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  Discussion on Equine herpes aftermath and recovery
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New Member:
Kayfry

Posted on Wednesday, Mar 12, 2003 - 3:44 pm:

I have a homebred Thoroughbred/Appaloosa gelding, turning 4 in May. As a yearling, this horse experienced a severe neurologic illness that we presumed was caused by herpes, although repeated tests for the virus (blood tests and nasal swabs) over a period of several weeks came back negative. He also tested negative for West Nile virus and equine infectious anemia, has always been current on all his vaccinations, and we eventually dismissed the possibility of EPM because of the course his illness followed. My vet considered the possibility of head trauma, but there was no evidence of this, and it seems to me the fever and other signs, plus his white count at the time, argues for a viral cause. Brief history of the illness is as follows: he had been completely well until the week before his first neurologic signs; during that week he ran a slight fever and his hind ankles swelled. We were treating for simple scratches, but the swelling spread to his front legs, then up all four legs, eventually all the way up his belly - most of his body was blown up like a balloon at that point. He kept a good appetite this whole time, and seemed otherwise normal. My vet was treating with antibiotics, waiting for blood tests, when the horse suddenly became severely ataxic one day. His tail was also flaccid and he dribbled his urine, had great difficulty walking, but never did go down in his stall. Despite not having a definitive diagnosis, my vet treated the colt aggressively (antibiotics, steroids, anti-inflammatories, I.V. DMSO), and we provided good supportive care. I decided against subjecting him to the 2-hour-plus trip to the University of Pennsylvania, New Bolton Center, for further diagnosis and treatment (because I felt it wouldn't change his outcome, since we were doing everything they would do there), but my vet was in constant contact with a specialist at New Bolton Center, who agreed that it sounded like herpes infection. But since we never had a spinal tap done, we have no way to know for sure. How he may have been infected is also a mystery, because the only other horses he had been in contact with were his 2 pasture-mates - my old Shetland pony and another old gelding who had been his companion from the time he was weaned at 7 months - and neither of these guys showed any symptoms. I could only assume one of the old guys was a carrier who for some reason was shedding virus without having any symptoms(?) Fortunately, my colt's acute symptoms improved fairly rapidly, and within a few days it was clear that he would pull through - although the neurologic deficit resolved very gradually over many weeks and months. At first, it appeared he was completely deaf, but about a year later it became apparent that his hearing was returning to normal. Long before that he appeared to regain normal coordination, and now, almost 3 years later, the only obvious reminder of his illness is a slight head tilt (to the left). He has been in training for an eventual career as a show hunter for about a year, and has normal gaits and plenty of jumping ability, as far as we can tell. But here is my question (finally): This horse is very quiet, even lazy, and despite being half Thoroughbred, is not a very forward-going horse by nature. He seems to have very little energy and tires easily - maybe just due to his greenness, but I don't know. He is also stiff to the right, which I know is normal for lots of horses, but his left-tilt does seem to make this right-sided stiffness more pronounced. He will take either canter lead, but definitely prefers his left. My trainer thinks he is a little weak on his right side, and I wonder if this is just a normal part of his development as a greenie, or a subtle deficit from his serious neurolgic illness as a baby? Will training and conditioning that improves his overall strength and flexibility likely compensate for this, if it is a result of his illness? Does anyone have any experience with the long-term effects of equine herpes infection (or neurologic disease in general)? Any thoughts or suggestions, Dr. O? Thanks in advance to anyone with any experience with this.
Moderator:
DrO

Posted on Wednesday, Mar 12, 2003 - 6:55 pm:

Where was the horse located when this occured and what was the time of the year?
DrO
Member:
Kayfry

Posted on Wednesday, Mar 12, 2003 - 8:51 pm:

He was located on my farm in south-central Pennsylvania, and it occured in mid-July. It was in 2000, when he was 14 months old. Actually, I consulted you on this colt at the time, and you were very helpful in clarifying some things about herpes - don't know if you remember this. I understood from various sources that neurologic improvement could continue for at least a year after the initial symptoms, but at this point I imagine that is complete, or as good as it will be - which is actually very good, with the only problems being the ones I mentioned above.
Moderator:
DrO

Posted on Thursday, Mar 13, 2003 - 7:25 am:

Is there a reason to rule out eastern or western encephalitis other than had been vaccinated for these? What was the last time vaccinated vs the time of infection?

