Just posting this to see if anyone else has had similar experiences with their horses…
My mare has since died, but we were never able to figure out what was wrong with her. So I’m left wondering if anyone has had a similar experience with their horse.
Horse in question was a 16 year old thoroughbred mare. She was otherwise healthy, albeit thin from the winter and had extreme pickiness with grain. She was being treated for ulcers when she got sick, but had no other health concerns. She had been dewormed and was UTD on all of her vaccines.
This all started on April 7th. First symptom I noticed was her nose was stuck to the side. Nothing else. She had her feet done that day and was fine other than her nose. The next day, she was unsteady, not crazy but definitely noticeable. I called the vet out and she said it probably wasn’t botulism, perhaps EPM. She gave me Marquis to try while we waited for the EPM test to come back. She continued to get worse and the EPM test came back negative. We kept her on Marquis and started her on IV tetracycline, steroids, decoquinate, levamisole, vitamin E, and banamine. We also ran more bloodwork. We even tried acupuncture on her face to help with her facial paralysis but it didn’t work. Despite medications, she continued to decline. Her neurologic symptoms worsened daily, she went blind in the side her face was paralyzed on (she couldn’t move that ear very well either), she lost the ability to eat and rapidly lost weight (she could pick up food and chew it but couldn’t physically swallow so she would spit everything out. Grass, chaff, mash, grain soup, everything). We did a nasal scope and everything was clear. Her bloodwork came back and everything we tested for was negative (we tested for EPM again, Lyme, anaplasmosis, and WNV. All negative). I finally decided to euthanize her on April 19th as nothing was working and she would have to be tube fed every day and I didn’t want to put her through that.
To add, she didn’t have a fever any time we checked, no signs of trauma of any sort, no swelling, no bleeding. Nothing. She was fine one day and then dead less than 2 weeks later. No other horses at the farm had any symptoms either. Anyone have any ideas of what it might’ve been?
I’m so sorry this happened. How awful for you and for her. I don’t have any answers. My one question would be about the tests that were run especially for WNV. Were the tests looking for antibodies to the virus, or for the virus itself? With this rapid an onset, antibodies might not have been formed.
Actually, a couple of other questions come to mind. What part of the country are you in, and which of the encephalitises was she vaccinated for? Was she vaccinated for rabies and tetanus? Did your vet do a necropsy on her?
The rapid onset and progression of symptoms make me think toxin, tumor or virulent infection, but I’m sure your vet was thinking the same things.
Was Botulism ruled out? Botulism causes an inability to swallow.
I’m so sorry you went through this! Nothing to add just sad for you.
Was a necropsy done?
Maybe tumor
Stroke
Blunt force trauma causing fracture with nerve damage
Vet didn’t think it was botulism as her tongue tone was “unremarkable” or something like that
We tested IgG and IgM for WNV. IgG came back positive, though my vet said that was because she had received the vaccine. IgM was negative.
We are in Northern Virginia. She was vaccinated for Rabies, Eastern Equine Encephalomyelits, Western Equine Encephalomyelitis, Tetanus, West Nile Virus, and Potomac horse fever. I didn’t get a necropsy though I really wish I had. I just couldn’t afford the extra $500 it would’ve been after the multi thousand dollar vet bill I had to pay 
Honestly, my vet has no idea what it could’ve been. She didn’t think trauma as she had no signs of it, didn’t think tumor because there would’ve been symptoms leading up to it, wasn’t sold on toxin as not a single other horse on the property had any issues. But oddly enough, I’m not sure if you’ve heard of the Gentle Giants draft rescue in Maryland, which is like an hour from where I board, but they had a horse named Jedi who crazy enough had the same symptoms as my mare. They brought him to Virginia Tech and even all of the vets there had no idea what it was. They did do a necropsy, but I don’t think they ever said what it was. I messaged them but I haven’t heard anything yet.
I was thinking maybe it was a stroke. Vet didn’t think it was trauma because there wasn’t a single mark on her anywhere. She wasn’t tender anywhere either. Vet didn’t think tumor either as she never had any symptoms leading up to it. I thought maybe it was a snake bite, but she had no swelling anywhere which would’ve been present if it was a snake. There were no poisonous plants in her field, we checked. Vet didn’t think botulism either because she didnt have the right markers for it.
Thank you for your thorough reply. Weird that there was another horse with the same symptoms. Did both cases happen around the same time?
I’m sorry you lost your horse, especially in such a way. It’s so heartbreaking to watch them continue to decline despite our best efforts.
It sounds like your vet was very thorough. Although horses aren’t humans, I sometimes think, “Well, if these symptoms were in a person…”
Since pretty much everything else was ruled out, I would guess it was a stroke or a tumor that had finally reached a size that began to cause symptoms.
OP - Sounds like damage to cranial nerves. Either trauma or disease. I lost a horse to polyneuritis equi. His problems were noticeable on right side of face, eye sunken in socket, rotated inward, little/no response to sudden hand movements around that eye. Trouble chewing, trouble getting tongue back in if it was pulled out the other side. Began to lose feeling in right ear, and then a ways down that side of neck. It also impacted his hind end, mostly evident in neuro tests. Did every test on planet, xray showed no cranial trauma, MRI showed nerve damage. Necropsy conclusion indicated the polyneuritis. It is basically done via process of elimination. His decline was also fast. It is believed to be auto immune related but not certain.
https://en.wikivet.net/Polyneuritis_Equi
My sympathies.
Edited to add: the description reads that it is more hind end, but vets at Univ Fla, said that is not always the case
I do know someone in Virginia that had a horse diagnosed with botulism. He had partial facial paralysis, but thankfully never went down. He went home after treatment at Morven.
That sounds like Temporohyoid Osteoarthropathy (THO). So I have the thread going for the mare at UC Davis with the vaccine reaction. She had THO in 2020 because, of course, she did.
Nose to the side. Ear and eye went offline. Facial paralysis like Bells Palsey.
I took her to UCD, and they diagnosed the THO with a guttural pouch endoscopy. However, it does sound like you scoped for that, so maybe not.
It took a year for all the nerves to come back online. Luckily, she was not so bad that there were any neuro symptoms. I had her on the table within 7 days of showing signs of the problem. She had the surgery for it and came back like a champ.
I’m really, really sorry you went through that.
@avosstb Was she tested for Leptospirosis? that can cause uveitis/moon blindness and a general decline overall including organ failure (kidneys) other thing that comes to mind would be EDM which is a neuro degenerative disease that attacks the brain …that can only be tested post mortem/necropsy but they can deteriorate quickly …or wobblers -that would be checked via myelogram …the EPM & Lyme could truly get verified if spinal tap was done and spinal fluid tested vs just checking blood.
