Can we discuss Sellenium?

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Well-Known Member
Nov 30, 2002
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I'm admitting that my ignorance was hanging out regarding Sellenium.

When Timmy was born he was walking on his pasturns. I thought he was going to stand up on his own when he un-foalded but he didn't. The next day the vet came and gave him an exam and an IGG test and said he was perfect. She was new right out of school, and my regular vet sent her since her husband had just been killed that day in a wreck. But those feet bothered me a lot. He was only standing on 1 hoof. The other three did not touch the ground. But the vet was not concerend and said he would be fine. I waited for a few days and no change.

The phone rang and there was Judy from Zachary Farms over in Knoxville explaining that he needed sellenium and she did not know why the vet did not give him a shot of it. She told me that our area is very deficient in it and he needed it right away. Holly should have also had some before delivery. Judy promised me that if we put out the Purina 12 12 free choice minerals or get Sellenium and give it and he would it that he'd be right up on those feet with the help of Jerry squaring off the toes for him.

The crazy thing is that I did have all sorts of minerals out there with Holly in the dry lot for quite some time. But weeks before foaling, it rained every day and the holder was always floating with them so I just took it all away and said to heck with wasting this. How dumb? I just did not know.

Talked to Robin C and she gave me the run down on the sellinium. Seems that everyone east of the Mississippi River is sellenium deficient and lots of foals do this if they're mothers are deficient. Who'd a thunk?????

Holy cow, I just had no clue but now I know better.

Timmy was right up and on his feet like he should have been after just two raspings from Jerry, one week apart. Kid can run like a maniac too. Kid even set up square on those nice straight legs of his for me for a second there too a couple of times!

I must admit that our witty Carol Albritton made the funniest comment that had me in stictches over this. When I told her that Timmy was eating the heck out of the 50 lb trace mineral block non-stop that it worried me that he was getting too much of it. Her comment was "Well.......I wouldn't worry too much unless his eyes began to glow!!!!!!"
Way to go Carol

My question is what form of sellinium are you providing and where do you get it?

What other benefits are there from using sellenium?

I sure don't ever want this to happen again.
Marty said:
Talked to Robin C and she gave me the run down on the sellinium. Seems that everyone east of the Mississippi River is sellenium deficient and lots of foals do this if they're mothers are deficient. Who'd a thunk?????


Selenium deficency is wide spread in the US and not just east of the Mississppi River. We have selenium fortified supplements and you can find them at any farm/feed store. If not, then online. I'm sure Farnam has one too, pretty reasonably priced.

Selenium is one of those minerals included in salt/mineral blocks and in most of the manufactured grain pelleted feeds. It's found in the soil and consequently will leech into whatever is growing. However, there are large sections of the country that is either deficient in it or has too much of it.

Lack of selenium can cause "White Muscle Disease" and one of the very early symptoms that is most visible in foals is lax tendons in their legs.

Having your broodmare maintained on a good all around diet that includes selenium through her pregnancy will help the foal inutero. In addition, many vets will advise that the foal be given an SE/E shot at birth. This is a combination of selenium and vitamin E. (For goats and llamas it's a shot of Selenium and vitamin B.)

We keep a vial of SE/E in our foaling kit and give the shot to each newborn ourselves, however some people will have their vet give it during a 24 hour mare & foal check up.

(This may be more info than you wanted, but.....) We have had foals who STILL had lax tendons after all our precautions and we gave them an additional dose of the SE/E, plus trimmed their hooves before they straightened up.

Need to mention at the end of all this -- WE are not only deficient in selenium, we are totally LACKING in it. However, there are regions in the US that actually have TOO MUCH and doing what we do would be totally detramental. If anyone isn't sure of what region they live in, they should check with their vet.

In our blended feed (not a total ration just a good blended sweet feed) selemium is one of the trace minerals added to it. They seem to get all they are required by way of the feed and mineral blocks.
Why didn't I have this problem in Florida? I had three QH foals there and my friends had foals too. Never had this happen. Is it mostly a mini thing?
I'm not sure if Florida is deficient in selenium or not. However, I do suspect that minis are more sensitive to it than big horses.

Hi Marty,

This map (there are others) shows where selenium is low, adequate or high and also explains why based on the type of rock your soil is/was composed of.

