Selenium

[Amy3996]

Consulting the COTH hive mind because this question didn’t occur to me until I was off the phone with the vet this morning. We ran routine labs for Vit E/Se on my 9yo OTTB as part of his spring wellness visit a couple of weeks ago. We’re located in geographically low Selenium area.

E came back WNL, Se was high normal at 22. Vet said they didn’t want to see the Se value above 24 (I don’t have the lab report in front of me to clarify the unit of measure on that so bear with me please). He’s been off any supplemental Se for about a year and a half after his last labs came back at 20. He gets 5lbs of Purina Impact Performance, 1lb of Nutrena Boost, and free choice grass hay. His only other supplements are Grand Calm for Magnesium and Santa Cruz for Vit E.

The Impact GA lists the Se value at 0.60ppm. I’m terrible at number crunching, so I don’t know if that’s adding a meaningful amount of Se or not.

Long winded way of asking… how would I hypothetically manage his Se if he creeps up into that 24 range even without supplementing it? Switch to a feed with no added Selenium? Do those exist?

[Simkie]

PPM = mg per kg

5 lb = 2.268 kg

2.268 kg x 0.60 = 1.36 mg selenium

No, that’s really not particularly significant

The selenium test my vet runs reports in ng/mL and the normal range is 120-180. When we were in Colorado, my horse was pretty significantly out of range (it’s been awhile, but I want to say in the 600 ballpark??) (CO is a high selenium state) but there’s a large buffer between “out of range” and problem territory, and the vet was unconcerned.

Without the units, it’s tough to compare, but if 22 is within range, 24 does not seem like it would be worrisome.

[Amy3996]

Got a copy of the lab report. The bit about toxicity being an issue closer to 110mg/uL would have been helpful context in my conversation with the vet.

[George_T_Mule]

@Simkie

Without the units, it’s tough to compare, but if 22 is within range, 24 does not seem like it would be worrisome.

I will add that Selenium is toxic, to humans at least, tho I’d suppose to Equines and other Mammals as well. So if you are going to err, I’d say err on the low side.
However, I’m not Bio-tech, so take that with a grain of Sodium Chloride :-).

[Simkie]

@Amy3996

The bit about toxicity being an issue closer to 110mg/uL would have been helpful context in my conversation with the vet.

Yep! There’s a wide margin between “above normal range” and “oh shit”

[JB]

@George_T_Mule

I will add that Selenium is toxic, to humans at least, tho I’d suppose to Equines and other Mammals as well. So if you are going to err, I’d say err on the low side.

All minerals are toxic at some level.

Deficiency can be as bad, or worse than, a toxicity. Se deficiency causes very similar physical symptoms as toxicity.

Se isn’t toxic at nearly the relatively low levels many have come to believe

What’s interesting for the OP’s horse is that a year lager, his Se level has risen a bit more, coming off Se-containing supplement, but (I assume) remaining on 5lb of the Impact. Into dangerous territory? No, thankfully, but you also don’t want it to keep increasing year over year.

I don’t know off the top of my head of a regular feed that doesn’t contain Se. If there are some, they’re probably pretty region-specific, and available only in areas where forages are known to be quite high.

Your other option, if things keep creeping up, is to use a forage balancer like Vermont Blend or California Trace in the no-Se formulas. I’m fairly certain there are other names as well, probably KIS Trace and maybe some others, that have Se-free versions. Then you’d use that, and replace the calories with things like alfalfa pellets and maybe a little rice bran.

For now, I’d probably stay the course, and see what his level is next year, and decide then

[DiamondJubilee]

A little off topic, but selenium and toxicity always reminds me of the compounding pharmacy in FL that made a vitamin mixture for a bunch of polo ponies and 21 of them died right after injection (millions of $ worth of polo ponies!!). It came back as selenium poisoning.

I work in Canada at a very busy compounding vet pharmacy so it really sticks out to me (and the pharmacy was sued and was shut down). They compounded the selenium in mg instead of mcg, something the pharmacists didn’t catch (but perhaps they were thinking it was for horses and the dosing would be ok? Who knows).

