Responses to questions posed regarding a variety of skin conditions. Dr. Sandi Farris was the consulting Veterinarian.
Answer: There are a number of reasons that Satch could be itching, including bacterial and fungal infections of the skin, external parasites, seasonal allergies, or even just from habit. Look closely for lice in the mane and tail and on his body. They are not common but are seen more this time of the year and in the early spring, and are a major cause of itching. They have yellow bodies and red heads. Do this under bright direct sunlight; wait a few moments and watch for his "dandruff" to move. Lice do seem to prefer the coarser hairs of the mane and tail, and it only takes a few to make a horse itchy. Treatment consists of an over-the-counter lice powder or shampoo, repeated in 14 days. You've done well to keep him dewormed regularly, but it wouldn't hurt to have a fecal sample run by your vet clinic to double-check on the types and numbers of intestinal parasites he may have. Oxyuris is the commonly incriminated internal parasite to cause tail head rubbing. Bacteria and yeasts (fungi) are pretty common infections of the mane and tail after a season of hot weather, shows, training, and sweat-buildup. A Betadine-based shampoo of the areas, allowing the lather to sit on the skin for 10 minutes, will effectively clean and kill bacteria and fungi that may be harbored in the warm, moist skin under the mane and tail. I usually have owners spray Betadine solution on the affected areas twice a day (without rinsing) for a week with good results.
Finally, if you have performed all of these procedures and still have an itchy horse, ask your veterinarian about skin scrapings, fungal cultures, or even biopsy.
I have tried a water-based fly spray after 14 days of no spray. I only use it sparingly though and have a fly mask over her eyes. She is pastured at night and put in the barn during the day. I just purchased her in Dec., 2002 and do not know of any other year this might have happened to her. It has been a very wet, hot and humid summer.
Is it possible to be allergic to the oil-based fly spray?
Answer: I'm glad your mare is feeling better! I have had a number of horses in my practice show hypersensitivity to fly sprays this summer. Fly sprays generally contain a permethrin as the repellent, as well as "inactive" ingredients to add fragrance or to keep the ingredients in solution, and may be based in oil or in water. Any of these compounds can be allergenic to an individual horse, and repeated exposures are often necessary before the horse becomes allergic. A contact allergy, such as your mare experienced, often results in an inflamed, raw, crusty area where the solution has been applied. Continued contact can result in swelling and edema under the skin. Steroids and washing off the area are important in treating the contact allergy.
It can be difficult to determine which compound is the main allergen to your mare. Trials with a different spray, in small areas of her body at a time, are your best bet. Wait a few days before enlarging the exposure area to monitor her response. Stay away from sensitive tissue such as the nose, eyes, udder, or under her tail. In very sensitive horses who just can't tolerate sprays, I always recommend stable management tips for insect control such as fly strips and traps, fans, and darkened stalls during the day. Drain any standing water that may allow mosquitoes to breed. Continue to use head fly nets and fly scrim sheets as well.
Answer: This is a great question! I always say that if you ask ten horse folks about the treatment of scratches, you'll get ten different answers. There is a multitude of answers on the Internet chat sites; some seem to work and some don't.
The facts that are agreed upon at this point are that "scratches" consists of a mixed bacterial and fungal (yeast) infection, complicated by a local inflammatory or allergic response. As you may already know, scratches occurs most commonly on the back of the hind pasterns, so is referred to as "pastern dermatitis". Scratches does best in a wet environment, and the long hair on the backs of pasterns often collects and holds the water from a muddy ride, or the moisture left over from a bath. Occasionally a small laceration or roughened skin on the pastern will incite a bout of scratches. Effective treatment consists of drying the skin and applying a topical antibiotic, an antifungal, and an anti-inflammatory such as a steroid. In some of the more severe cases oral antibiotics and steroids are indicated.
Some horses who seem predisposed to multiple episodes of scratches may suffer from mild allergies or contact sensitivities as well. Stable management becomes even more important in theses cases to alleviate their pain and inflammation. Ensure that the corral is well-drained with no standing water. The grass in the pasture should be mowed to prevent excessive pollen and chaff from collecting on the horses legs. Dry the legs completely after a bath and each ride, and consider clipping the hair of the pasterns so that it cannot trap any extra moisture.
