View Full Version : Just want to share my experience with Potomac Horse Fever

Jul. 21, 2010, 09:25 AM
Bunny caught Potomac Horse Fever. This is a deadly bacterial infection caused by snails, and mayflies.

But, I caught Bunny’s infection VERY early, so her prognosis is good, however, its been a frightening past 2 days. Ive been up 24/7 icing her back down and standing her in boots packed with ice. Her temp kept spiking to around 104. she is on IV antibiotics (oxytetracycline) and Banimine (fever reducer) and is now doing very well holding her temp around 100. she has one last treatment today.

All along she has been eating, drinking, and poo-ing normally (good thing she is a little piggy girl) which is GOOD the infection NEVER got that far.

Ive never been so scared in my life, losing her would have been permanently devastating.

Monday morning I started out to ride Bunny, but she was “just not right”, which prompted me to take her temp. it was 102.6, by the time the vet got there and started treatment it spiked to 103.6, and continued to rise until the treatment kicked in, and then dropped.

having her vaccinated earlier, catching it early, and jumping onto treatment like: NOW (even before the tests got back) was the key to survival. NOTE: if your animals are presenting: “just not right” please heed their warnings. it only takes a minute to take their temperature, and if you are in a high risk area, please booster for PHF it MAY help

thanks for reading

Jul. 21, 2010, 01:39 PM
Glad you caught it so early. :yes:

Jul. 21, 2010, 04:59 PM
I had a very similar experience. No one had told us that we had to booster in July-ish (based upon our spring shot schedule). This was probably 12 years ago. My mare got the last isolation stall at Cornell. Apparently there was an outbreak at a barn in my area so they started treatment before the tests came back. She fully recovered but some of the other horses from the other barn weren't so lucky :(

To a 13 year old (as I was at the time), that was super-scary. I sobbed all 2hours up to Cornell. Looking back on the events of the previous week, I was able to figure out almost exactly where she got it. I let her eat some swamp grass in an effort to encourage her to get into the pond.

Jul. 21, 2010, 09:10 PM
:no:I am so very sorry to hear about your horse! I know how frightened you must be. Good that you caught it early and got your Vet involved - your horse is really lucky that you noticed she was slightly off - really lucky! Sounds like you are really in tune with your horse! Best of luck - hope she recovers 100% quickly!

Wheel Whip
Jul. 21, 2010, 09:18 PM
Having lost one to PHF and having "Potomac like" issues in horses every year (with innoculations), you are doing exactly the right thing. The banamine also prevents the ednotoxins from being absorbed by the gut, triggering the laminitis. Please be aware they can be prone to a "backlash" founder up to 1 month after symptoms subside. Please talk to your vet about keeping Bunny on Banamine or Prevocox for a longer period of time. Few things scare me more that PHF. Hang in there!

Jul. 21, 2010, 10:32 PM
I had a very similar experience also. Last fall my gelding just seemed a little quiet. I took his temp and it was 101 something. I decided not to ride him that day and planned to go back out and recheck his temp after I got off work at 10 pm. Just before I left the barn owner called and he had a temp of 103.6 with hypermotile gut sounds. We started treatment that night for PHF. He was markedly better in less than 24 hours and seemed completely normal 48 hours after starting treatment. We were very lucky.

My horses are both vaccinated for PHF, even though the vaccine has very questionable efficacy. I feel the risks of vaccinating are minimal and if it might help, even to decrease severity, it's worth it.

Good for you for being observant! PHF is definitely going around right now...we have 2 at school at the moment that have foundered. :( Best wishes for a great recovery.

Zu Zu
Jul. 21, 2010, 11:17 PM
Glad Bunny is recovering ~ what a great and vigilant owner ~
Good information to know ~ thanks for posting ~
Jingles for some rest and recovery for Bunny and her owner.

