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Scratches, Rain Rot, Dermatitis and Skin Allergies in the Horse

Scratches, rain rot, and skin allergies in the horse…oh my!  Skin problems in the horse are very, very common and at the top of complaints for many horse owners.  For most, they are easily resolved with a little attention, while for others, the skin problems fester and turn into real concerns.  Why are these problems so common in the horse and why are some so difficult to manage, no matter what you do?

Rain Rot and Scratches in the Horse
Rain Rot and Scratches in the Horse

The winter and spring time seem to be the main times of the year for certain skin conditions in the horse, while for others, the problems are present more so in the late spring and summer.  Why? The reality is that in order to understand the problems, you have to understand the concept of skin in the horse.  Along with that, you need to look below the skin surface, make connections, and in those connections the answers will become a little clearer.

The skin is a living organ, meant to provide a barrier of protection for the body.  This barrier is not just to repel moisture, but is a defense barrier for the invasion of bacteria, chemicals, and other potentially harmful substances.  When there is a skin related problem, be it allergies, dermatitis, rain rot, scratches or otherwise, it is a signal that the natural skin barrier is compromised.  Something has weakened it and now, you are seeing clinical manifestations of that compromise.

Now, keeping this in mind, anything you do to your horse topically can impair skin health and weaken those defenses.  This means any chemicals applied can create harm, which include fly sprays or other chemicals, including perfumes, shampoos, and conditioners.  No two horse’s skin is the same and just because you use a fly spray in one horse does not mean another will tolerate it.  If you irritate that skin surface and weaken it, then bacterial infections will likely occur and linger until you help to restrengthen what was weakened.

The skin is a living organ and as such, communicates with and reflects the health of the body and other organ systems.  The skin is dependent upon nutrients, just the same as any other part of your horse’s body, and thus diet and proper digestion are paramount.  If the diet is not correct or digestion is impaired, this will be reflected in a state where the skin is weakened and unhealthy.

Making Connections with Skin Conditions in the Horse

No matter the skin condition which is present, first, view it as a compromised state of health in your horse.  For some reason, the skin is not healthy and performing its defensive ability.  Bacteria have invaded, the skin is now irritated, and normal defenses are lost.  Why?

Let’s look at a few common complaints that I encounter with horses:

  1. Dandruff
  2. Rain Rot  (Florida Funk)
  3. Scratches  (Florida Funk)
  4. Skin Allergies

Dandruff in the horse is related to excessive shedding of skin cells on the outer layer or epidermis.  This dandruff can really come in two forms; large flake or small flake dander.  Discriminating between the two is important as it helps you to better resolve the issue.  Dandruff is more common in the powder or small flake form, especially during the dry times of the winter, as this tends to dry out the skin and cause excessive cell loss from the epidermis.  Despite how common or simple this may be, it is still a breakdown in the skin surface and a potential weakness.  Small flake dander is generally viewed as dryness, a blood deficiency from a Chinese perspective, and usually resolved not by using a shampoo, but by ‘feeding’ the body properly.  This comes from a higher plane of nutrition, ideally in whole-food form.  Higher quality hays, spirulina blue green algae, ground flax, or even a low level use of topical olive or flax oil on their grain.  Large flake dander is not due to dryness, but is actually attributed to ‘dampness’ in Chinese medicine and can be viewed as excess oils which have dried and are shedding from the skin surface.  This large flake dander relates back to the diet and digestive difficulties.  If you take the same approach as a small flake dander, you can easily upset the situation, more than help it.  In these cases, you have to address the digestive issues, then the skin will fall into place.

Rain rot, which includes the ‘Florida Funk’, is very common and most evident during wet times of the year, so it can be present during a wet winter or even the spring.  This is also noted in the southern climates where humidity is excessive.  The excessive moisture that is present tends to accumulate on the skin surface, mainly the horse’s back region, and create damage to the skin surface.  This is no different than you or I soaking our hands for a prolonged period of time.  The skin becomes water logged, saturated, and soon, the cells begin to lose their normal integrity.  Then, bacterial infections become problematic and the cycle continues with the bacteria invading and then creating their own damage.  While the main issue is the excessive water exposure, this is not always easy to resolve other than using a sheet or blanket in your horse, which may or may not help.  In most cases, the damp times are over, but the skin infections continue.  In order to resolve this, you must address skin health through feed, digestive health if needed, and focus on the immune response.  The immune response is what you need to enhance clearing of that bacteria, and once this is addressed properly along with digestive health and the diet, the skin usually rebounds uneventfully.

