.”

[TMares]

You might consider spirulina for allergies. It stinks, fair warning! And try the pellets not the powder.

[Critter]

The vets had me put my older gelding on Zyrtec for summer allergies he started having (runny eyes, clear runny nose)…he was on it just a few weeks and had a sudden very severe episode of laminitis with major rotation in both feet. He was likely Cushings, though he never tested positive over the years. I always wonder if starting the Zyrtec and the founder had some connection, or was just coincidence. Either way, the timing will make me cautious about going the Zyrtec route again.

[ABookworm]

I have my ASB mare on Benadryl in the summer for her bug and pollen allergies. We tried Zyrtec and she seemed lethargic and just off so I switched.

The Benadryl doesn’t completely take away her allergies but it’s tolerable for her now. The biggest drawback is that I do have to feed 9 pills a day and shes become a master at eating around them. At the end of the summer we were feeding her the pills by hand mixed with some senior feed.

[hybriseris]

Thanks everyone who’s weighed in since my last message!

She’s been off the Zyrtec for about a week, switched to Benadryl. Today was the first I’ve been able to hop on as the hives are almost completely gone and the difference is night and day. Interested in the work, no stumbling. Hopefully this regimen will work for her as needed, as this is the first time the hives have popped up in the winter. They usually seem to be an autumn issue.

[hybriseris]

Thanks again for the replies all! Hives are still under control save for a few here and there but new development.

Discovered a large lump on her belly today. Doesn’t bother her when I touch or press on it, didn’t get larger or smaller with exercise. Looks like a ventral edema from what I can gather. Any chance this is related to her allergic reactions or should/when should I have the vet take a peek?

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[Mango20]

Yes, this is almost certainly related. It’s probably the inflammation from the hives migrating to the lowest point. My pony had a spot EXACTLY like that after his hives. The vet said don’t worry, it’s just gravity. It got bigger. The vet continued to say I shouldn’t worry. Eventually, it went away by itself, but it took a week or two since it was so large and inflamed. It did not bother the pony at all, and he even went to the Pony Club show jumping rally looking worse than yours. I had the vet email me a note to show to horse management if anyone questioned whether he should be there.

[hybriseris]

@Mango20 Thank you! She’s getting her spring vaccinations fairly soon so I should be able to have it looked at either way, but gives me peace of mind in the meantime to know this looks familiar to your own situation.

[enjoytheride]

Every time I’ve seen ventral Edema it’s been heart failure. I would have your vet out.

[hybriseris]

@Mango20 Oh wow, yup - that’s spot on. It’s a little bit smaller today, and so are the hives. Really interesting!

@enjoytheride I definitely thought of that as well! But she has no other symptoms of heart failure so far. If anything her performance has been getting better, no coughing, etc. The vet will be out to do her vaccinations next week and will check her over then but I did send the picture I attached to this thread to her and for now it seems most likely it’s the allergies considering the timing.

[fourfillies]

I had a mare have a serious urticarial reaction (=big hives) to sulfa. As her hives resolved she had transient ventral edema. Gravity is a powerful force.