Selenium Map

We live in a low area, with spots of adequate to high. We're on hills and have better selenium levels than the surrounding flat land. You do need to check where your feed is grown (if out of your area) for selenium levels too and if you supplement different feeds, etc., the overall amount of selenium given. To much is as bad as to little.

As for giving Selenium, we have the selenium blocks out most of the year, and give a VitE/Sel shot to all our horses in the Spring. Pregnant mares get in prior to foaling along with their vaccinations. Occasionally I've had a foal that need a bit more - loose tendons, etc.

It is a painful shot as it's thick fluid, so needs a thicker needle, so horses aren't thrilled, fortunately it's only one shot and we massage the area to distribute it well after we give it.
Marty is your foal licking on a salt block?

I´m sorry to say but that can be harmfull to foals, it will hurt his kidneys if he eats too much and he can get very heavy diarrhoea, and get de-hydrated.
As usual nothing is as simple as black or white.......lots of shades of grey here. Boggles the mind.

Yes Meavy, Timmy had been absolutely eating and trying to chew on the 50 lbs red trace/salt mineral block like you can't believe for a couple of days. It was in the stall so I finally became worried that too much of that would hurt him and I re moved it. Now, every day on his way out to play, he stops at the block and eats on it for a few minutes.

I have out:

white salt block

red trace/mineral block

purina 12 12 free choice minerals
Talked to Robin C and she gave me the run down on the sellinium. Seems that everyone east of the Mississippi River is sellenium deficient and lots of foals do this if they're mothers are deficient.
It IS true that there are other areas in the US which are selenium deficient, but since Marty is east of the Mississippi, this is what we discussed. In fact, there are only a few pockets in the US where selenium is quite high. The above link to the US map should help you determine how your property stands in terms of selenium levels.

In terms of pregnant mares, the fetus stores selenium obtained from the mother during pregnancy. Selenium levels in mare milk are low. Recommendation, according to Dr Van Saun /, indicates 2.5-3 mg per 1000# of nonpregnant weight per day until foals are born. That would calculate to approximately .5-.75 mg per 250 lbs of NON-pregnant weight in a broodmare.

Most selenium levels are expressed on the feed tag as ppm (parts per million), so if selenium is listed as 3.5 ppm (most feeds will be MUCH less than this), that means for 1 million grams of the feed, there is 3.5 grams of selenium, so -- for every kilo of feed (1 kilo = 1000 grams), there is 0.0035 grams of selenium or 3.5 mg of selenium. A kilo = about 2.54 lbs. So if you're feeding 2 lbs of our example feed (to our 1000 lb big horse), the horse is getting about 2.8 mg of selenium. To convert that to our 250 lb mini, he would receive .7 mg of selenium when fed 1/2 lb of this same feed.

Keep in mind, though, that there are lots of things that affect ABSORPTION of selenium, including the presence of vitamin E, and sulfur, such as the sulfate forms of copper and zinc which are commonly found in feeds and supplements. Even the common supplement, MSM, which is a sulfur source may block absorption to some degree.

Keep in mind that even hays that are grown on moderate to high selenium soils will not accumulate enough selenium to be toxic in most cases according to Dr. Eleanor Kellon However, there are several species of plants that accumulate up to 1000 times more selenium than the local grasses and are extremely dangerous. Thus acute poisonings could occur in those isolated pockets of high selenium where these plants grow.

Keep in mind that ingredients from feeds are obtained from all over the country. It would be next to impossible to determine if the oats or corn in your feed came from a selenium-deficient or a selenium abundant area. Also read the previous paragraph -- these are not the typical plants that uptake toxic levels of selenium.

An easy way to determine selenium levels in your horses -- if you have a concern -- is to run a simple blood test. Selenium is an important part of your mini's diet and levels should be carefully determined, especially in broodstock. If you are feeding a ration balancer (a highly concentrated protein, vitamin and mineral source) you are probably less likely to need supplementation than if you are feeding a primarily forage diet, or just small amounts of a commercial grain product vs. the guaranteed analysis. Also remember to take a look at that map to see where you stand in terms of naturally occurring selenium. Eastern seaboard people, you can pretty much figure you're deficient.

Robin C
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I am in WA state and we are also known for lack of selienum...)o;

You are making me think new mini can reach into the feed trauf and get to her block. I used to use this pen for my big horses..After work today I will go fix that! lol...

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