I think you know that from the comfort of my desk I cannot differentiate training vs subtle remaining neurological deficits. Yes continued training will make your horse stronger and more coordinated, but will he will ever be competing successfully at level you desire, only the future knows.
DrO
Member:
Kayfry

Posted on Thursday, Mar 13, 2003 - 11:38 am:

Well, I guess the only reason to rule out eastern or western encephalitis WAS that he had been vaccinated - I believe the time of vaccination was either April or May preceding the July onset of his illness - more likely May, about 2 months prior, because we gelded him in April and may have held off on some of the vaccinations. I was under the impression that this vaccine (Eastern/Western) had a very high (close to 100 percent?)rate of protection - is that not true, in your experience? Of course, I know you don't have a crystal ball, but I was just wondering if you (or other people) may have had a similar experience with other horses that might shed a little light on my horse's situation. Thanks.
Moderator:
DrO

Posted on Thursday, Mar 13, 2003 - 6:43 pm:

I have never had a enecephalitis vaccine break through but our incidence here is low enough that it may not be meaningful. You are right the vaccine is considered very good for 6 to 12 months but as you write: near 100% is not the same as perfect and no vaccine is perfect. All things considered I think EEE is likely with all the negative tests for other likely diseases.
DrO
Member:
Kayfry

Posted on Friday, Mar 14, 2003 - 12:05 am:

Hmmm. Well, that's interesting. I've just read your article on EEE, though, and I can't quite see how that fits. Not just because he was fully vaccinated - although for this reason alone it seems quite unlikely - but also because of the outcome. His initial recovery was rapid enough to surprise my vet, who had thought,early on, that he'd have to euthanize the colt. He does not appear to have any obvious brain damage or coordination problems - just the slight head tilt. Any other "symptoms" could just as well be normal for a lazy, laid-back 3-year-old who is still gangly and under-developed - at least, that's what my trainer thinks. It's a mystery, for sure, though, what caused his yearling illness, and I'll mention this possibility to my local vets and see what they make of it. Whatever caused the illness, he survived it and my concern now is his future prospects.
Moderator:
DrO

Posted on Friday, Mar 14, 2003 - 4:58 am:

The outcome would have been effected by the vaccination, though protection was not complete, without it the disease may have been a lot worse. You have ended up with permanant brain damage represented by the head tilt (8th cranial nerve). Good luck with the future let us know how it all works out.
DrO
Member:
Kayfry

Posted on Friday, Mar 14, 2003 - 10:04 am:

True, the head tilt is permanent brain damage, but I see none of the other deficits described in the articles in horses that survive EEE - dullness, difficulty learning, etc. Also, I'm not seeing anything in these articles about properly vaccinated horses becoming infected with EEE (whereas there IS no vaccine that protects against neurological herpes infection) - Why would his protection have been incomplete? Are there other references you could give me? Would there be any way to confirm that this horse had been infected with EEE? I don't think this was ever considered by my vets. At the time, I did a lot of research on equine herpes, because his symptoms seemed so consistent with that virus (I'm a writer and do a lot of research for my work, so I'm fairly persistent at finding information), and I did read that the herpes virus will not always show up in blood tests and nasal swab cultures - that definitive diagnosis is by spinal fluid analysis, which we did not do. I know that herpes infection seems unlikely, too (with the negative test results we got), but to me (and I'm not a vet, of course), it seems as likely as the idea that he was infected with EEE although fully vaccinated, and then recovered with nothing more than a mild head tilt? My own vet actually favored the theory that he suffered both a traumatic head injury and a mild febrile illness coincidentally at the same time - which seems real unlikely to me. Again, thanks for your input, though. That wasn't the answer I was expecting. Whatever it was, I consider this baby's near-total recovery to be something of a miracle.
Moderator:
DrO

Posted on Friday, Mar 14, 2003 - 6:51 pm:

Kay you say in your first post, "This horse is very quiet, even lazy, and despite being half Thoroughbred, is not a very forward-going horse by nature. He seems to have very little energy and tires easily - maybe just due to his greenness, but I don't know." Now in this post you say you do not see dullness?

While herpes is hard to stop it is easily diagnosed and you state in your first post despite repeated attempts it continued to be negative, I would reject herpes based on this.

The 3rd paragraph of our article on vaccines starts: "These factors vary widely from vaccine to vaccine and some of today's commonly used vaccines suffer from poor to moderate efficacy with high reaction rates". Why incomplete (?) could be answered with dozens of reasons with the most common being we frequently do not know why individuals react differently and some do not react completely, to the same vaccines: but it is a very well recognised event with most of the equine vaccines we have. Rabies in thought to be about 80% effective, WNV 90%, injectable strangles 60%, injectable respiratory viral vaccines less than 50%, do I need to go on? Vaccine break throughs happen often enough that they are not considered reportable. Though NO vaccine, human or otherwise, is ever thought to be 100% effective tetanus is very reliable.