Answer: Allergies can be a huge frustration since it may be nearly impossible to determine exactly what caused the outbreak! Feed ingredients, grass or tree pollens, dust, mold spores, insects, leather, cat hair...the list is as long as you can imagine. In your mares case I might consider whether she is reacting to the oak trees, to dust, or to insects at dusk.
Many horses will experience at least one allergic reaction in their lives causing hives, facial swelling, itchy skin, open sores, or a chronic cough. Because it is so difficult to completely regulate the environment our horses live in we often treat symptomatically and never determine the actual allergen. Initial treatment may improve the hives and swelling, but some horses retain that itchy feeling and require more immune-specific medications.
The allergic response occurs when local immune-system cells react to the allergen by releasing histamine, a chemical that causes itching, swelling, and redness of the skin. Steroids act quickly to quiet that response by decreasing inflammation and are used first in an allergic episode. Antihistamines such as hydroxyzine or pyrilamine directly block the histamine response by binding to the histamine receptors on the skin cells. These medications are instituted on a longer-term basis to prevent the continued immune response, especially when we are unable to control the exposure, such as in cases of pollen allergies.
I find that many horses benefit from a week or more of Tri-Hist to dampen the over-stimulated immune response and prevent further reactions. Keep in mind that many of the antihistamines are not allowed in the show ring and alert your veterinarian if you have a show during the course of treatment.
Answer: If this is the only bald spot on your mare and it is not itchy, infected, or open I would wonder whether she had experienced trauma to the area with resultant scar tissue. Make sure that her halter and bridle nosebands fit correctly; not too tight and are set in the correct spot on her face. Hopefully she doesn't live in her halter all the time which would certainly wear on the delicate skin. Ensure that these pieces of equipment are clean since constant exposure to a dirty or wet halter can cause chronic skin conditions. You mentioned her sunburn; she may also be one of those REALLY sensitive horses who require a covering of wool on their nosebands to prevent skin irritation.
Emollient or petroleum-based creams such as Bag Balm or Corona would be useful to keep this affected area soft and prevent cracking. Remember not to use these products in an open wound or if you suspect a bacterial or fungal infection because they trap the organisms in and prevent healing.
As is the mainstay in longstanding dermatitis problems, you might consider asking your vet to do a punch biopsy and histopathology to have a definitive answer.
Answer: This is one of those dermatology problems that makes everyone squeamish, but fortunately can be treated and controlled by the horse owner. The nodules that you noticed are the result of a common house or stable fly depositing Habronema fly larvae into wounds or moist areas on the horses body. Occasionally these infective larvae will penetrate intact skin. The disease process is felt to be a hypersensitive reaction to the dead or dying larvae. Habronema nodules are commonly found on the legs, belly, within and around the eye, in wounds, or in the prepuce or penis. These areas can fester and ulcerate, causing itching and intermittent bleeding. The nodules are found to decrease spontaneously in winter, so that a horse purchased in the spring may suddenly show nodules in the summer, even in a region not usually troubled by Habronema.
The ideal diagnostic test is a skin biopsy which allows the veterinarian to differentiate these nodules from cancer or scar tissue lumps.
Treatment consists of quieting the immune response to the dead larvae and reducing the size of the nodules, and of course by preventing reinfestation. Steroids may be injected directly into the lumps, though some horses will require a course of oral steroids to decrease the inflammation. Oral ivermectin is useful to kill the larvae as they enter the skin and prevent them from starting a nodule reaction. The ivermectin, however, won't decrease the size of the initial lesions, and unfortunately the horse may remain "lumpy" for a long period of time.
Habronemiasis is a regional problem, occurring mainly in warmer climates. The best course of action is to prevent the larvae from entering the skin by controlling the fly population in the corrals and pastures, keeping a fly sheet on during the warmer parts of the day, and using a fly spray. If your area is known to have a problem each summer with Habronema, I would recommend monthly Ivermectin throughout the fly season.
Answer: In doing a bit of research on allergies I came upon both EqStim and EqStim products., the first being oral, the second a veterinary injectable. I have no experience with the oral EqStim. Their website describes the ingredient to be a natural substance derived from oats, and claim it stimulates the immune system.