Jul. 22, 2010, 08:41 AM
Ugh, I am going through this right now with one of my boarders. Horse came in very lame one morning. Nothing else seemed wrong. He had thrown a shoe 2 days prior and when farrier arrived right after morning feeding he swore it was just an abcess. Owner took farriers advice and just packed the foot and waited for the so called abcess to blow. Myself and one of my other boarders felt that the horse should see the vet just in case he was foundering, but the owner wanted to wait because the farrier told her that he was 100% positive it was an abcess and that it would blow over the weekend. 3 days later the horse was very lame on the other foot. I called the vet before even calling the owner cause I was sure he was foundering. He had a temperature of 103. Once the vet arrived she confirmed that he was def severely foundering. She ran bloodwork and confirmed he had potomac horse fever.
We started him on oxytet, banamine, and doxy. Poor guy was so sore that he would sit on his water buckets.
Luckily all of the meds worked wonders. It has been 4 weeks since he first was sick and he got to go outside for the first time last night. He was 100% sound and came in completely sound this morning. We are keeping our fingers crossed.

Jul. 22, 2010, 09:40 AM
thanks everybody for all the encouragement and jingles!

ive never been more scared in my life. ive been SO worried, I could barely breathe. didnt sleep a single wink since Monday. This mare means the world to me. ive owned her since she was 1 years old (7 now), Ive done ALL her training myself. she has always been everything ive ever wanted. I love her more than ive ever loved anything in my life, and I would go ANY lengths for her. I cant even explain how devastating it would have been to lose her.

the vet called yesterday afternoon, after Bunny's last treatment, and confirmed the Potomac test was positive. I let out a scream, and started crying hysterically (I think it was a relief thing) thanking GOD we did the right thing, made all the right moves. All I could think about was: "I could be LOSING her right now", instead of just having to ice her feet for a few more days.....

this da** PHF is SO stealth, and there are SO many strains. I honestly think that the vaccine helped reduce symptoms even if it didnt actually work.

Jingles to everyone who is now in this, or has experienced this (HUGS) I never thought: "it could happen to us"....

I guess you never know how frightening this thing is until you are the one under the gun

Zu Zu
Jul. 22, 2010, 10:05 AM
Jingles continue for Bunny to make a full recoevry ~ AO ~ Always Optimistic ~

Jul. 22, 2010, 12:08 PM
I just wanted to respond with my own experience. I am glad to hear Bunny is doing much better.

A few years ago, my horse had Potomac Horse Fever in October...so it can happen all the way through summer and into the fall, just an FYI. He started being off his food, and "not quite right." I took his temp and it was 102.5, then when the vet came out it was around 103.5. They started him on Tetracyclene right away, but I still ended up having to take him to MSU a few days later, because his gums/mucous membranes got bright red. When I got him up there, it was touch and go for the first 24 hours, and he had to have a plasma transfusion. I hadn't vaccinated him for Potomac Horse Fever that year, so I wonder if he got a more severe reaction because of this. Although, he never had diarrhea, just overactive gut sounds, and colitis. He is fine now, but it is a very scary illness.

Good Luck to all of those horses who get it this year, and just keep an eye out for it to get them treated quickly.

Jul. 22, 2010, 02:02 PM
My mare had PHF about 8 yrs ago. I noticed her NQR and called the vet who started treamtment immediately. She had been vaccinated for it . I had the complication of her being in foal. Thanks to very aggressive treatment from my vet she recovered and had a healthy foal the next spring

Poll Evil
Jul. 22, 2010, 04:28 PM
Dear Bunny,

Get well soon! Your person loves you so much and it is a joy to read about your relationship. :lol:

Zu Zu
Jul. 24, 2010, 09:57 AM
Bumping for a weekend update on Bunny ~ hoping she is recovering in an uneventful manner ~ Jingles & AO ~ Always Optimistic ~

Jul. 24, 2010, 07:37 PM
thanks ZuZu,

Bunny has been holding steadily at 100.5

Her poos are a little wet, not quiet "cow-pattieish" but, not her normal. vet says it could be because of the heavy antibiotics. so, she is on a probio now.

im still guarded and taking her temp every evening.

she is more and more like herself everyday

BIG HUGS to everyone who jingled. it means a lot to me

I pointed to Bunny yesterday and said (to my BF) "see THATS Bunny, shes back".. and he just didnt see a difference. LOL! I saw it though. plain as day to me.

