Splitting Vaccine Routines?

For those of you that have horses reactive to vaccines, I would love your input. I got my boy in summer of 2020. Our first round of fall vaccines that year spiked a fever/high respiratory rate with him and set the tone for what to expect from there on out. This round of spring vaccines were the worst as far as fever temps. Other than the fever, he was a little fatigued but eating/drinking/peeing/pooping/alert. No swelling or heat at the injection site and he had no problem moving his new around. Resp rate was normal.

3/30 - 8PM preventive full dose banamine
3/31 - 1PM - preventive IV banamine with 6 way
4/01 - 6:30AM - 105.2/104.7 fever - gave full dose banamine
4/01 - 6:30PM 100.3 - full dose banamine
4/02 - 7:30AM 99.5 - no medicine administered
4/02 - 1PM 103.7 - called vet; per vet gave additional full dose with the direction to only give half doses from there out if fever came back or Equioxx as to try to prevent gut issues.
4/03 - 4:15AM - 100.3 no medicine administered
4/03 - 7:15AM - 99.8 no medicine administered
4/03 - 10AM - 100.1 no medicine administered
4/03 - 5PM - 101.3 no medicine administered
4/03 - 9PM - 100.2 no medicine administered

I had been hesitant to split the shots up due to the possibility of having him have reactions more than twice a year and up until spring, it seemed like getting ahead of things with banamine was doing the trick. The vet and I both agree that splitting them up will be our best course of action at this point.

Here for Spring:
*Eastern/Western Encephalitis
*West Nile Virus

For Fall:

  • Rhino/Flu
  • Rabies
  • Potomac Horse Fever
  • Strangles Intranasal (Pinnacle)

For those that split up vaccines, what is your timing with shots and your routine (IE giving banamine etc). I have seen people run titers for dogs and vaccines; is this done with horses too/would that be worth looking into?

I do plan on trailering him places this year, so I’m not sure what we could forgo either. At least he is good about getting his temp taken!

I have one that gets a high fever and so sore with combo vaccines that she can’t drop her head to eat or drink. I split them up after that, and switched to Vetera, and she’s had no further issues.

In general, I just do everything a week apart. Works fine. No fever, no soreness. No need for banamine.


My guy’s reaction is lethargy and neck soreness. Through trial and error we found that minimizing the number of diseases vaccinated against at a single visit is best, and that he seems to have the biggest reaction to flu/rhino. Example:

Spring 1: flu/rhino (+/- WNV, draw titer for strangles)
Spring 2: Eastern/Western/Tetanus, Potomac (+/- WNV - when I lived at a farm that also required the botulism vaccine I did that here.)

EWT and flu/rhino together make a sad horse. Separated this way, he might feel a little low, but his appetite is good and he’s responsive to stimuli even if he dozes more. So, I don’t feel he needs Banamine when we split them out- he needs a day off, a neck rub, and extra mints, which have medicinal value. Now, your guy has much bigger reactions than my fellow, but he’s also getting a bunch of vaccines at one time. I would definitely talk with your vet about splitting them up. It might be the difference between wanting bed rest and chicken soup for 3 days and lying on the couch watching Netflix and drinking tea for a night.


My horse gets bad reactions but hers are in really bad swellings. I actually don’t spread out the vaccines but I don’t do combo shots. So in the spring she got 3 different shots on the same day. I do banimine the day before, the day of, and 3 days after.

I think the advice to do them a week apart is smart. But I think the biggest thing will be avoiding those combo shots…

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I have to run titers on my guys (minis). They are not 100% accurate due to interpretation guidelines being vague (for lack of better word) but they will give a good idea where things stand. Both my minis get quite sick from vaccines, with high temps, sore necks (inability to put head down) and very hot feet even when pre-treated with banamine. Their temp usually starts about 24-36 hours after the shot (depending on the mini) and lasts a few days. Giving the injection in the rear end helped with the stiffness/soreness but not the hot feet. We also tried breaking up the doses, but that didn’t make a difference.

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I would definitely do PHF in the spring-- if you are giving Tetanus separately from E/W you could do that in the fall. I like to do WNV and PHF in early May just before the bugs get bad here, that way they are at max efficiency.


Doing the Potomac vaccine in the fall would seem to be counterproductive if you’re in an area where the insect population is killed by frost in the fall, as the previous poster mentioned.

(I had a former BO get her knickers all in a knot when she heard that PHF was present in our area - it’s actually indigenous to some locations here that are near water. She wanted all the horses in the barn vaccinated ASAP. It was mid-October and by the time the horses would have received their first shot plus the booster, it would have been well into November and we usually have had some pretty definite frost episodes by that time. When I pointed this out to her, plus the fact the vaccine isn’t all that effective and that PHF had been in the area for decades, she quietly withdrew her request.)