The EqStim injectable product can be found on the Neogen Company website; it is an inactivated derivative of Propionibacterium acnes. It has been shown to stimulate and enhance the cell-mediated immunity in horses that are battling respiratory infections. It is approved for stimulating the immune response, and many veterinarians use it as an adjunct medication when treating immunosuppressive diseases. There are varying opinions on it's full efficacy in off-label uses such as allergies or hives. I would recommend discussing the protocol with your veterinarian.
Knowing all this, do you have any suggestions for me?
Answer: The first thing I ALWAYS check on miniatures is their tail, mane, and neck area for lice. It seems like these often shaggy guys are a haven for lice, even in the summer when they are shed out. Make sure to look for them in bright sunlight; they have yellowish bodies and red heads. It only takes a few to make these little horses itchy.
If your horse appears free of lice consider an allergic condition to dust or mold spores or any pollens currently flying about in your region. Hypersensitivities to insects will also create an itchy horse. Your veterinarian would be able to prescribe an oral antihistamine to dampen the immune response to an allergen. Many really itchy critters benefit from an oral medication when no external source for the itching can be found. You certainly want to stay away from steroids in such an easy-keeping mini, as they are already predisposed to laminitis (founder), and steroids can incite an acute case.
Make sure that her hay is not dusty or dry, shavings, straw or other bedding is not moldy, and consider wetting down her paddock to decrease dust. Clean all horizontal surfaces in her stall that will collect dust and mold. Some horses do better when their hay (even hay that appears "normal") is wet down thoroughly before feeding to decrease dust.
Shampooing her with an oatmeal-based equine shampoo, allowing the lather to sit on her skin for 10 minutes may decrease her itching. Some horses enjoy a 1:20 dilution of Aveeno bath oil in water, applied over her most itchy areas to "moisturize" the skin. (Test a very small area first to make sure she doesn't have a reaction to the product.)
Answer: What an interesting appearance Honey must now have! The good news is that the depigmentation is unlikely to cause her any health problems. The terms leukoderma and leukotrichia are used to describe pigmentation loss in skin and hair, respectively. It sounds as if Honey has both. Another term, vitiligo, refers to a skin depigmentation from an unknown cause.
Leukoderma and leukotrichia often develop in areas of trauma and inflammation; consider the white hair regrowth from saddle sores one sometimes sees under poorly fitting tack. Dermatology diseases such as onchocerca infestation, lupus, frostbite, burns, or sun damage can result in leukoderma. Reticulated (linear) leukotrichia is a genetic skin disorder found in Quarter Horses, Thoroughbreds, and Standardbreds. It appears as a broken or wavy line of depigmentation down the topline of these horses. The skin is otherwise completely normal; the hair color is the only change.
Hyperesthetic leukotrichia is also documented; in these cases the depigmented hairs are exquisitely painful. This form is quite rare. Spotted leukotrichia is similar to the reticulated, but appears instead as multiple, body-wide spots of hair depigmentation. Arabians may develop vitiligo, undergoing a skin depigmentation for unknown reasons. The areas may spontaneously repigment in a few years.
Treatments for the actual depigmentation consists of treating any obvious underlying disorder such as removing trauma, deworming, and preventing sunburn or frostbite. Steroids and anti-inflammatories have been attempted in some depigmentation cases with varying degrees of success. In Honey's case, your vet might consider testing her for discoid lupus erythematosus (DLE). Although DLE typically presents as initial crusts and hair loss on the face, it does result in both leukoderma and leukotrichia. It is a small possibility that Honey has an atypical presentation of DLE.
Answer: It can't be easy to prevent sunburn in Texas short of keeping him locked into a shaded area all day, or blanketing him with a thin summer sheet. I have had clients find success with sunscreens formulated for infants or children, used on all of the pink-skinned areas. I would suggest testing a small area first for a 24-hour period to ensure the sunscreen doesn't cause him an allergic reaction.
Answer: The pattern of the skin lesions, and the severe amount of "itchiness" (medically termed pruritus) leads me to put a parasite or fungal infection at the top of my rule-out list. Be sure to look for lice as well.