Jul. 26, 2010, 10:21 AM
Yay for the improvement! It's so hard when the furry kids are sick. :(

Jul. 26, 2010, 10:49 AM
yikes! so glad you caught it early. i personally know 2 horses who got it and weren't so lucky :no: i do have a question, tho. OP and several ppl are commenting that their horses came in nqr but not really specifying where they were seeing the nqr-ness. was the horse lame, off its feed, sad seeming, what? phf is one of my great fears, esp bc we are so close to a creek O_o

Jul. 26, 2010, 12:16 PM
Posting this again from another thread with my experience:

6 years ago, we had a very wet summer, not so unlike what we're having this year [summer of 2009]. I had very recently (2 days prior) started my mare on a new supplement when she suddenly stopped eating her grain, but I chalked it up to the change in her feed. It smelled different, and she was a bit of a picky eater anyways. She was still eating her hay, grazing and drinking normally. Then she was unusually lazy under saddle that afternoon, and very slightly lethargic in the cross-ties, but it was pretty hot that day compared to the weather we had been having up until that point, so again, I didn't think a lot of it.

She wasn't interested in her dinner that night in the slightest. She didn't even come over to check it out. This was extremely unusual, and I called the vet with a heads up, and asked if she could stop by in the morning to check things out.

When I went out the next AM, there was diarrhea everywhere, and my horse was a mess. She was standing in the corner, with her head down, and was pretty much unresponsive. I made an emergency call, and my vet (bless her heart) was there within 15-20 min. We had to stomach tube her, gave her a bottle of gastroid and a whole bucket of water/electrolytes. Banamine, tetracycline as well as an IV. My vet all but told me to say my good-byes at this point, and I was devastated. I iced her feet 3x a day, kept her pain check, kept her in the shade, and pretty much had to play the waiting game. She made it, and much to my gigantic relief didn't founder, but she did lose almost 200 pounds within 5 days. It took me 3 months of careful hand-grazing and conditioning to be able ride her again, and a full year before she started looking like herself again. To this day, she's a hard keeper and has a nice stack of fluffy warm blankets for the winter. Her winter coat has never completely grown in since then.

Basically, if your horse isn't acting normal, even if it's not something major, call the vet. When in doubt, call the vet. I could have very very easily lost her that week, and it was not worth making excuses for the very subtle changes in her personality. I was only 16 when this all happened, but it was a huuuuuuge lesson learned!

Jul. 29, 2010, 08:49 AM
wow, there are VERY good stories here on this post... lessens learned... please take note to all the stories. I never did before... I DO now

I have another friend whos horse got PHF. and her winter coat never came back either. we were wondering about this.

Bunny didnt get to the point of being off her feed, grain, diarrhea, laminitis, colic, colitis, etc. it was more of a personality thing. she is seven years old and Ive owned her since she was 1. ive done ALL her training, and spend most of my days with her.

Im surprised that I even noticed anything at all, because the change in personality was SO subtle. no one else noticed anything wrong with her. she just was NQR to me. IDK what made me check her temp that day. it was a look in her eyes that just said: "hey, I dont feel very good today".

this scares the cr@p out of me. cause what if I missed something???? I would have had to say "good-bye" to her already. :(

Zu Zu
Jul. 29, 2010, 10:01 AM
So glad Bunny "is back" :) ~ thank goodness you caught her early ! :yes:
These stories are very helpful ~ glad to read this thread = this is what COTH is all about ~ people taking the time to report their experiences so others can be fore-warned and advised :cool:~ Jingles continue for Bunny and her owner :D

Jul. 29, 2010, 10:39 AM
Ugh! So this thread was linked to me cause I'm headed to a show in MD and the BM was insisting us to get the PHF vaccine. I did it years ago but its been 4 yrs since my horse last had it. My Vet said that if they had it a couple years ago a shot now would act like a titer however if they haven't had it she suggests not giving it now if they are traveling for 6 hrs. The first shot is not effective but the booster they get 4wks later is. She'd be more concerned with vaccine reaction if I give it now. Thoughts?? The horses will be stalled, we bring our water, and leave. The BM will quarantine the horses when we get back if we don't vaccinate.