Selenium Cause Of Polo Horse Deaths

I have an EMS pony who can’t have any grain, so I’m actually looking for supplements that contain the most amount of selenium for him (I did find Omneity and Vit E with Se from Mad Barn and he will eat this - he is an uber picky pony and turns his nose up at most feeds, unless its grain of course, which he can’t have). I’ve read some articles on the importance of Se, especially in EMS horses. 20mg for a 1,000lb horse should be the max, but most are getting 1mg or below. With my 2 new supplements I’m adding for my 730lb pony, he’s getting about 2.7mg plus just over 0.4mg in his hay cubes (around 3mg/day) which Mad Barn did analyze and its totally safe. I’m in Ontario and we are very Se deficient in our soils. I also had my hay tested to help balance my ponies feed.

[Simkie]

@DiamondJubilee

but most are getting 1mg or below

How do you figure? I recently took a look at a few different popular feeds and if fed according to the directions, selenium comes in around 2 mg.

Like Triple Crown Senior, 1ppm max selenium, 6 pounds per day, gives 2.7 mg Se

Or Enrich Plus, 2.4 ppm max selenium, 2 pounds per day, 2.16 mg Se

Etc etc.

[DiamondJubilee]

That was just mentioned in a podcast I was listening to Re: 1mg. But it was an EMS podcast, so it could have been because most are not fed any grain. I should have been more specific!

[JB]

@DiamondJubilee

That was just mentioned in a podcast I was listening to Re: 1mg. But it was an EMS podcast, so it could have been because most are not fed any grain. I should have been more specific!

Whose podcast? Even EMS horses need nutritional fortification. Even forage balancers, which a lot of EMS horses are on, have around 2mg a serving . Vermont Blend has 2mg, California Trace has 2mg, most of them have about that, and several of them also offer Se-free versions.

3.1mg for your pony should be fine, but you can always check his blood for the level and adjust from there. Obviously that doesn’t account for what might be in the hay, but Se testing of forage is very unreliable, and $$$$ to boot, so not worth it. But a low Se area does make much more likely that even over 3mg supplementation for even a pony, is fine

[DiamondJubilee]

I can’t remember the podcast, but I think she was saying if EMS horses were not fed any balancers/grain etc,(as in just hay/hay cubes/beet pulp) selenium levels are probably low, so it needs to be supplemented since its very important. I feed Ontario Dehy Timothy Balance cubes which has Se added and beet pulp as well (Se at 0.4mg/kg). It was made for EMS horses in mind and is considered a “safe” feed for EMS animals (on the safe list from Dr. Kellon). On Dr. Kellon’s safe feed list, most ration balances are not on there and she doesn’t consider them safe to feed to an EMS animal. I have a hard time finding a lot of her safe feed ones as I’m in Ontario and we don’t have the same ones here. I was feeding Purina Equalizer but it was not on the safe list (even though they say on their website its safe to feed due to low NSC). I have heard it has higher levels of iron in it, but I did not look into it since it wasn’t on the safe list anyway.

I haven’t checked my guys blood level for Se or tested my hay for it either, but I know I’m in a low Se area so I wasn’t too worried about it. I’m sure it would be far, far less than 10mg total, so I would consider that very safe.

[DiamondJubilee]

login

This is the safe feeds list on the ECIR group, which I’m a part of.

I can’t find any supplier in Ontario that sells Vermont Blend or California Trace Plus. My pony would not eat Amino Trace +, so I switched to Omneity pellets instead, which he will eat.

[JB]

@DiamondJubilee

I can’t remember the podcast, but I think she was saying if EMS horses were not fed any balancers/grain etc,(as in just hay/hay cubes/beet pulp) selenium levels are probably low, so it needs to be supplemented since its very important.

that’s not a terribly safe thing to say. Many areas have enough Se in the forage to provide what a horse needs. Granted, the typical addition 1-3mg in a min serving of most things isn’t enough to cause issues for most of those horse, but there are enough areas with higher levels of Se in forage to not want to do that.