Onchocerca is a parasite that lives under the skin and is transmitted by biting gnats. The literature shows that many horses are infected by Onchocerca, but only a minority of them actually show the allergic reaction that includes itchy, scaly skin. The belly, chest, face and neck are the most common areas to be affected. The disease seems worse in the summer, but can be found year-round. Onchocerca may migrate through the horse's body and lodge in the internal chambers of the eye. An ophthalmic exam can visualize these larvae swimming within the ocular fluid. Skin biopsies and "mince-preps" can be performed by your vet; the microfilarie are easily found.
Treatment of the microfilaria and larvae includes monthly oral ivermectin, usually repeated 2-4 times. A steroid may be necessary to decrease the horses immune response and mild flare-up from the dying parasites. The adult Onchocerca cannot be killed; it will continue to live within the ligament of the crest of the neck, and intermittent shed of larvae will cause occasional repeated symptoms. The treatment is used as needed during these episodes.
Ringworm is a fungal infection that spreads from horse to horse and can infect humans as well. Multiple small round lesions with hair missing from their centers is the typical presentation. Horses become very pruritic. Have your veterinarian do a fungal culture if you suspect this disease.
Answer: There are a number of opportunistic fungi that will seem to take over if given a chance on an open sore. Your veterinarian can culture the crusts and determine if there is also a bacterial component to the infection as well. Topical antifungal/antibacterial/steroid ointments are available that may help your horse's condition. Betadine shampoo may help the areas, but occasionally doesn't quite clear everything up. Consider an oral, long-term antihistamine to decrease his itchiness, and of course, look for the primary reason for the scratching.
Can hives predispose to the rainrot infection? The hives were obvious on his neck, but now he has rainrot everywhere, especially his cannon bones and belly.
Answer: Dermatophilosis, or "rainrot", is caused by the bacteria Dermatophilus congolensis. It is thought to live in a dormant state on some normal horses and proliferates on traumatized and moist skin. Trauma to the skin can be incited by biting flies, scratching, excessive moisture, or prior wounds.
Allergies to insects or pollens may predispose a horse to hives, which when mature and oozing serum, are a prime candidate for a dermatophilus infection. Because the bacteria can be carried by the horse, an onset of rainrot can occur within 24 hours. It is not surprising that your gelding showed symptoms only a few days after the hive episode. You might consider changing your therapy to a chlorhexadine or benzoyl peroxide shampoo, which are both drying and antibacterial. Use a large sponge to ensure that the skin on his belly and legs is reached.
In some cases, oral or injectable antibiotics improve the horses condition greatly. Of course, keeping moisture to a minimum is important, and remember that rain isn't the only source of damp skin and hair. Always scrape and towel dry your gelding, especially his legs and belly, after bathing or cooling him off.
Answer: Urticaria is a skin disease process of hives, swelling, and itching (pruritus). It can be caused by any number of allergens, including insects, pollens, sunlight, heat, or stress. It can be difficult to narrow down the exact inciting agent. In certain regions of the country mosquitoes are often the primary allergen. I have found that some horses improve when we move them to a different barn or environment, theoretically because they leave the offending allergen behind.
There is a blood-testing method available to identify allergens, but controversy abounds as to its true diagnostic value. Skin-bleb allergy testing such as is performed in humans and small animals has practical limitations due to the flight instinct of the horse, but may be available in your area. Antihistamines can be given long-term to diminish the inflammatory reaction and improve his comfort.
Consider having your veterinarian out to do a full exam that includes a long-term treatment plan. You may find that an accurate diagnosis allows a specific treatment protocol and ultimately a far less costly veterinary bill than treating by trial and error. Your veterinarian can also address whether herbal immune stimulants such as Echinacea are indicated in this case.
Answer: I see this on a number of horses, especially in the early spring, but some horses maintain this "scurf" on their legs year-round. The common name for this condition is "cannon crud", medically known as cannon keratosis. The cause is unknown, though it is speculated to be a hypersensitivity. (Make sure to rule out dermatophilus and ringworm however!)
Topical drying shampoos (with benzoyl peroxide or chlorhexidine), and topical glucocorticoids are helpful in decreasing the reactive crusts and hair loss. The literature reports Retin-A cream (tretenoin) as useful in removing the crusts and matted areas.
Question:
Have you heard of reaction to injections like this? Do you think the tail problem could have been related to the injection reactions?