Jul. 29, 2010, 10:49 AM
i do have a question, tho. OP and several ppl are commenting that their horses came in nqr but not really specifying where they were seeing the nqr-ness. was the horse lame, off its feed, sad seeming, what? phf is one of my great fears, esp bc we are so close to a creek O_o

What I noticed about my horse when he contracted PHF:

First of all, when he was in turnout, I found him in the corner of the shelter shivering. It had been a slightly chilly day, but not enough to make him shiver. So, I took his temp., and it was 102.5. I called the vet to come out, and within the hour, his fever jumped to 103.5. The night before that, I had the best ride of my life on him (and he is usually a difficult ride). Then, he can be somewhat of a biter, and during the time he was sick, he was very nice and loving. It's kind of funny now, but it was a little frightening at the time.

I did start him in the Tetracycline with the vet right away, but it took a week or two before he got better. Even after the Tetracycline was started, he wasn't eating or drinking very well, so the vet had to keep coming out and tubing him with fluids. He would try to eat grass when I grazed him, but would just keep rubbing his gums on the ground. Kind of like he really wanted to, but was too nauseous to take a bite. After about 3 days of this, and him not getting better...and then his gums turning brick red, I took him up to Michigan State. They gave him the plasma, and had him monitored 24/7. I hadn't slept much in the 3 days prior to this, so it gave me a bit of rest, but he wasn't completely out of the woods until he was there for 2-3 days. We knew he was getting better when he bit the vet at MSU. They were ready to get him out of there then! LOL!

And, I am curious now, he didn't seem to grow a very heavy coat this past winter, so will keep an eye out this winter. I ended up blanketing him last winter.

So, to determine if your horse is NQR, I think they all react differently. Just take time to notice if they seem a bit off compared with their normal personality. A horse that doesn't normally bite, may try to bite you and vice versa. And, take the temperature. A good indicator is a high temp that is over 102. Which is still kind of low for PHF. They can get to 104 or higher in some cases.

Good Luck!

Aug. 5, 2010, 02:19 AM
I just brought my yearling stud colt home from the university after over a week fight with PHF. He was off his feed and called my vet on my way home from work and he was running 105 temp, gave meds and cold hosed him all day then called vet back and took him to university by the time we got there diarrhea had started and he was dehydrated, he was treated at the university for over a week and even had to have several units of plasma. My horses are vacinated for everything water buckets cleaned daily I did however have a dusk to dawn light on my barn so they can see but they are now off. I am watching him and my others like a hawk and am trying to spread the word so others are aware what to look for and seek tx quickly. I am greatful he is alive and as of yet ok except for needing to put some weight back on. I wish there were better vaccines.

Zu Zu
Aug. 5, 2010, 09:36 AM
Bumping for a BUNNY update ~ Jingles that her recovery is progressing uneventfully ~

Aug. 11, 2010, 02:01 AM
wishnwell it is good practice to quarantine horses following a show, travel clinics, etc. in case they picked up some bug, but if it is just PHF your BM is worried about...
PHF isn't contagious from horse to horse.. it is introduced into the horse by accidently ingesting the host.. it is theorized the host may be the May fly, and has also been thought to be linked to freshwater snails...

Aug. 17, 2010, 07:17 PM
I am happy to hear all your stories of successful recovery from PHF. These stories give me great comfort knowing my mare has a great shot at a full recovery.

My mare currently sits in isolation at MAE and today is finally doing better. They suspect she too has PHF (waiting on test results to confirm). Her case started with not eating and a bad battle with colic which precipitated in less than 6hrs to a 105 fever.

My mare is the third horse in less than a year to be diagnosed with it on this farm. This first horse was put down because of founder, the second had a mild case and recovered quickly, and now my mare was knocking at deaths door this past weekend.

I ride with one of the most fabulous riders and she gets along with my mare like no one else and keeps her so perfectly prepared for me. Without her and my vet being as attentive as they are; I am sure my mare would be dead.

I am struggling with taking my mare back to this farm; I have options outside of taking her back there. My insurance has also made it clear PHF will be exclusion on my policy next year.

I guess my question is did you all return your horses to the same farm?
Have there been other cases where you board or on your farms?

Aug. 17, 2010, 07:55 PM
Biggest preventable risk factor is keeping the lights on (turn those lights off, they attract mayflies) at night and access to fresh water streams and ponds. Insist that your boarding facility turn off the lights and fence off water.