Lots of great advice on here. My vet will not give any combo shots are they are most reactive to those (plus if they have a reaction, you will never know to which one they are sensitive to if they are a combo shot). I do tetanus on one side of the neck and rabies on the other side. Then wait a week and do rhino/flu on one side and west nile on the other. We don’t really get anything else here that I need to vaccinate for, and this has worked really well for my ponies. I do give bute just afterwards for a day as per my vet. They seem to be sore for the tetanus (neck sore) and get some swelling from the rabies as the equine version is on b/o and they seem a lot more reactive to the small animal one (as in swelling).


Thanks everyone for the feedback, it is super appreciated and really helpful.

I like the idea of doing one on each side; that seems like it would help to identify which ones he is more reactive to.

He did start to show more of a sore neck yesterday and had a little tightness at the injection site. I do mobility stretches with him most days and he could only reach around about a third of the way he normally does on both sides. That was actually kind of nice to be able to have that as a gauge. I hand walked and trotted him a bit and that seemed to help loosen him up. Poor guy!

Yes, its a great idea to do some light work as well.

Our vet always told us to work them lightly the day they get their shots. This helps to move it away from the injection site and they do seem to do and feel a lot better if we do that. I do the same thing for myself and for my puppy if I/we happen to get any shots. It has done well for us so far!


My vet will not allow shots in all one appointment, they must be split. I do 3 way and WNV one appointment, and Rabies/Rhino another appointment.

I have never had a reaction until this year after the 3way. Bilateral swelling at base of neck by the withers. no temp, but tender neck for almost a week.

One other thought, though I think this is purely anecdotal…some horses do better with shots in their butt rather than their neck. If it’s swelling and soreness this makes obvious sense since that’s a bigger muscle group. But I know some who get fever and lethargy from vaccines and also do better with shots split up on both sides of the butt. If your horse is well behaved for shots this could be a good option. Of course, if your horse is not great for shots, the vet may not want to give them in this location!

Mine get vaccinations in their hindquarters. We do the cocktail EEE/WEE/tetanus/WN in one visit, and Potomac and EHV/flu separately a week or two later.

I used to do Rabies in the fall with the EHV/flu but the horse Rabies vaccine is no longer available as a separate shot. My vets had to use cat Rabies vaccine last year. The manufacturer of the four way cocktail added Rabies to it for this year and my vets recommended skipping Rabies last year rather than repeat it 5-6 months later.

I have known some people who literally split the individual vaccine - half on day one, the other half on day two. I also encountered a vet who autoclaved the needle for horses with bad reactions to certain vaccines (Rabies in the one I knew). This removed the manufactured coating and for some horses it significantly reduced the reaction.


Fall vaccine appts are scheduled; Sept 29th for intranasal flu/rhino (and a dental) and Oct 13th for PHF and rabies.

I was re-reading through the comments here and I will ask about the timing on PHF; the only thing with that concerns me there, is he is already getting hit with 6 vaccines (and highly reactive) in the spring which is a lot (and a lot to split up) if the PHF in the fall covers him for a year. If nothing else, we will get data points on both vaccines as far as his sensitivity goes and can use that for future planning.

I have a boarder friend that is a vet tech now and she had mentioned that sometimes Zyrtec can help with vaccine reactions with some horses. He is on that now for seasonal allergies so fingers crossed we get a little help from that too.

The way I understand it (and I am not a vet, related to a vet, play a vet on TV and have not stayed at a Holiday Inn Express ever) PHF is one of the less affective vaccines and has a shorter time frame of effectiveness so giving it in the fall for next summer does not make sense.

My horse vet now recommends moving PHF to the beginning of summer. Yes, that means another farm call. We do our spring shots in March/April, then do PHF in June/July. Maybe consider simply doing something like that for your PHF and maybe something else.


But, horses who are vaccinated, and who still contract the disease, are almost always so much easier to treat with fewer and lesser degree symptoms, so it’s still worth it where it’s a problem.


Yes to this!


Ok got it. Just found this from Ohio States Vet school too

“ Potomac Horse Fever (PHF), caused by infection with
a bacterium called Neorickettsia risticii, is transmitted to horses
through aquatic insects (such as caddis flies and mayflies) and has its peak
incidence in the months of July, August, and September”


I’ll call back and see about just getting the rabies in October. Are rabies/PHF generally in a combo shot? Maybe that’s why they do it that way. Are there any other spring vaccines that could be done in that same summer time frame?

this triggers a memory, and I’ll just put it here while I go double check. I SEEM to recall that this combo lowered the immune response to the rabies part :expressionless: Now I’m off to check and will update what I find

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I can say that at the appointment I do PHF my horse only gets PHF. So, at least my vet does not do rabies with PHF.

Rabies at the Spring appointment.