Scratches in the horse is not too dissimilar from rain rot.  Both, in my opinion, are related to excessive wet conditions, which aid in the breakdown of the normal skin health.  This then opens the door for bacterial infections, which then escalate and prolong the problem.  Scratches generally affects the back of the pastern region, the fetlock, or the heel in the horse and is associated with superficial and sometimes deep dermatitis or pyoderma.  This equates to a bacterial infection which is creating inflammation, discharge, scabs, redness and overall irritation for your horse.  The approach for these horses is the same as for rain rot.  A high percentage of ‘scratches’ horses have underlying digestive issues, which is then impacting the immune response.  This then leads to the ongoing cycle of events that many horse owners contend with and why so many fail to respond.  I am not against topical shampoos, but again, you have to realize that anything topical can and will irritate the skin further.  If you irritate that skin, you have just compromised it further, and opened the door for more invaders and problems. Personally, I will use a topical agent once daily for a few days to help reduce bacterial numbers, but mainly rely upon the diet, digestive support, and immune support to benefit that horse.  Most respond quite readily.

Skin allergies are rampant and result in all sorts of clinical problems from hives to complete hair loss, open sores, and tremendous irritation for the horse.  Allergies are sign that the immune response is not working properly, no matter whether if those allergies are involving the skin, the eyes, or the respiratory tract.  If your horse has skin allergies, then you need to think ‘immune response’.  While this may seem simple, and for some it is, the reality is that the immune response is tied back in with digestive health. So, a horse owner can use an ‘immune’ supplement, yet not receive benefits.  The reason for this is that the digestive tract is out of balance in most and a dysbiosis exists.  This dysbiosis is then triggering all sorts of inflammatory events in your horse’s digestive tract and impacting their immune response.  Unless you get the digestive issue under control, all efforts made will likely be futile to some degree.  In order to get the digestive response back to a healthy state, you must address the diet properly, and in most cases the horses benefit from specific herbal formula to encourage a state of balance.

A quick word on the “Florida Funk”, as most of our clients refer to.  This is a common skin ailment that is present in many horses in the southeast section of the United States.  In reality, it is nothing more than a condition similar to rain rot or scratches.  It is a bacterial infection, sometimes coupled with a secondary yeast or fungal invader, that is encouraged to develop due to very humid and damp conditions in that region.  In reality, the humidity is not a problem, but when problems develop, it signals there is excessive ‘dampness’ present within your horse.  The humidity in the environment is adding to an already ‘humid’ or damp state in your horse, thus creating problems.  Not all horses in the southeast develop skin problems and this is why.  Some are more ‘damp’ than others, not in location, but in the horse themselves.  Think of your horse as being a sponge that is already wet, and now you add more moisture to it.  It creates an ‘excess’ state and the skin breaks down, opening the door for infections. The root problem in these horses is digestive health and this must be the primary area of focus.

Correcting the Problem in the Horse

The bottom line in most of these ‘skin’ related cases, is:

  • Impairment of the immune response
  • Digestive health imbalance

The immune response is linked heavily with digestive health, so often both are addressed together.  Additionally, the immune response is dictated by the diet, what you are feeding, and how your horse is reacting to that chosen food regimen.

In order to resolve these skin issues in the horse, you have to take the time to analyze your horse’s diet and supplement regimen, not to mention any topical therapies you are using.  You should not only analyze nutrient intake, ideally in the whole food form, but also look closely at what offenders might be present which might be creating more issues than they are helping.  This takes time and some knowledge, but is not hard to do. One major tip is to look at the grains you are feeding as this influences many aspects of your horse’s health.  Here is a good article on this topic of grains.

Formulas that we utilize and recommend:

  1. Cur-OST EQ Total Support – benefits the inflammatory response, digestion, and provides a low base of whole food nutrition.
  2. Cur-OST EQ Immune Full Spectrum – benefits the immune and digestive response due to naturally present mushroom derived beta-glucans.
  3. Cur-OST EQ Tri-GUT – clinical proven formula to aid in helping to restore digestive microbiome imbalance in the horse, while also benefiting the inflammatory response
  4. Cur-OST EQ Pro-GUT – benefits the digestive response and microbial balance

The exact regimen that will provide benefits for any one horse can vary tremendously and is really dependent on how deep the problem goes and how willing the owner is to make dietary changes. For most of these skin horses, our base regimen is the Cur-OST EQ Total Support and the Cur-OST EQ Immune Full Spectrum.  Then, if problems are not improving in the first 14 days, the Cur-OST EQ Tri-GUT is added to the regimen.  Fecal cultures can provide real insight regarding digestive health and can guide with therapy options.

Skin challenges are common in the horse and impact our own private herd as well.  No one is immune from these ailments, but when they happen, it should signal that a problem is present and must be addressed.  Through the right approach, most are easily resolved, and then long-term management strategies can help minimize their impact in the future for your horse.


Author:  Tom Schell, D.V.M, CVCH, CHN






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