Aug. 18, 2010, 10:58 AM
yea, I have to agree Laura. keep the lights off, especially around water troughs and feed buckets.

you can get those yellow lights that dont attract bugs too

my horses live at home with me, so I wont be moving them to another farm, BUT, I have all my big outside lights off at night now except a few we have changed to yellow, and one that is outside the paddock area. there are A LOT less bugs around the night paddock now.

im also continuing to monitor everyone during this time by taking their temps once a week. which may be overkill...... but........ this one scared the crap out of me....

BTW - Bunny is back to normal. full recovery! im still guarded, but, she is fine. THANK YOU EVERYBODY!!!!!

Aug. 19, 2010, 05:28 AM
I am curious as to how/why horses are started on tx for PHF with symptoms of just NQR and a fever. Soooo many things that are not PHF manifest this way. My boy recently had a fever of 103.5, didn't want to eat, depressed, and wouldn't even move. It came on rather suddenly. He was all bright eyed and bushy tailed at dinner time and feeling miserable an hour later.

I called the vet out.. and she took blood, gave him banamine, a sedative, and an antibiotic injection.. and prescribed SMZ's. I came home and read this thread... and was scared he might have PHF. I asked the vet.. and she said 'possible.. but not likely as there are no mayflies in this area'.. to watch for diarrhea or other changes and call her immediately if I saw any. She said treating a horse for PHF without a confirmed diagnosis is like giving chemotherapy to a person that doesn't have cancer. His first bloodwork came back with his lymphocytes a little low. The second bloodwork, two days later came back normal. His fever lasted three days (managed with banamine).. on the third day, he had slight edema on his belly...that went away three days later. He was on SMZ's for 2 weeks....but was feeling better from just the banamine. It would seem, in this case, my vet was right... in this case it was probably erlicchia (sp?)...which is a broad, general term for a tick borne disease...and not PHF. I am thankful she was right.. but am curious what led your vets to just immediately go to treating for PHF with only a fever and NQR as symptoms??... so many things manifest that way...:confused:

Aug. 19, 2010, 09:03 AM
Yes, many things manifest this way...but the consequences of leaving PHF untreated can be dire. In my area, we consider it safest to assume it's PHF, begin treatment, and then if they don't respond in 24-48 hours re-evaluate. I'm glad your horse is doing well!

Oxytetracycline is hardly comparable to chemotherapy, IMO. Yes, all antibiotics may have side effects, but this is a case of "it's better to be safe than sorry." FWIW, we use oxytet for other rickettsial organisms as well, not just PHF.

We've been seeing a particularly nasty strain recently in our area, in which they aren't getting the typical colitis. Rather, they get the fever, and then just founder. So continue to keep an eye out for lethargy and fever!

Aug. 19, 2010, 09:10 AM
She said treating a horse for PHF without a confirmed diagnosis is like giving chemotherapy to a person that doesn't have cancer.

IMO - not true. giving IV antibiotics is not the same as giving chemo. IF Bunny didnt have PHF, this treatment wouldnt have hurt anything.

the problem is, the actual PHF test takes 2-3 days to get back. IF YOU WAIT THAT LONG, it will probably be too late to save your horse.

His first bloodwork came back with his lymphocytes a little low. The second bloodwork, two days later came back normal.

Bunny's CBC came back totally normal. her WBC was normal range, and her liver enzyme was normal range (my vet got those tests back the day she pulled the blood)...... but, 3 days later her PHF test came back positive.

what exactly were they testing for? there is an actual test for PHF.

if they were just doing CBC / "WBC", chances are they would have come back normal. PHF is very stealth. what I understand from what Ive read is, it actually hides in the DNA, until its too late for treatment.

there were a couple of reasons why we treated ASAP before the PHF test came back

1. Bunny was NQR
2. Bunny had a fever
3. its Mayfly season where I live, and my vet already had about 10 confirmed cases in her hospital when I called
4. One of my best friends 4 year old gelding just died a few weeks earlier from PHF. and another friends horse got it and survived a couple years ago.
5. im NOT taking ANY chances with this infection. I will attack it with every thing I have. not willing to lose my girl over "waiting to see" and the treatment wouldnt hurt anything if she didnt have it.

