This is an archived Horseadvice.com Discussion. The parent article and menus are available on the navigation menu below:
HorseAdvice.com » Diseases of Horses » Nervous System » Incoordination, Weakness, Spasticity, Tremors » Botulism Poisoning, Shaker Foals »
  Discussion on Botulism, round hay bales, and weather
Author Message

Posted on Saturday, Feb 9, 2002 - 2:27 am:

Dear Dr. O and members:
I would like to share a warning with other horse owners who are experienceing the unseasonably warm and wet weather that is occurring in many areas of the country this winter.

Currently, my 12 year old gelding is recovering from poisoning through ingestion of preformed botulinum toxin. This winter, the boarding barn where he is kept placed round bales in the turn- out paddocks in order to provide the horses with a
constant supply of hay and forage during the time when grazing is minimal to non-existant.

The bales were carefully selected for quality, they had been stored inside and had never been wet. They were purchased from a reputable hay dealer who has provided many tons of excellent hay over the years. Unfortunately, the problem arose after the bales were placed in the paddocks.
We had 2 weeks of alternating warm, then cold, weather, and there were wet rainy days, as well.
Apparently, the bales became wet and this allowed spores to enter their vegetative state, producing toxin that my horse must have ingested.

Fortunately, my wonderful vet suspected botulism (although he had never personally seen a case) and referred us to the Ohio State University's new Gailbreath Equine Center, where an Australian resident confirmed the problem quickly and started him on treatment, including administration of antitoxin. (Apparently, there are many cases of equine botuslim in Australia.) My horse never lost the ability to stand, although his legs were weak and trembly, and he spent a lot of time lying down, and he was able to swallow, but he did lose control/tone to his lips and was unable to prehend food, or form an effective bolus. He was tube fed at the hospital for three weeks.

He has come home now, but while he improves daily, he still can't eat enought to support his nutritional needs. I am currently admistering liquified senior complete diet via nasogastric tube on an every 6 hour schedule. It looks as though it will be several more weeks before he is able to feed himself or drink.

While he was in the hospital, there were 2 more farms that had poisoned horses...on one farm, 5 horses died before the problem was recognized and appropriate help was sought. One horse was only slightly affected, and survived. In every case, the horses had been eating round bales of hay.

The cost of treatment is very high: a single dose of antitoxin runs $2700! Fortunately, my horse has major medical insurance, since his medical costs are at about $6050 now. And they would be a lot worse if I was unable to handle the technical problems of nasogastric intubation and scheduling demands.

Please consider this danger if you are currently feeding round bales, or if you feed ANY hay outdoors in a manner that allows it to become wet
before the horses can eat it all.

This has been a very expensive and labor intensive education for me (although, as my husband pointed out, it has been a real bonding experience for me and my horse!!) and I would hate to have anyone else have to learn this stuff the way I have!

By the way, I cannot tell you how wonderful the vets, students, and nursing staff at OSU have been. My horse received truly excellent care, and everyone was very supportive and compassionate during a very frightening and difficult time.

I hope this story can help to keep other horses safe.

Sincerely,
Anne Breden

Posted on Saturday, Feb 9, 2002 - 8:14 am:

It is wonderful to hear your horse is going to be fine. An excellent post and heads up to the folks.
DrO

Posted on Saturday, Feb 9, 2002 - 9:42 pm:

Dr. O.,

What has been your experience with feeding out round bales to horses? Here in New England, we are leary of feeding them out due to a tragedy involving botulism at a Fjord breeding farm in Massachusetts a few years back. As I understand it, the farm lost five horses; most of the five were expensive broodmares. There may have been other incidences also (would you know of them?). The vets I know here, in Vermont, don't recommend them for horses.

From where does the botulism organism come? Does it only thrive in bales that haven't dried correctly? Is there a way of testing a round bale for botulism? Can you take a core sample or would that not show accurate results? Does botulism ever show up in square bales? Is it reasonable to assume that botulism is just a natural risk of feeding out any kind of hay?

Apparently, feeding out round bales to horses is very common in some parts of the country. Do you feed them to your horses? Would you recommend them to your clients?