I think your vets theory is plausible but I know of no reason to throw out the one I put forth. If you want to start saying some of the coincidental signs were not related, it gets harder and harder to conjecture a possible cause. It sort of is the Occam's Razor of diagnostic medicine: usually the best diagnosis is one that accounts for all the facts.
DrO
Member:
Kayfry

Posted on Friday, Mar 14, 2003 - 11:10 pm:

Okay, thanks very much for your input, again. You've been very generous with free advice. As I said, we'll never know at this point what he had, and as YOU said, time will tell how well he does. I think he's basically fine and I was being paranoid in asking for anyone to predict his future, based on his confusing medical history. If he had never been sick, I think anyone who saw him today would consider him 100 percent normal except for the head tilt (which people seem to think gives him "character.") I can live with that.
New Member:
Bully

Posted on Saturday, Oct 25, 2003 - 2:19 am:

My 3 y/o Qtr Horse gelding was vaccinated for West Nile 10/15 Wed., along w/ my other 5 horses, by Fri. he had swollen back legs & was not feeling well. This horse was the only one that was handled by the Vet, he checked his teeth. Sat. all his legs were swollen & had a 104 temp. We do not have a horse vet in this area, but I called the one I use 2 hours away, and she recommended 2 gr bute, 2xday. By Sunday he was more swollen & his temp was still 104, & he had massive blisters in his mouth. On Monday his glands were swollen in his throat latch area, and he went off feed, his mouth was red & raw.
The Vet recomended Penicillin. I could not find any so I called the local small animal Vet, he used to treat horses but is to busy now, and he could not come, but did get my horse on Excenel 20cc 1xday, we (the 2 vets, & myself) thought he had strangles. So on Monday he was real sick, & I gave him the Excenel & by Tuesday he was better, and Wed he was eating & drinking again. Thur I only gave him 2gr bute once, because I thought he was doing so well. Now it is Friday-his hind end is paralyzed, he can stand, but cannot walk. I know you cannot answer soon, but what can I do to find out what is wrong?????
Member:
Kayfry

Posted on Saturday, Oct 25, 2003 - 9:35 am:

I'm so sorry to hear about your young horse's illness. I'm no vet, so maybe Dr. O. can offer more, but I'd say the most important thing is to get a good equine vet involved with your horse's treatment immediately. The horse I was writing about above, who developed symptoms suddenly as a yearling, is now 4 and doing pretty well, with almost no residual effects of his still-undiagnosed neurologic illness of over 3 years ago (he still has a very slight head tilt which does not affect his performance in any way), I am fortunate to have excellent equine vets in my area, and I'm sure the supportive treatment my vets gave my horse during his illness saved his life. Since we didn't know at the time what the cause of his symptoms was, he was given just about everything to reduce the swelling and inflammation in his nervous system as well as treat other symptoms - steroids, non-steroidal anti-inflammatories, antibiotics, bute and/or banamine, plus IV fluids and DMSO. He was also able to stand but could not walk without falling or nearly so, was very ataxic. Because we live over 2 hours away from the nearest big equine hospital at New Bolton Center of the U. of PA, and because my local vet was in contact with a specialist there about my colt and we were doing pretty much everything that could be done for him at home, I decided not to subject him to the long, difficult trip to New Bolton - if we'd taken him there, it's possible we might have gotten a diffinitive diagnosis with a spinal tap or something. My horses, including this one, have all been getting the W. Nile vaccine for the last couple of years with no problems; I wonder if there are any reports of reactions like the one you describe? Although my horse recovered and is doing pretty well in training, he does seem to have some degree of dysfunction, possibly, of his immune system. He seems to have a consistently low white blood count, for example, and has also seemed to develop respiratory allergies the last two summers, beginning with a cold-like illness that we've had to treat with antibiotics. I really hope your horse pulls through - would you be able to transport him to the vet 2 hours away, or could the vet come to you?
Moderator:
DrO

Posted on Saturday, Oct 25, 2003 - 10:49 am:

Hello Mary,
Someone needs to examine your horse right away to determine what is going on as it is not clear from your posts what may be happening. Did you give any of the antibiotic injections in the hind limbs? They can be quite irritating and if this is the problem bute is helpful, but you must get someone out to look at this horse today.
DrO
Member:
Bully

