Pastern dermatitis

[Harriet1]

@Amberley

if it’s just the white legs it’s probably something that is UV mediated. I would try the white pull on socks for a while.

This.

I have a horse with white socks that has issues every year due to certain things in the pasture, and photosensitivity. It manifests like scratches, but the real problem is photosensitivity.

I haven’t tried pull on socks, but I have made a habit of clipping, a nighttime turnout schedule, and using LOTS of desitin. The desitin seems both soothing, and protective. I haven’t tried pull found that the zinc equiderma paste can be too harsh and drying once the skin is inflamed and there are scabs present.

[RedHorses]

Mine took longer than a week, but it was quite soon after I ran out of the copper/zinc supplement. The crusty patches started falling away pretty quickly after adding the supplement back in.

[PaddockWood]

@CanteringCarrot

My horse recently ran out of his copper/zinc supplement, and within a week has developed a very mild case of pastern dermatitis. My DH was making up feeds (prepped 12 days at a time in containers) and forgot to mention that he was out. I went to make up feed and noticed this.

@RedHorses

Mine took longer than a week, but it was quite soon after I ran out of the copper/zinc supplement. The crusty patches started falling away pretty quickly after adding the supplement back in.

And anyone who tests hay sees that copper and zinc are barely present so it makes SO much sense we need these supplemented. Do we think most/many owners and vets now understand the importance and check their feed sources?

[JB]

To be fair, I’ve seen some hay analyses with enough cu and zn to cover the basic needs, but they’re not the norm at all. The vast majority cover 1/2 to maybe 3/4 of the basic need

Keep in mind too that “basic need” is according to the NRC research, and they themselves admit that a lot of this is likely just bare bones minimums to not actively cause disease status. Certainly it’s been shown that far more horses than “should”, need more cu/zn than the average 100mg, in order to keep sun bleaching to a minimun, as well as hoof and skin issues away

@PaddockWood

Do we think most/many owners and vets now understand the importance and check their feed sources?

Nope

Hay testing still isn’t the norm. Some areas of the country seem to be a lot better than others, and even in those areas there are still pockets where farmers don’t test, and owners can’t get enough hay from a single source to make testing feasible.

But it DOES seem to be gaining steam from the point of not only farmers testing, but owners wanting to test when it’s feasible.

On this topic, vets seem to generally be lagging behind the owners, at least IME.

[Mouse_amp_Bay]

@CanteringCarrot

My horse recently ran out of his copper/zinc supplement, and within a week has developed a very mild case of pastern dermatitis. … It’s not coincidence that this horse has some pastern dermatitis since he stopped receiving this supplement. So I cannot emphasize enough how much that can play a role.

Same experience here. 4 white socks and lots of turn out to keep brain & body happy. I can essentially trigger a scratches type reaction by pulling the copper/zinc supplement for more than a week. Best way to keep it a bay is to keep “over supplementing” the copper and zinc… it maybe more than most need, but it is what is needed!

[Texarkana]

This thread is a hoot. Every horse person has their own theories and cure.

(This is not judgment; I have my own theories and concoctions too!)

[RedHorses]

I do think scratches/mud fever/ pastern dermatitis has a significant regional component. And a fungal vs bacterial vs both component. And a seasonal component. And a horse health component. And a horse management component. Etcetera.

I’ve dealt with it several times at different barns with the same horse, with different horses, at the same and different times of year, in similar and different turnout conditions. I haven’t found anything consistently worked.

[JB]

Scratches does have a lot of causes, bacterial, fungal, photosensitivity, allergies, parasites, and probably more. The connecting factor is the immune system, which copper and zinc play a very important role in. SOD - superoxide dismutase - is a critical component of the immune system, and 4 minerals in particular make up 4 SODs - iron, manganese, copper, and zinc. Fe and Mn are in no shortage in the vast majority of diets, through forage alone. It’s cu and zn which are often low. That’s why boosting those 2 makes such a big difference for a lot of horses.

But, the immune system isn’t that simple, so adding cu/zn doesn’t mean it’s a guaranteed fix. But it DOES work in a whole lot of cases, and like Mouse said, sometimes it’s about adding a good deal more than you think should work. And IME, the darker the horse’s coat, the more cu/zn it takes. Cu/zn also play important roles in skin health, which is needed to help the skin be the protective barrier it’s supposed to be. Other nutrients do that too, like Vit E and selenium.

Rain rot is different, also immune related, caused by the gram-positive bacteria Dermatophilus congolensis, but it actually has some fungal properties IIRC.

The bacteria that cause these things live in the world, in the soil, on animals in general. But since the causes of scratches are a lot more varied, it depends on the actual cause for a given situation as to which treatment works best. That’s why some have to add a dewormer, some have to add an anti-fungal, etc

[Ghazzu]

Aside from its involvement in the immune system, zinc is directly involved with epidermal integrity.
Zinc-responsive dermatoses are well-documented in veterinary medicine in multiple species, and I doubt anyone escapes 4 years of veterinary school without encountering same.

[PaddockWood]

@JB

SOD - superoxide dismutase - is a critical component of the immune system, and 4 minerals in particular make up 4 SODs - iron, manganese, copper, and zinc.

SUPER geek out moment! I have never read what you just said. Yes, I’ve seen manganese so high in most of my test results. And often Iron but know so many say that it might not be an accurate result on the iron?

And why the darker the coat the more that is needed? So fascinating.

[JB]

@PaddockWood

And often Iron but know so many say that it might not be an accurate result on the iron?

it’s true, but it’s the best we have right now unless you wanted to get into super $$$ testing to determine how much of what type of iron there is. Surface contamination, aka dirt, is typically not terribly bioavailable. That’s why if you see Fe really high, it’s worth submitting another sample, but rinse the hay, dry it, then submit it. And, not all the Fe in the hay is bioavailable either, but I don’t know what research is out there showing on average what % that might be, or if it’s just too variable. Certainly the higher the indigestible fiber content, the lower nutrient availability all around.

@PaddockWood

And why the darker the coat the more that is needed?

Color comes from pigment which contains melanin which requires copper So, the darker the color, the more melanine required which means more copper. That’s how a copper “deficiency” - not enough to cause disease, or even allow scratches or rain rot to take hold - can still be a deficiency when it comes to optimal coat health to minimize the sun fading as much as the rest of the genetics allow