Thank you.
Holly Wood

Posted on Sunday, Feb 10, 2002 - 3:52 am:

I am very interested in this post because I have never heard of botulism being a problem in "open" round hay bales. Wrapped bales or haylage or silage, yes, but not ordinary hay bales. Could it be that the hay was out in the warm and wet for a very long time (ie it wasn't being eaten fast enough)?

Great to hear that the horse will be OK though at great expense to owner and bank account...

All the best

Imogen

Posted on Sunday, Feb 10, 2002 - 8:02 am:

I have always worried about the round bales being out in the weather, so what we have been doing is watching the weather forecast and try to put them out when it's going to be dry for at least 5 days. I don't really worry if it just sprinkles on them but when it pours we pick them up and throw them over the fence to our cows. If they are so far gone that we can't pick them up we spread them and put out new bales. I know of several people whose horses have foundered after leaving bales out for weeks at a time. My neice finally, after a foundering episode, built a little hut with a roof for her bale. I also put my bale on 3 old tires to keep it up off the ground.

Posted on Sunday, Feb 10, 2002 - 9:01 am:

Hello Everyone,
Most everyones questions are covered in the article on Botulism associated with this forum. To address the round bale issue specifically, I do not think good quality round bales that are stored correctly represent a larger threat per se but there are two other issues:
1) If is harder to monitor what might be in a round bale.
2) Once set out into the weather they may begin to rot if allowed to get wet.
DrO

Posted on Sunday, Feb 10, 2002 - 10:29 am:

I have always steered clear of round bales because of the above reasons. And when I did have to temporarily board at a stable that fed them, I vaccinated my horse for botulism at their - & my vet's - recommendation.

Now that I have my horses at home, I do put plenty of hay out for them, but flakes which I fluff up into a large pile. Needless to say, by the next morning, this hay is spread out all over the place, much of it thoroughly trampled into the mud making it virtually impossible to rake up. Is this sort of situation a botulism risk as well?

(P.S. Please forgive if this should have been brought up as a "new discussion" - wasn't sure."

Posted on Sunday, Feb 10, 2002 - 3:59 pm:

Thank you, Dr. O.

Apparently, the incidence of botulism in horses is uncommon. Still, to be safe, is there any reliable way of testing a round bale for botulism before it is fed out?

Thanks,
Holly

Posted on Monday, Feb 11, 2002 - 3:38 am:

Simple observation is probably the best check. Though there are tests for the toxin I do not think there is a practical way to check round bales of the nature of the poisoning: it tends to be focused in small areas around "rotton areas" or small mammal carcasses.
DrO

Posted on Monday, Feb 11, 2002 - 4:38 pm:

Thanks, Dr. O.,

I guess that is what I kinda thought, but was hoping there was a way to guarantee the safety of round bales. If the carcasses are totally dry before baling, will that prohibit the growth of the bacteria?

Holly

Posted on Tuesday, Feb 12, 2002 - 7:19 am:

Yes but "that dry" in not probable and the toxin may have already formed.
DrO

Posted on Tuesday, Apr 2, 2002 - 9:22 pm:

Hi, Dr. O. and members:

Just thought I'd give you an update on my botulism
horse's progress, and ask Dr. O. a couple of questions.

As I told you in a previous post, my horse was poisoned with botulism toxin on January 11th. I took him home for nasogastric feeding after 3 weeks in the hospital. Well, it has been almost 3 months now, and while he can use his mouth well enough to eat both pelleted feed and hay, he is still unable to drink on his own. I give him 3 gallons of water by NG tube three times per day.
His lower lip is still pretty loose and floppy, and he isn't able to form a vacuum by pursing his lips. I've seen him try to lap up water, but apparently, this is not really possible for horses. In all other respects, he seems to be fine; he has gained back the weight that he lost initially, he is sleek and shiny, and he goes out in the pasture (by himself) to graze. He runs and plays with the horses over the fence, and seems very cheerful.

When he was first affected, he developed severe bilateral facial paralysis. The nerves most affected appeared to be the motor branches of the trigeminal nerve (CN5), the facial nerve (CN7), the glossopharyngeal nerve (CN9), and the hypoglossal nerve (CN 12). These were quite equally affected on each side of the head. Function has been returning very slowly over the last 3 months, again, pretty much bilaterally, although now there is a noticeably greater improvement on the left side compared to the right.

