Zyrtec for horses

Yes, but that’s at the higher dose. There are pills now claiming to last 24 hours, so they would only need to be fed once a day.

My mare just eats them mixed in her breakfast (speaking of which… it is soon time to put her back on them. As soon as anything is blooming in the spring, she gets snorfly.) I wouldn’t put them in a soaked meal, though.

1 Like

I’m not sure if you meant to quote me- I mentioned Ramard’s Total Respiratory, which is a syringe gel formula. This sounds like you’re asking about the high end dose for Zyrtec. Yes, this is true. This is why getting it at Costco is a great idea- they’ll sell you 365 pills for $15. :slight_smile: They’re little pills, smaller than your pinkie nail, and they dissolve well in liquid. My horse just eats them. My guy maintains for most of the year on 10 pills BID but develops tolerance towards the end of summer, so I do have days where I double-dose him at 20 pills BID.


Why not?

I give mine in a tiny bit of soaked feed and then give a proper meal later because I want to see with my own eyes that every last one has been devoured, and not slopped over the edge of the feed tub as can happen with a larger meal, but I’m curious if your reason is similar or there is something about getting them wet that you feel could alter their potency or ??

Our vet is going by 10 mg per 100 pounds body weight. Each pill is 10 mg. Perhaps that’s the low dose, though. They are tiny pills.


So far, no trouble with her snarfing them down with a bit of senior feed. Thanks for the help!

1 Like

My old heaves horse was on 300mg of Zyrtec per day for years. It really seemed to give him some relief, and I never noticed any side effects. He happily gobbled them up in his grain. I bought the generic on Amazon for $20ish for a 500ct bottle if I recall correctly? I’m sure some FDA agent somewhere was suspicious of someone ordering 3000 Zyrtec pills at a time. :joy: I just portioned them into tiny plastic containers from the dollar store and put them in his SmartPak drawer. Easy for barn staff to dump a dose into his grain AM+PM and we didn’t have to count out 15 pills at every feeding.

1 Like

I wouldn’t soak them, but putting them on top of or lightly mixing them in a soaked meal is no problem

.2-.4mg/kg is the studied dose, so the low end of that is 100mg/500kg (1100lb). 10mg/100lb works out to 110mg for a 1100lb horse, so it’s pretty similar


Mostly because they taste bad… so if they dissolve in soaked feed, the horse may Just Say No. Mine did, anyway.

My picky pony slurps up her handful of mush. Even in the morning when she generally refuses breakfast (because she has more important things to do like GO OUT!!! and she is full of hay from eating all night) she will happily slurp up her handful of mush … and then make her demands to GO OUT!!!

That said, she will not eat them out of my hand like she will eat Previcox so the taste that I don’t notice when I take mine is apparently A Thing for her, but is masked by the tiniest bit of feed.

1 Like

Oy, I didn’t…I’m still used to the old forums… Sorry!

But also thank you for the reply! I just wanted to get a grasp on it before I speak with my vet Monday. Pollen is OUTRAGEOUS here right now, and I’m thinking my guy could use some relief, but it may not be the right line of thinking for him. He seems to be fine with the pollen but when he was really struggling, the Ventipulmin helped immensely. Since that’s a totally different class of drug, I’m wondering if that would be “allergies” or something more “clinical” (for lack of a better term).

1 Like

Bumping this up because my vet suggested we try this for my early stages IAD horse. She suggested about 12 pills 2x a day, which is more on the .2mg/kg side of the range.

Although his BAL shows possible allergy cause, the allergy seems to be to smoke and ozone moreso than dust or pollen given that he was totally fine in a different location for months that had plenty of dust (although he was outside more) and pollen. I already started nebulizing with saline which helped for a while, but even with AQI below 100, he’s having trouble lately. They want me to continue that. I also have a hay steamer that my boarding barn won’t let me use :anguished:

If he doesn’t have a good response in 2 weeks, they want to do another BAL and consider steroids. This horse is not really one I’d be keen on giving regular steroids. Are those who are doing .4mg/kg of Zyrtec doing that once a day or twice?

1 Like

Me! My vet had me start with 10 pills 2x a day and then once I noticed an improvement I went down to 10pills 1x a day. The way she described it to me was that Zyrtec works more long term so that’s why you can get away with the 1x a day. Every one in a while I go back to 10pills 2x if the air gets really smoky though.

Mine went on it during the fires last season and then stayed in it all winter due to the dust in the hay. It was almost like the fires last year started it and then she never fully recovered and would still have a residual cough if she wasn’t on Zyrtec. It makes a huge difference for her. Now my mare is on pasture so no dust, and no Zyrtec needed but I’m sure in the next few weeks when fire season gets bad again I’ll put her back on it.

For your mare’s size, 10 pills is probably about .2mg/kg right? That’s encouraging that you could get by with that dose 1x a day sometimes.

We used it for my old WB gelding who had mild IAD. He was ~1300lbs (590kg). We dosed him with 300mg per day (30 of the 10mg tabs) split into AM and PM.

If I did the math correctly, it’s actually more like 0.5mg/kg, but it worked for him.

Correct. I asked if there’s any risk in doubling it when I need to and my vet said no, I’m perfectly fine to do 20 pills/ day vs 10 but if she can be comfortable on 10 to try that first. So right now when the air is clear and she’s not on any hay she gets nothing, when she’s on hay she gets 10 pills a day, when I cannot see the mountains on my drive to the barn because the air is so bad she gets 15 or 20.

Just an FYI for anyone else. In desperation I put my mini on 1 pill twice a day. I was a bit worried, vet said she hadn’t used it on any miniature horses. Although I have a LARGE mini. She had bloodied her ears and rubbed out her tail. Within two days she was back to happy and everything is healing. It’s wonderful!


A 200lb mini (90.90kg) could easily get 18mg twice a day at the low end of .2mg/kg, so that’s essentially 2 of the 10mg pills, twice a day. So you’re at half that, and probably less than that if it’s a large mini. Glad it worked well!

Update on my mare. She’s doing great on Zyrtec, even through this nasty late allergy season.


My horse has been on Zyrtec now for 4-5 days. Plus nebulizer with saline. We can w/t/c and jump some small jumps again with mild exercise intolerance, meaning he will now clear the junk out of his airway relatively easier, does need some more breaks but not tons, and has more of a willing to please attitude, just got to keep the work short and to the point before he gets too tired.

Before Zyrtec, cantering was almost impossible. He was anxious anytime I thought about having any sort of contact and would object (not his usual attitude). Could not make it through 1/3 of his usual warmup without needing a break. Good luck riding with any sort of quality at all after what should have been the warmup.

Very hopeful we can continue to manage and don’t need steroids. :crossed_fingers:


Do you have the flexineb? Is it worth it? The Zyrtec helps my mare a lot but since we’ve had no precipitation the dust is out of control at our barn and I think I need to look into more options.