Zu Zu
Aug. 19, 2010, 09:24 AM
So glad to read Bunny is back to normal ~ GREAT ~

Aug. 19, 2010, 10:39 AM
I just went through this with my MFT Blue....

I almost lost him.

It manifested as Blue just being NQR. Diarrhea. Enteritis. And a fever. Thank God for attentive BO's. If we would have waited he would not have made it.

His blood work came back fine. At that point he didnt have diarrhea. Luckily the BO and I were there when he had his first loose stool. Called the vet IMMEDIATELY and drove as fast as I could to the vets office to get his antibiotics.

He didnt eat hardly anything for two weeks. He lost a lot of weight but he is on the road to recovery.

Aug. 19, 2010, 11:43 AM
First thing I do with a high fever is 1) call vet, 2) give Banamine, 3) ice feet until vet comes. Better safe than sorry.

One of ours had a weird illness over the winter. Looked like PHF (but it was winter), with no diarrhea. He was treated with Oxytet. We never did figure out what it was, but he did recover just fine.

Aug. 20, 2010, 12:42 PM
oh, found a pretty good potomac article. if anyone wants to read it.


the only thing it seems to leave out are the laminitc dangers, and what YOU can do for your horse (that is SO important) like ice packing their backs AND all 4 feet. and the use of Banimine is important for fever, and to try to prevent the endotoxins from entering the system.

Oct. 23, 2010, 01:12 PM
I have just been living this nightmare. We lost our best broodmare to PHF on Oct.5 - unfortunately for her PHF is quite rare in our area, in the last 2 years there have been all of 2 cases until my 2 in the last month. And her temperature was 102.4 at its worst, if it had been higher I think he would have started treatment for PHF as he wasn't entirely ruling it out, he just didn't think it was likely. So she was treated for c.difficile which is the most common cause of acute diarrhea in our area, and as she developed the diarrhea on a Saturday the bloodwork did not come back in time. Interestingly, after reading this thread, she did not develop laminitis, her feet were cool right up until the end.
Then on Oct. 10 my 30 yo Morgan started with a bit of cowfloppish stools, kept her in overnight to observe, she had a normal BM in there so turned her out like usual. Luckily for her about an hour later I brought her back in, and she had a watery stool, so I called the vet (bloodwork was back now from first horse) and we immediately started her on tetracycline and banamine. She recovered so fast and so well she never even knew she was sick. Other than being ticked off that she had to stay in with an itchy catheter in her neck.
The first mare was definitely off her grain, but only slightly depressed - nothing you wouldn't expect from a horse with a 102.4 fever. The Saturday AM she was completely her normal self, but had acute diarrhea by Sat. night.
The old girl did not go off her feed, and in hindsight, yes she was a little quieter than usual for a few days before her manure got loose, but she *is* 30. She has days like that.
These two, plus two others who have been symptom free so far were in a field with a pond - which I was only using temporarily as there is some construction going on in the field they are normally kept in. I did use the pond field last year without issues, and the previous owner of the property used it for 20 years as the only source for water for his horses without incidence.
Then last Saturday night my yearling (my nicest horse, and the only child of the mare that died) came in with a fever of 101.8 and a puffy left hind - however this seems to have truly turned out to be an abcess, as it is draining nicely, his fever is gone and the leg is unpuffing. As much as I was tempted to whap him onto the tetracycline just in case, I've also read that you can delay or mask symptoms if you treat pre-emptively. So I am hoping that this is the right decision...It has been weeks since I have felt anything other than exhausted and worried.
So....farm management post-PHF? It's my place, so moving isn't practical, as much as it is tempting...Seeing as COTH is a US board I'm hoping there will be a wealth of experience that we do not have in Central Ontario. I don't need to use the field with the pond, but we do have other areas where we get standing water short-term in the spring. Also the bugs that transmit the infection have wings. We don't have an outdoor light near the barn anyway.
Information about the vaccine is contradictory. Some say don't vaccinate as it may mask and delay symptoms until the disease is far more advanced.
Spray the pond field for arthropods? Except the run-off goes through another field so I am not sure how safe this is?
I am taking everyone's temperatures on alternate days, I have three I do one day, the other two the next.
It really is a nightmare, although I am grateful that it wasn't clostridial as that I think would be worse.