So here is my question: the folks at OSU said that such serious and lasting facial paralysis is very unusual, in fact, unreported, in botulism horses. (They are still sure that his problem was and is botulism toxicity but they are trying to find other explanations for the face and mouth problem. ) They have ruled out things like EPM.
They have even mentioned something like idiopathic facial paralysis that has been reported in dogs. (But doesn't that only affect CN7?) Have you ever seen anything similar, Dr. O.?

Personally, I don't see a contradiction here, since it is known that botulism toxin has an affinity for cranial nerves, especially initially. I guess the thing that bothers me is the time it is taking for him to recover. Is this an unusually long time to regain nerve activity? I am concerned that if he still can't drink when warm weather arrives, it will be a lot harder to meet his H2O needs. Do you think that the 9 gallons he gets now is excessive, or inadequate, or just right? (I feel like Goldilocks.) His appetite, manure, and urination seem fine (maybe a bit heavy in the urine department.)

Another horse that was hospitalized the same week has recovered very well; she could eat but could not stand without assistance for 6 weeks or so. In fact, she went home with a sling. However, I am told that she is out of the sling and doing great.

At some point, the doctor at OSU told me the rate at which damaged nerves recover, but I didn't write it down. Would you happen to know
the millimeters per day, or whatever, Dr. O.?

Thanks for listening--
Anne

Posted on Wednesday, Apr 3, 2002 - 8:13 am:

Thank you Anne for taking the time to update us. I have never had a case of botulism in our area so my postings are all from my research.

Botulinum, the toxin responsible for the disease, does not kill the body of the nerve so the rate of regeneration (1 mm a day) is not really relevant. It disables the motor nerve's end plate so that acetylcholine cannot be released. It requires regeneration of just the endplate and this is usually accomplished in a week to 2 weeks though occassionally longer.

Six weeks is longer than any cases I can find documented in the literature. 3 months is quite odd and the first thing that occurs is the possibility of on-going intoxication. Has this been looked into? Possibly the bowel is the source?

I think it is important to keep an open mind for the possiblity of other disease, but there are not many diseases that really look like botulism. Extreme electrolyte imbalances and organophosphate poisoning are the only thing that comes to mind readily but even with these there are important easily seen differences.

As you study the literature it is apparent that researchers are still fleshing out the various toxins and their effects from the many strains that are already identified. Perhaps we are looking at a strain that is more toxic? Importantly is that your horse continues to improve and there is no reason to suspect this will not continue until he is 100%.

Keep us updated next year it may be someone else worried about the time and take comfort knowing they are not the only ones.
DrO

Posted on Monday, Apr 22, 2002 - 4:16 pm:

Hello everyone, sorry to barge in this thread, but I do have a question that may be relevant.

A friend's otherwise healthy gelding is showing symptoms of botulism (suspected only) while awaiting results from a EMND sample testing. So far he does not have any facial paralysis. his symptoms began in the hind end, and have suddenly progressed to his front end. He is upright, but unwilling to move forward. Additionally his eyes are dialated.

Any thought as to whether this might actually be botulism? The only other fact I know for sure, is that his liver enzyme test showed something called "AST" completely off the chart.

Thanks for any imput whatsoever.

Posted on Monday, Apr 22, 2002 - 11:44 pm:

Hi, Tiani:
I'm sorry to hear about your friend's gelding. The problem with botulism, and with EMND, is that there are no readily available, definitive tests available for these disease processes. Veterinarians usually must rely on history and clinical signs to arrive at a diagnosis. Dr. O. will be able to tell you more here, and will be able to give you some input on the significance of the elevated AST levels, but from my experience, I can tell you that if it is botulism, the sooner you can get on treatment, the better for the horse. Prognosis in treating a horse that is still able to stand is much better than in treating a horse that has become recumbent.

Botulism horses often show weakness and trembling in affected limbs, but they are not truly ataxic, although they may appear to be due to weakness.
I sort of thought that botulism was something that began in the front end of the horse and worked its way back, but I also know that there are very few "typical" cases! Dilated pupils have been reported, and symptoms can take several days to develop after exposure to the toxin. How long has the horse been affected?