Posted on Saturday, Oct 25, 2003 - 2:16 pm:

Dr O, Thx so much, for your reply. I have been desperately trying to get a Vet here, all week. I am waiting to here from one now, to see if I can draw blood,and take it to her. I think the Vet that administered the West Nile Vaccine on the 15th should be concerned, but he has not returned my calls. He is also 2 hours away. I gave my horse Banamine this morning, he is eating,drinking,urinating,bowels are moving,he can move his tail, but he is still swollen all 4 legs, worse in the hind legs, and has difficulty walking and moving in the hind end. Thank You, Mary E.
Member:
Bully

Posted on Saturday, Oct 25, 2003 - 2:52 pm:

Kay, Thx for your reply & concern. I am a new member, & I posted onto your discussion, but I am grateful for the concern.
I am desperate that is why I posted yesterday. I have been trying to get a Vet to come out all week.
We do not have a Horse Vet in our area, the one I use is 2 hours away, and did not want me to transport because he is so sick, & she does not have a facility, I meet her at a riding facility where there are other horses.
The good Horse Clinic is 3 hours away.
The Vet that administered the Vaccines, comes here once a month, he has not followed up since I told him the horse started getting sick 2 days after he
vaccinated him. I called him yesterday with the onset of the hind end becoming stiff, and have not had a call back. My colt was the only one he handled, and he is the one sick, all the others are still OK.
Again, Thank you for your concern, Mary E.
Moderator:
DrO

Posted on Sunday, Oct 26, 2003 - 7:51 am:

I would say that continued NSAID's (bute or Banamine) is important but do it under the supervision of a veterinarian. Of paramount importance is that hydration remains good so the drugs do not adversely effect the kidneys.

Important questions are:
  • Was this an infection (viral arteritis?) or vaccine reaction (purpura?). The mouth lesions suggest an infection as they are not reported with purpura.
  • Is the problem with the back end related to the nervous system or response to pain.

DrO
Member:
Bully

Posted on Tuesday, Nov 4, 2003 - 12:31 am:

DrO, Thank You for your quick response, and for clarifying the important questions.
I did talk to my Vet on Oct 26, & she felt it was going into laminitis.
So last Sunday Oct 26, I went back to giving him 2 gr 2xday of bute. I was in the process of trying to get blood drawn to be sent off, and then the fires here basically shut everything down, I had no contact with my vets, they were evacuated, the phones were down, etc.
We were OK, & I just kept doctoring my horse, I did start him on herbs formulated for Kidney, Laminitus & the immune system.
Now- He is still swollen in his lower legs, the skin behind the pasterns split, so I am doctoring that, he is very sore in his hind feet. He tries to walk on his toes, his front feet are sore also, but the back are very bad. His legs are not hot. Is it to late to do blood work, and should he be transported yet?
I thought if he could get a little better I would take him to the good Horse Clinic 3 hrs away, & they could do blood work, & x-ray him.
Thank You, Mary Ellen
Moderator:
DrO

Posted on Tuesday, Nov 4, 2003 - 7:03 am:

I would stop the herbs as there are none that I know of that have any research on them for this use for efficacy and perhaps more important toxicity.

I hate to transport a horse with active founder but considering all the other problems, if this is the only way to get professional care this may be best. But this decision has to be made by someone who can actually examine the horse. Transport the horse free in a stock type trailer or two horse with the divider removed and go easy would be my recommendation. He may decide to lie down while traveling and that would be OK.
DrO
Member:
Bully

Posted on Thursday, Nov 6, 2003 - 1:32 pm:

DrO, Good news! After talking w/ the Vet yesterday,she suggested an ointment mix for the splits & wrap them. He is walking almost normally today w/ his wraps on. The Vet is going to come here next week to see him.
I will give her the herb formulations to check on them. She knows what I am giving him, I have used these for many years, and I should of been boosting my colts immune before he was vaccinated.
I have heard about so many sick horses from the West Nile Vaccine since my horse got sick. I hope
after he gets his blood work done, we might know something.
I will keep you updated. Thank You, Mary Ellen
Moderator:
DrO

Posted on Thursday, Nov 6, 2003 - 6:25 pm:

Glad to hear the horse is feeling better. We have all heard the second hand accounts on these WNV vaccine reactions but after having given thousands of doses (primary, secondary booster, and annual booster) myself, we have not had a single remarkable reaction to this vaccine.
DrO
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