What is equine pastern dermatitis (EPD)?


Equine Pastern Dermatitis is a huge term that applies to many types (and therefore causes) of skin problems in horses.


I’m going to preface this article with one notice here – there are some photos that may be hard to look at, so I have put them all together at the bottom of this article. The photos sprinkled throughout are all “AFTER” shots. 


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  • Equine pastern dermatitis is the giant umbrella term for an assortment of lower leg skin conditions of the horse. You may have heard terms like scratches, dew poisoning, mud fever, and greasy heel.


  • EPD is a syndrome, not a specific diagnosis, and has a multitude of possible causes. You will usually have some of the following: scabs, inflammation of the skin, lesions or sores, blisters, lameness (!!), hair loss, redness of the skin, crusty hair, blisters, lizard-like skin, itchiness, and even oozing and thickening of the skin. None of this is comfortable for your horse.


  • Some vets call milder cases scratches, in which you typically see a bit of inflammation and some scabs. Are they itchy and/or painful? Sometimes. There’s also an element of alopecia (hair loss) involved.


  • As things worsen, the skin can start to redden, slough away, and ooze. That ooze, for lack of a less gross term, is technically exudate, which can be more like pus or more like clear fluid, or somewhere in between. There may be blisters, and there’s definitely obvious inflammation. In cases like this, where the condition becomes exudative, many call it greasy heel.

Complications of EPD


  • Things can get even worse, and for some horrible reason, someone equated this stage of EPD as “grapes” which almost ruins the whole wine thing for me. This stage is the most severe, and the skin on your horse’s leg can thicken, get scaly, and develop nodules. At this point, things are chronic.


  • What makes EPD even more frustrating is that the lower leg’s skin is taut by design, and with every step, the damaged skin, scabs, and sores can flex and stretch, creating cracks in the skin. This causes a major traffic jam in the healing process and creates a lovely entry place for secondary infections to take hold.


horse A after treatment for EPD

Horse A, after EPD has mostly cleared up. All of the lovely leg models in this article wore Silver Whinny’s socks to clear up.


What causes EPD in horses?


  • Pull up a chair, we may be here a while. Because EPD is a condition, it’s made up of lots of possibilities, each with its own set of causes. Some overlap, some don’t. It’s a hot mess.


Perhaps you have heard of photosensitivity?


  • This condition often plagues horses with white legs and typically happens when your horse has eaten something or has liver issues. Light skin becomes easily burned in UV light. The skin becomes scabby and literally falls off. Many horses with photosensitivity act out when in direct sunlight due to the pain of this condition. More on this fascinating condition here.

There’s also pastern leukocytoclasic vasculitis.


  • This is another UV-related condition. Your horse’s immune system is part of the issue here, and will damage the blood vessel walls from within your horse’s body. This creates sores, which are amplified with UV light.


And then there are plain ol’ allergies.


  • Is it the grass? Some fabric or component of your horse’s sport boots? Detergent that you wash them in? A food allergy? Fly spray? Dust? Pollen? As we know from previous discussions about allergies, it’s important to run some blood and/or elimination tests to narrow down possible triggers.


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Of course, there’s the ever-popular folliculitis.


  • This is a fancy way of saying infected hair follicles. The infection could be from bacteria, which is literally on and in every single thing on the planet. There’s also a change of a ringworm infection, which is not a worm but a fungus instead. Still no answer about why they can’t change the name to ring-fungus or something more logical.


And what about that stuff called mange?


  • If you have ever seen one of those tear-jerking photos of a stray dog with barely any hair and scaly skin, you have likely seen mange in full force. Horses are also susceptible to mange.

white horse leg with some scabs

Horse B after treatment for EPD.


Talk to your vet about equine pastern dermatitis!   


  • I can’t stress this enough – especially when it comes to EPD – there are SO MANY CAUSES that you need to get your vet involved early. There’s no use spinning your wheels using diaper cream or some other home remedy when the cause may be internal, or sunlight-related, or fungal, or bacterial.


  • The same goes for picking, or not picking scabs. Picking scabs not only is painful for your horse, which is a perfect way to lose a willing patient, but can open the damaged tissue to new infections and bacteria. Your vet should provide you with a comprehensive plan that includes handling scabs.


  • Know thine scab-causing enemy before you start hurling all the random (and questionable) stuff that non-doctors toss around. You may well find that someone else’s idea for handling dermatitis is actually making it worse.


How do you narrow down possible causes?


  • Thankfully your vet has gobs of tools and tests to help narrow down the cause of your horse’s troubles. It starts with you, giving your vet all of the deets about what you noticed, when, and under what conditions. Are things itchy? Oozing? Cracking open? What’s the weather and footing and mud been like?


  • There are lab tests that can be run, like a skin scraping. This simple procedure looks for mites and mange. Or a hair and skin sample will be taken for biopsy. Allergy tests, liver function tests, and even basic bloodwork to look for the presence of infections can all be run.


no more scabs on horse C

Horse C after treatment.


What makes EPD more likely in horses?


Environmental conditions.


  • It’s logical that damp, wet, and muddy conditions trap questionable soil and poop and what-not next to your horse’s skin. Wet and dirty is like a petri dish of bad potpourri growing on your horse. Will every horse that has muddy legs get EPD? No, but it can play a role.