Answer: Horses can certainly suffer from injection site reactions; occasionally silicone-coated needles are incriminated; switching to a non-coated needle controls the site lumps. Vaccines and other medications that are injected can be irritating to the skin or subcutaneous tissues, and bacteria can be pushed in at injection and create an abscess. Your mare sounds like she could have an allergic tendency. Her tail abscesses may have been created by the trauma of rubbing or of festering a splinter of wood or other foreign body.
Consider trying to identify the initial cause of the tail rubbing, and talk to your vet about trying silicone-less needles for all injections.
Answer: Because this is happening in all of your Pinto horses, you should look for a common cause such as a fungal infection or a photodermatitis. White areas on any breed of horse are more likely to become inflamed or burnt by sun exposure, and is one of the more common reasons for white area-specific scaling. Photoirritation can become so pronounced that the scales fulminate into open sores. Photosensitivity can also occur when the horses graze on weeds and plants that are toxic to the liver. Less likely are some seborrheic (flaky and crusty skin) disorders that are hereditary and should be considered if all of your Pintos are related.
The first step in treating these guys is to provide shade during the day to prevent excessive UV exposure. Light summer sheets would be ideal to give them good cover and still allow them outside during the day. Fly screens and masks for their faces will give some sun protection as well. Infant formulations of sunscreen can help prevent sunburn and irritation. If shade and sunscreen aren't sufficient to decrease the scaling, they may need a skin biopsy to further differentiate the cause.
Answer: Always rinse him completely after work; the sweat and salts that continue to contact his skin can be quite irritating and inflammatory. A thick sponge works well to get up in those tighter spots like his back legs. Don't forget the girth area as well. Dry those areas well, and try not to allow the "dregs" of bath water to drip from his legs and belly.
Consider using a cortisone spray or ointment in that area in conjunction with the antibacterial/fungal shampoo. This topical steroid may quiet the inflammation before it turns into raw spots. Never use a cortisone on an already open wound as it will decrease healing and could worsen any infection.
Answer: This poor guy sounds as if he suffers an awful case of insect hypersensitivity. The bumps and itching are an allergic process called urticaria. Treatment consists primarily of removing the insect contact, and secondarily of decreasing the allergic symptoms.
If you aren't on the property, consider moving him to a new area that is less insect infested, or one where he can be overseen by a responsible person. A fly-sheet, a darkened stall, fly sprays for him and insecticides for the environment are important stable managment techniques to help his discomfort. Your veterinarian may be able to prescribe a long-term course of an antihistamine such as hydroxyzine or pyrilamine to prevent the buggy flare-ups.
Recently, I have seen a podiatrist for a problem on my own feet and he said that no topical fungal treatment is effective (in humans). He cultured the problem that I had and gave me an oral medication. With this knowledge, why shouldn't the same course of treatment be recommended for the horse?
The affected area is quite extensive on his hind pasterns. I am not a sloppy horse keeper-I keep clean stalls and try to keep the fields mowed to hold down the dew in the grass and my horses are seen regularly by my vets. They are always quick to provide Tribrissen (SMZ) tabs when the horse gets cellulitis from the constant irritation. Your recommendation would be greatly appreciated.
Answer: Unfortunately, you and your horse have experienced the frustration of "scratches" and the multitude of treatment regimens that we all try, some with success, some without. It sounds as if you have attempted all of them, and I commend you for being aware of the need for good stable management to decrease the pastern condition. You might consider having a biopsy performed on his pasterns and affected skin in an effort to definitively identify the components of his dermatitis. Many times "scratches" is made up of a bacteria, a fungus, and an inflammatory or allergic response to the infection. Some horses with severe scratches benefit from oral antibiotics and oral anti-inflammatories. Oral antifungals are available, but rarely prescribed in horses, in part due to their expense as well as their potential to cause organ damage. Some fungal skin infections do become so deep-seated that the need for the oral medication is greater than the risks of the medication, however these cases should be confirmed with a biopsy.
I would suspect an allergic component in your gelding's condition given the chronicity of the disease. Your vet can tell you whether he might be a candidate for an immunostimulatory medication like EqStim, which may help his own body fight the constant infections. The best immune system booster is making sure that he is otherwise healthy and is on an excellent nutrition plan. Unfortunately, there are certain cases in which we never completely clear up pastern dermatitis, and we are left managing the flare-ups.
