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  Discussion on Mercury detected in urinalysis...
Author Message
Member:
Heidih

Posted on Tuesday, May 16, 2006 - 11:12 pm:

Hi Dr. O,

I'm working with a horse that has been having some strange symptoms. He has gotten nervous and twitchy. He can't stand to be touched and will literally come unglued if a lead rope is thrown over his back. This is from a previously bomb proof horse.

His symptoms started about 3 weeks ago. We had the vet out and without scoping, he was diagnosed with suspected ulcers and placed on an herbal ulcer remedy containing pectin (hence my earlier search for lecithin). The vet also asked for a urine sample.

The vet called today and left a message that the urinalysis showed elevated levels of Mercury. I haven't spoken to the vet yet, I got home after she left for the day, but I'll try to get the exact results tomorrow. This was totally unexpected. He is on free choice grass hay and gets 1/2 lb stabilized rice bran and 1 scoop Platinum Performance, twice a day. He has free choice access to water and a white salt block.

We can't see anywhere Mercury could come from. I have some questions.

1. I searched your site and didn't see any symptoms listed for Mercury toxicity, do you know what the symptoms might be?

2. The horse lives in the middle of a plant nursery, surrounded by young trees. Is there any chance that something they are applying to the trees could contain Mercury?

3. Is high Mercury in the urine something that you've ever seen before? Is there a traditional treatment for it? The vet we're using works with a lot of natural/homeopathic treatments, so I'm not sure if she'll recommend traditional treatments or will go with something homeopathic. I have my doubts about some of the homeopathic items she prescribes, but she also uses a fair share of traditional treatments, so I've stuck with her.

Thanks for anything you can add.
Member:
Suzeb

Posted on Wednesday, May 17, 2006 - 12:03 am:

Hello Heidi,

You could maybe look to the water supply for potential toxicity.
Member:
Christos

Posted on Wednesday, May 17, 2006 - 1:26 am:

Susan is correct, analysing the water is a good idea. Is mercury a known problem in your area?
I would immediately discontinue any grain until it is analysed. Sometimes they're treated with fungicidals that contain mercury.
Are you heating with gas? Leaking gas system is a good source of mercury.
Has the horse received any medication recently?
Until DrO replies:
Mercury poisoning gives neurological symptoms. General ataxia, numbness of the extremities, disturbed vision. The kidneys will have a hard time with mercury as well.
I have heard that vitamin C may help, but let DrO comment on this before you administer anything.
Member:
Christos

Posted on Wednesday, May 17, 2006 - 2:02 am:

Heidi, you may also want to lead him over closely placed ground poles. Not bright ones, let them be difficult to see.
That way you check if he can easily see them and also if there is anything abnormal with his balance or coordination.
The problem you're dealing with may be just poor eyesight or farsightedness or some other neurological disorder irrelevant to a slight increase of mercury in the urine.
Moderator:
DrO

Posted on Wednesday, May 17, 2006 - 7:44 am:

Hello Heidi,
I have not seen a mercury poisoning in horses but they are occasionally reported. However I do not find cases where environmental contamination has caused it nor any chronic cases which may present differently. The use of mercury containing blisters is the usual cause in horses and acute kidney failure occurs. Hmmmm, I guess I am skeptical this is the cause of your problem:
  • Are there other horses on the same farm with problems?
  • What were the levels of mercury in the urine?
In other species more chronic ingestion is similar to what Christos (welcome back!) posts above: peripheral sensory loss, motor difficulties, and visual and auditory impairment. This would typically be a dull incoordinated horse. A thorough neurological exam should be conducted. Though I am uncertain we are not dealing with a primary behavioral problem, sometimes things happen to horses that completely change their personalities but no disease process can be found, horses that present with hyperesthesia without fever should have the following diseases considered:
  • painful skin diseases (should not be other neurological signs)
  • Tetanus
  • West Nile Virus
  • fumonisin (moldy corn poisoning)
  • Equine motor neuron disease
  • Rabies (would not have survived 3 weeks)
  • Swainsona poisoning (plant in Australia)
  • Astragalus and Oxytropis poisoning (plant in North America)
As to what the horse might be exposed to from the tree farm, best is to check with them to see what is being used that might migrate to your farm.
DrO
Member:
Heidih

Posted on Wednesday, May 17, 2006 - 10:32 am:

Thanks for the replies everyone.

I guess I was taken a bit by surprise with the message I got last night. Poisoning never entered anyone's mind with this gelding. We were hoping it was discomfort due to ulcers and that he would heal. After thinking about it last night, Mercury poisoning seemed a bit strange. None of the other 12 horses on the farm are affected, although Macho gets his own separate hay and grain. He's very allergic to Alfalfa and to Oats. If he gets any of either he immediately starts to cough and gets a terribly goopy/green snotty nose.

A behavioral problem has been somewhat high on the list of causes, although we've been hoping for something physical.

We can't see any skin problems with Macho. His coat is shiny and his condition is good. He's a 12 YO QH with no Impressive or Poco Bueno breeding, so is not likely to have any of the known genetic diseases.

The vet did perform a neurologic exam at the first visit and found no deficiencies. He hasn't been stumbling or weak and he can turn tight circles quite well, pivoting on either the hind or on the forehand. His appetite has been OK, although there have been some days when he's not eating as much hay.

We are in Southern Wisconsin and WNV is not usually an issue this early in the season. There was an outbreak of the neurologic form of EHV about an hour north of us, in Madison, so that was on the list of possibilities early on. Macho is vaccinated for WNV, EWT, Flu/Rhino, PHF, and Rabies. As a matter of fact, his symptoms started about 3 days after he received his spring vaccines (administered by the barn's vet, the BO was there, but no one else).

Does Fumonisin appear in any grain except corn? Macho used to get corn in his diet, but was switched to the Rice bran last fall, and gets no other grain.

I have no idea what Astragalus or Oxytropis looks like, so I'll have to do some research to see if those are possibilities.

Thanks again.
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