  • One of the major predisposing factors to EPD is prolonged exposure to mud which is why so many horses suffer from mud fever/ greasy heel most dramatically and tenaciously during wet months.


  • There’s a point at which your horse’s bedding, pasture, turnout, even arena footing can influence the health of the skin on his legs. It’s not always mud, there can be lots of smaller contributing factors. Bedding and footing are just two of them!




  • A horse’s genetic makeup can influence his allergies, his immune system, his likely hood of developing an auto-immune condition, and even how much sebum he makes. Sebum is the natural oil on his skin that creates that shine and bloom, and it also has anti-bacterial factors to it. So yeah, sebum is also part of your horse’s immune system. The literal first line of defense.




  • Closely linked to genetics is your horse’s lower leg hair. Is it feathered or not? Some feathered horses trap moisture and carry on their own scab-inducing science experiments in all of that hair. Some are not. It’s the veterinary consensus that feathers seem to complicate EPD, instead of ward it off. While it’s nice to honor your horse’s breed and traditional characteristics by keeping feathers, it might be wise to keep them clipped or shortened if EPD is something you battle.



  • It’s not just allergens that can live in your horse’s diet. There are aspects of diet, like some plants in pasture, that create photosensitivity. Or, your horse’s diet is missing some key ingredients that support skin and coat health and immune support. There’s a lot to be said about Omega-3 fatty acids in this respect, although much more research needs to be done. An Equine Nutritionist is your best source for making sure your horse’s diet is appropriate for his health.


no more scabs on horse C
Horse D after treatment.


How to help the horse with equine pastern dermatitis


Don’t change a whole lot of stuff at once.


  • Maybe you cannot even stop your horse’s constant exposure to mud but make the changes scientifically one thing at a time so you can figure out what changes are helping, and changes that are not contributing to wellness at all. Throwing the kitchen sink at it often results in healing going backward.


As with everything – your hands and eyes are the first, and best, thing to use.


  • It’s always a good idea to memorize your horse, and then examine your horse daily for anything new. It’s not enough to just swipe a brush or two over your horse, get in there with your fingers!


Let his skin be his skin.


  • Detergents (like dish soap) and harsh shampoos are designed to strip away grease. That includes that very precious sebum that your horse makes himself. Fun fact about sebum – it’s a natural stain repellent, so when you let it build up, everything is easier to clean.


  • Dr. Erica Lacher of Springhill Equine says “Dilution is the solution to the pollution.” Plain water rinsing can do more to clean tissue and help healing. Gentle rinsing, never scrub, that poor injured skin. That is another way to turn your horse against your efforts. Keep it simple goes a long way here.


Use a barrier method to protect your horse’s legs.


  • Just as using a sheet the night before a show to keep your horse clean, use socks to provide a barrier to outside forces on your horse’s legs. Silver Whinny’s socks work in a few different ways. They can absolutely help prevent and clear up dermatitis on horse legs. The socks ward off moisture and keep insects and dirt off your horse’s legs.


  • The antimicrobial silver in their yarn separates the damaged skin tissue from outside hazards, be they allergies, sources of bacteria, fungi, and the socks are able to protect skin with UV sensitivities. They simply create the necessary environment around the legs that are hostile to the continued propagation of bacteria and fungi.


  • Even if you can figure out what allergens are causing your horse to suffer, it may be impossible to remove those allergens from the environment or move your horse to another location. The next best thing is to use a barrier, like the Silver Whinny’s socks.


horse wearing sox for horses on mat

Yes, horses can wear socks.


Fight from all other directions for the best chances of healing Equine Pastern Dermatitis.


  • Use clean brushes, clean polo wraps, and clean sport boots. And saddle pads and tack, for that matter.


  • Get diligent about poop pick-up. eColi, among dozens and dozens and dozens of other bacteria, lives in manure. It’s tempting to skip cleaning larger dry lots and paddocks, but once you get into the daily routine, it’s easy. This also helps prevent intestinal parasites from multiplying through the horses in the barn. And it keeps flies away. SO MANY good reasons to do all of the scooping.


  • Keep your horse’s bedding clean. Whatever method you use, the barely-there shavings or the deep litter system, keep it all fresh.


  • See if your horse’s turnout schedule can work around the morning dew. If photosensitivity is a problem, use socks, boots, and/or a night turnout schedule to keep the UV rays off your horse.


  • There are treatments that can help your horse with EPD – but narrowing down the cause is important. There’s no use in using antibiotics if UV light is a major factor. Just like there’s no use in treating an allergy with a different turnout schedule.


Equine Pastern Dermatitis is a marathon, not a sprint, with lots of different stages and plans of attack. Work with your vet from the very beginning. Tackle all possible angles of triggers.


And this is the point to stop scrolling unless you want to see the BEFORE photos.  But you can skip to the SHOPPING section if you like. 


AND NOW ….the “before” photos. All of these horses wore Silver Whinny’s and had vet help in the healing process.


healing EPD on white horse leg

Horse A before.


EPD on white part of lower horse leg

Before, Horse B


Horse named C has large scabs around the pastern

Horse C before.


scratches in horse pastern horse named D

Before, Horse D.



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