Here’s a map showing soil concentrates of Se. The darker the blue, the more Se. Look how many counties are darker to very dark.
https://mrdata.usgs.gov/geochem/doc/averages/se/usa.html

Now, does that automatically translate to blood levels? No. But, you shouldn’t assume that Se levels are probably low simply because the horse is only eating hay/grass

@DiamondJubilee

I feed Ontario Dehy Timothy Balance cubes which has Se added and beet pulp as well (Se at 0.4mg/kg). It was made for EMS horses in mind and is considered a “safe” feed for EMS animals (on the safe list from Dr. Kellon). On Dr. Kellon’s safe feed list, most ration balances are not on there and she doesn’t consider them safe to feed to an EMS animal.

“Safe” in that context is referring to ESC + starch, it’s not about Se. But also, she and ECIR in general are VERY black and white on this, there’s no gray area for them, when reality proves that a lot of EMS horses do just fine on 1lb of a ration balancer that’s higher than the gold standard ECIR has set.

@DiamondJubilee

I was feeding Purina Equalizer but it was not on the safe list (even though they say on their website its safe to feed due to low NSC).

Purina doesn’t list wsc/esc/starch on their website for Equilizer, so I don’t know what it is

@DiamondJubilee

I have heard it has higher levels of iron in it, but I did not look into it since it wasn’t on the safe list anyway.

it’s listed as 1000ppm (mg/kg), which is pretty high for sure, but also not the evilness that many make it out to be - more info is needed

[DiamondJubilee]

This was the selenium map I was looking at as it incudes Ontario, so for sure we are on the low Se list:

7 Research-Backed Health Benefits of Selenium for Horses | Mad Barn

I have read that 0 added iron should be included in an EMS diet, so Equalizer at 1000ppm is a no go. I just don’t want to risk it. https://ecir.groups.io/g/main/files/6%20Diet%20Balancing/Acceptable%20commercial%20ration%20balancers/Acceptable%20Ration%20Balancers.pdf

I did reach out to Hoffman’s (Canadian made) rep and plan on trying their BalanceIR grain (on their safe list and has added Se) which lists all ingredients including 11% NSC and 2% starch.https://hoffmanshorseproducts.com/Product-BalancIR-Ration

Hopefully I can change to this grain and if I feed under their recommended amount (I do find it on the high end as I have never fed any of my ponies even 3kg/grain a day, usually 1kg at the most. They say to feed 3-8kg/day but I’m sure they are talking about 1000lb + horse, but I will have to see. My guy can do with more weight as he’s starting to get ribby and is a very picky eater) and I can add the Omneity pellets for vitamins, if I feed below their recommended weights. I was going to start with 2kg of BalanceIR, 2 cups flax (about 1lb), 1kg of balance timothy cubes, 60ml of W3 oil and 1 scoop of Omneity (100g). That would be about 2.8mg of Se and hopefully covers everything.
http://www.ontariodehy.com/assets/files/Timothy_Balance_Typical_analysis.pdf

Flax-Appeal.pdf

My guy of course is on a dry paddock so no grass. Hay was tested but I did not test for Se.

[JB]

@DiamondJubilee

I have read that 0 added iron should be included in an EMS diet,

Again, more context is needed. How much added, and what form? 100ppm of iron oxide in a 6oz serving isn’t going to move the needle, due to the low intake, and the very low bioavailability of that form. I agree that 1000ppm in even a balancer is a lot but also I’d want to know how much of that is intrinsic, and how much is added, AND, what form(s) there are. If they’re sourcing the bulk ingredients from a place that has lots of Fe in the soil, that’s one thing. I doubt they’re adding significant Fe, but it would be interesting to ask

@DiamondJubilee

Hay was tested but I did not test for Se.

don’t bother. Not only is it a $$$ test, it’s not reliable. Test the horse, that’s the only way.

[DiamondJubilee]

Thank you JB