Answer: Great thinking! The added stress from exercise can in fact make an allergic reaction worse, or at least take longer to resolve. It is a good idea to rest your horse during and after an episode, regardless of whether they required medications to heal or not. Most horses will improve remarkably within 24 to 72 hours. Start them back to training slowly after the rest period.
Answer: Your mare sounds more ticklish than truly itchy from the water. It is possible that her skin is hypersensitive to the water, especially if she has been irritated by insects during the day, but without hives, swelling, or reddened skin I would lean more toward a basic dislike of the water! I have two clients who each have mares that detest water dripping onto their legs; they can have water sponged anywhere as long as their legs don't get wet. It sounds as if you have addressed other potentially allergic issues, so I would be inclined to try different ways to rinse her off. Try sponging her off or using a damp cloth instead of the hose, or consider not rinsing her every night. Good luck!
Do you know what could have been the cause? And is there anything I could give her; antihistamines? Or should I be cleaning the sores to prevent spreading? Or, is it not something that necessarily "spreads"?
Answer: Winter allergies can be due among other things, to molds, dust spores, and trapped moisture under a heavy winter hair coat. In Wyoming it may be difficult to bathe her in the middle of winter, but a thorough brushing every day may help alleviate some of the dander and dirt that can collect over the cold months. Pasture turnout, rather than stabling, can alleviate her symptoms, since the fresh air is healthier than a tight barn. (Having gone to college in Laramie I know all about the wind!)
Hopefully the discharge wasn't actually pus, which would suggest an infection, but actually serum. Serum is a component of blood, and is common when a hive "matures" and breaks, creating a small crust when it dries. A skin infection would be treated with Betadine solution and an oral antibiotic. A true bacterial or fungal infection could spread over her body and should be seen by your veterinarian. Consider an oral long-term antihistamine such as pyrilamine or hydroxyzine if the hives return this winter.
The problem seems worse during the hot summertime. I think this is a problem he has always had, because he has a scar near his tail, about 1/2 way down his buttocks. He had this scar when I purchased him.
Are some horses just prone to be tail-rubbers? His tail is beautiful and long, almost to the ground, but thin and broken at the top, from his tailbone up, where he rubs it.
I have tried all manner of creams, sprays, solutions, etc. to condition the tail and soothe it. I have washed it and conditioned it. I always rinse very well. Nothing seems to work.
Answer: If you made very sure that he is well dewormed, does not have external parasites or allergies, and does not have a bacterial or fungal infection of the skin on the tail, it may be that he has developed tail-rubbing as a bad habit. Try to minimize the areas available that he could rub against; fence posts, stall walls, trees. I have had some clients relocate their tail-rubbing horses to pastures with electric fence and no trees, and some have had to go as far as electrified wire on the favorite stall or barn wall. One horse would wait until he was in the trailer and then rub his tail madly the entire trip.
Consider a cortisone cream on the tail when he's itchy, and ensure that their are no insects causing him irritation when it is hot. Give him diversions to alleviate boredom, and consider a great big pasture that has fewer areas for rubbing.
Answer: Ringworm, a fungal skin infection, generally is self-limiting and resolves on it's own within months. If your gelding has had this problem for years, I would highly suggest a skin biopsy. Possible causes for these lesions would be an unusual form of ringworm, a parasite, an auto-immune disease, or a longstanding allergy.
Answer: The first thing that comes to mind when I hear of an itchy draft horse is the Chorioptes mite. It is a host-specific mite which does not affect people, but will move from one horse to another readily. This parasite causes intense itching, and seems to do best in the heavily haired area of the fetlocks and pasterns. Trimming the feathers will help fight a mite infestation, as will Ivermectin given three times at two week intervals. Topical miticides may be necessary in heavily infested horses. Chorioptes equi can be very difficult to fully eradicate from draft horses, and I would highly recommend working with a veterinarian who is familiar with these big guys.