Are there any aspects of his care and husbandry that could support either diagnosis? EMND horses often have not had access to pasture, fresh grass, quality hay, etc., for extended periods. Botulism could be associated with ingestion of contaminated feed (often hay) under conditions that favor vegetative growth of the ubiquitous botulism spores--things like high (alkaline) pH,
warm temperatures, moisture, or the presence of a dead animal. Or there are (much more rarely) cases of wound botulism, where the organism is multiplying within injured tissues.

I hope that your vet is able to discover the true problem soon, so that the horse can be treated appropriately. I'll be interested to read Dr. O's thoughts here; and I hope you will keep us posted as to horse's ultimate diagnosis, treatment, and progress.

Since I am back in this discussion, (botulism), I'd like to give you all an update on my own botulism victim: He has regained the ability to drink on his own!! This occurred three months to the day of his initial illness. His formerly loose and floppy lips are almost completely normal now, and you have to look closely to see any problem at all. I haven't had to give him any water by tube for a week, and he is doing great, so I think we have really and truly licked this problem once and for all. I can't begin to tell you how relieved I am, or how grateful I am to all the veterinary personnel who helped us through all our questions and obstacles.

Tiani, if this horse does turn out to have botulism, don't despair! It requires intensive nursing for an extended period in some cases, but it is do-able. If there is any nursing info that I can share with you, please let me know and I will be happy to help in any way I can, through correspondence on this site, or privately.

Posted on Tuesday, Apr 23, 2002 - 8:09 am:

Delighted to hear about your horse Anne. After our last posts I did some further studying and the more I looked the more convinced I became that your horse had some ongoing low grade exposure to the toxin, probably in the bowel.

Tiana, there is little for us to say with the brief second hand description other than the clinical symptoms seem consistant with botulism but there is not enough to say that other diseases are not possible.

I do not think mydriasis (dilated pupils) is consistant with EMND.

Though you might see mild elevations in the AST, the very high AST levels are not consistant with either disease, in the standing animal, and are nonspecific for liver and muscle diseases and may be indicating some other problem, particularly other toxins.
DrO

Posted on Wednesday, Aug 14, 2002 - 3:59 pm:

Update on my previous post. The gelding in question was indeed suffering from botulism, as well as vitamin e deficiency (malabsorption, I suppose that would be?) He spent three weeks at the clinic and luckily never progressed to facial paralysis. Eventually the suspecvt cause was nailed down to a very tiny wound on the horses' neck, which to this day (months later) remains noticeable. This very ill horse was expected to die but he exhibited a strong will to live and has managed so far.

The basic problems remaining are intertwined. He shows little strength in hind hindquarters, which have a very wasted appearance visually (altho he condition scores via Henneke at about 4.5). He is unsteady and consequently getting his feet trimmed has turned out to be nearly impossible. Naturally his hooves are horribly overgrown and I have helped the owner try a number of unsuccessful methods to get him to lean so his feet and be trimmed-a large part of being uncomfortable I am sure. Some of this may be due to the vitamin e deficiency also. The second problem is the horses' apparant inability to gain significant weight. Each time the owner attempts to pump the ration up to provide the protien needed to replace lost muscle mass, the horse experiences diarrhea. Right now he is on free choice grass hay and the amount of concentrates his system seems to tolerate. I have suggested a number of other approaches but the owner is unwilling to change anything at this point (such as additional feedings, a very small amount of exercise, a nutrient buffer, higher quality grani products, etc) but I gut feeling is that this horse will waste away until our winter does him in-which is due in about six to eight weeks.

And thoughts as to how I can help this horse recover?

Posted on Thursday, Aug 15, 2002 - 6:33 am:

Hello Tiana,
Since the horse owner is resistant to change anything Tiana, I am not sure what we can do. The problem sounds more like EMD than botulism you might review it, Equine Diseases: Nervous System: Equine Motor Neuron Disease (EMND), for other suggestions.
DrO
I will move these posts out of Annes discussion in the next few days and into their own.
Home Page | Top of Page | Join Us!
Horseadvice.com is a BBB Accredited Business. Click for the BBB Business Review of this Horse Training in Stokesdale NC