Wood chips that hopefully don't but might contain black walnut

[QuestionMark]

I’m wondering about wood chips that are already on the ground in a pasture. Since I don’t know 100% that they don’t contain black walnut (there was a breakdown in communication; i.e. I was told they were horse safe but later learned they were not guaranteed to be black walnut-free) but none of the horses have developed any laminitic symptoms since the chips arrived several weeks ago, does that mean we are in the clear?

They have definitely spent time standing on them and picking through them, but are also not standing on them for many hours like they would in a bedded stall. Would they have definitely reacted already if black walnut was in there? Is there any chance that when it rains the toxin (if it is in there) could become more potent?

Have you ever seen a horse react to this toxin with symptoms that did NOT look like laminitis?

[goodhors]

Why take the chance using chips if it can cause laminitus? Better to remove the chips if possible, use them outside the pasture as mulch or fill. If you can’t move the chips perhaps you could cover them with deep, used bedding or new, good sawdust, fence them off?

My friend’s horse got laminitus bedded on a bag of mixed sawdust from another friend’s workshop. She used it as bedding, then horse legs swelled by the next morning. Called the 2ND friend, “Yeah, he had cut a couple black walnut boards. So there was a bit of BW sawdust in the bag”. Horse had absorbed the toxic jugalone thru her hooves. Just ugly having to deal with it on such a nice horse. Never quite the same after.

[QuestionMark]

The information came to light literally last night, so I’m trying to formulate a plan now. The chips are unfortunately spread throughout large parts of the pasture and I’m not sure if we can remove them 100% (obviously if it seems necessary we will make every effort to remove them but I hear even tiny amounts of wood dust being left behind in the soil can still be toxic). Removal and/or keeping the horses out of the area would represent a major management change (and I am not the property owner). But if nobody has reacted by now, do I even need to be as worried as I am? Did we dodge a huge bullet or could they still be in danger?

[candyappy]

Why would anyone spread wood chips on a pasture in the first place?? Can you track down who spread them and find out where they came from? If Black walnut trees are common in your area ( like mine) I would do my best to find out if I could.

[Heinz_57]

@candyappy

Why would anyone spread wood chips on a pasture in the first place??

Some consider it a mud remediation, although not a long term one since they break down relatively quickly. I actually put wood chips as footing in my outdoor arena as a short term thing, until we are done with house remodeling and I can justify spending $$$$ on rock and sand.

OP, I read an article from Purdue that said symptoms usually appear within 24-48 hours, but that was for stall bedding. And it didn’t specify if that timeframe was consecutive hours or cumulative. If they’ve been out on it for weeks already, I would guess that you’d have seen trouble by now if there was anything to worry about. You might call and ask your vet to be safe, or post on Horse Vet Corner on FB.

[QuestionMark]

Thank you for your thoughts and opinion! I did speak to my vet and she said she feels the risk is close to non-existent at this point given the time frame.

I am certainly using this as an opportunity to educate the well-meaning folks who put the chips down (yes, as mud remediation).

[goodhors]

Actually, spreading wood chips or sawdust will make mud worse in the long run because they both breakdown over time. You go from “plain mud” to deep, goopy stuff when wet. And it stays goop when wet for longer times than the plain dirt used to.

Adding organic matter can be helpful to clay soils, but it needs to be thin layers, like using a manure spreader leaves, then lightly disced into the soil come spring to add air to open the soil.

Guess I would agree with the Vet if chips have been down a while with no issues. A york/landscape rake could be useful in gathering up the chips, should this be a problem in the future or someone surprises you with a dumped load.

I have had good luck smoothing off muddy paddocks using an old tractor tire, dragging it behind the tractor. Smooth mud seems to dry faster, fills the hoofprints, so for a bit things are nice. Pick a day when mud is not soup or frozen, avoid the very wet places so you do not get stuck or make mud worse.