Answer: This is a great dermatologic problem since there is no known cause for collagen granulomas. It is possible that they occur after a series of insect bites or other trauma. Some seem to appear for no reason. They cause the horse no pain or discomfort, but because they commonly occur under the saddle area, owners worry they will become open or sore. I rarely treat the collagen lumps that are not under the saddle or tack, and have seen some resolve on their own. I have had success with steroid injections made directly into the nodule to lessen the inflammatory response.
A skin biopsy can be performed, and may reveal the definitive cause of the nodules in your horse.
Answer: "Yearling warts" is a commonly seen dermatologic problem in young horses. The small warts are caused by a papilloma virus, which is spread by direct contact from one affected horse to another. Often an entire stable will suffer from the wart outbreak at one time. There is no proven treatment for these warts, and it is difficult to prevent their spread. The virus must run its normal course, and the warts will often resolve within a few weeks or months. Scraping or trying to remove the warts actually seems to make them last longer. They don't appear to be itchy or painful to the horse, but are found unsightly by the owner. The best treatment is "benign neglect"; keep the affected area clean and dry. Adding Neem oil or another softener is unlikely to change their progression.
Answer: Depigmentation of the skin (leukoderma) and/or hair (leukotrichia) can occur in any breed of horse, but Arabians seem to be one breed more often affected than others. Vitiligo (acquired depigmentation) occurs usually on the muzzle or around the eyes. There is no known cause for vitiligo, but it is thought to be hereditary. The faded areas are at risk for sunburn, and in some cases may be prone to skin cancers. Spotted leukotrichia is found in Arabians as well.
Mottled leukoderma can be found anywhere on the body, and appears to be secondary to previous skin trauma. Hypersensitivity to insect bites, sunburns, pressure sores, or contact irritants can leave the skin depigmented. Most often these spots are benign and may even repigment over time.
Hypothyroidism does result in dermatologic change including a rough dry haircoat, but I have not found any reference to leukoderma as a symptom. A skin biopsy of the affected areas may reveal a cause, though treatment attempts have not been very successful in restoring pigmentation.
Answer: When there are a multiple number of itchy horses on a farm, I always look for communicable disease such as lice, mites, or other external parasites, ringworm (a fungal infection), or internal parasitism. Sunburn or sensitivity, insect hypersensitivity, allergies to food, pollen, or dust are other things to consider. Fly sprays and dirty blankets and tack can irritate the skin and cause itching.
If all of these are normal, consider bathing your horses with a hypoallergenic shampoo that is oatmeal based or has a mild cortisone. Aveeno bath oil diluted 1:20 (water:Aveeno) may help, but test a small area on each horse first to ensure no allergic reactions.
During this process the Vet noted several dark colored nodules of various sizes on his penis. The Vet was very concerned and mentioned squamous cell carcinoma or sarcoids as two of the possibilities for this. (However, the skin is not ulcerated.) The vet told me that these nodules could cause irritation which would account for the gelding not keeping his penis tucked up in the sheath. I have not observed any other skin irregularities. The gelding seems okay otherwise.
I think due to the number and location of these nodules, a surgical solution probably isn't a practical option. If it is squamous cell carcinoma, what are the treatment options?
Answer: The first step is to biopsy the nodules and have a pathologist identify the actual cause. If the nodules are indeed cancerous, the appropriate treatment protocol can be followed. Squamous cell carcinoma and melanoma, especially in grey Arabians, are two common neoplasms, or tumors, found in the preputial and penile area. Surgical debulking (removing the majority of the obvious tumor), followed by oral or topical chemotherapeutics is a course often followed with cancerous masses. Cryotherapy is a method of debulking that involves localized freezing of the lesions once or multiple times.
Answer: There is a condition called telogen/anagen defluxion that can show up in stressed horses (change in weather, diet, environment...) as a loss of hair with no other abnormalities of the skin. The hair follicles actually become arrested in their growth (anagen) and shed (telogen) cycles, so instead of only a few hairs shedding at a time, all of the hairs fall out. No one is sure of an exact cause, but sometimes these defluxion horses become nearly bald. It is not painful, itchy, or otherwise uncomfortable unless the weather is cold or they suffer sunburn. The hair grows back in spontaneously over the next few months. Diagnosis can be made by your veterinarian.
Other diseases to consider include fungal infection, external parasites, sun sensitivity, or even just a new hair coat coming in.
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