Chat with us, powered by LiveChat

Stymied by Scratches?

by Dr Clair Thunes PhD Nutrition
Consulting Nutritionist for EnviroEquine & PET
[eeb_email email=”” display=”” extra_attrs=”target=’_blank'”]

If you have been around horses for a while you have likely come face-to-face with dry crusty scabs on the back of your horse’s pasterns or perhaps some nasty looking crud on his cannon bones? You are not alone. Scratches or mud fever (correctly named equine pastern dermatitis), those crusty scabs on the pasterns, is a common affliction and does not appear to discriminate as to the horses it appears on. Similarly cannon crud, which is actually a form of keratosis or seborrhea, is also common.

What causes these conditions?

Equine pastern dermatitis (EPD) comes in several forms from the early stage dry scabs (scratches) that may be itchy and painful through a more serious form where the skin is breaking down, there is inflammation, hair is lost and a greasy exudate is formed. Hence the name grease heal. In its most serious form EPD results in clusters of grape like nodules which result from a thickening and scaling of the skin. Most commonly EPD is caused by bacterial infection causing a folliculitis.

The cause of cannon keratosis is not well understood but it is not a fungus and it is not caused by geldings that urinate on themselves. The condition is just as common in mares. For some reason the skin on the cannon bone generates too many cells that results in build-up. Often this is slightly oily. Similar cases of seborrhea occur on the ears, elbows and hocks.


Many owners are able to deal with the early stages of EPD themselves by clipping the hair around the pastern, and using a topical antibacterial scrub followed by a cream or salve such as EnviroEquine’s Fungicide Plus or CocoTeaSalve. Fungicide Plus contains colloidal sulfur as an antifungal and natural vitamin E from camelina oil that helps strengthen skin. CocoTeaSalve combines fatty acids from coconut to condition the skin as well as the antibacterial properties of tea tree oil.

Keeping the pastern area clean and dry is vital. In fact overzealous washing of legs is a major contributing factor in EPD because the sensitive skin on the back of the pastern will crack if exposed to frequent wetting and drying. Once dried, legs can be wrapped if necessary to keep the area dry while healing.

If these initial treatments fail to do the trick and the EPD becomes persistent it is recommended that a veterinarian look at the horse because there can be more serious causes. For example the issue may be caused by contact allergies, exposure to UV light causing photosensitization which may be due to kidney problems, chorioptic mange, or in some breeds it may be chronic progressive lymphedema. These conditions may require different treatment strategies.

Additionally there is the risk that these lesions, no matter the cause, may lead to another condition, cellulitis. Cellulitis results when the underlying tissue below the skin becomes infected. Infected legs become suddenly swollen, hot and painful to touch. In severe cases the swelling may travel up the leg and the horse may develop a fever. Cellulitis should always be treated by your veterinarian as life threatening complications can result in a very short period of time.

When dealing with cannon keratosis there is the temptation to vigorously work to remove the build-up of skin cells. But care should be taken not to damage the underlying skin as this may result in points of entry for bacteria and a skin infection. Light currying and regular grooming to remove dirt and sweat are important especially for horse that regularly wear boots or bandages when worked. Application of mild shampoo such as EnviroEquine Shampoo Plus once or twice a week may also be beneficial in addition to a barrier cream containing sulfur such as EnviroEquine Fungicide Plus.

Fungicide Plus and OmegaBalance helped heal an incredibly stubborn case of chronic scratches. I tried just about everything to clear up Enzi's chronic scratches and nothing worked...until I started using the Fungicide Plus and OmegaBalance. Honestly astonished with these results. I can't recommend these products enough.

Carolynne S


As the old saying goes “an ounce of prevention is better than a pound of cure”. While prevention may not be possible there are things you can do to reduce the risk of developing these two conditions. Good grooming and careful hygiene are important. Providing dry areas to stand, clean stalls, clean boots and wraps, and keeping leg washing to a minimum go a long way to help. So can feeding a correctly balanced diet.

Providing a source of essential fatty acids helps improve coat quality reducing dry skin. Dry skin is more likely to be flakey and at greater risk of cracking. Both the EnviroEquine OmegaBalance and EveryDayBalance products provide a plentiful source of omega-3 fatty acids that not only promote skin and coat quality but also help support a healthy inflammatory response just in case your horse does develop EPD.

Zinc is a trace mineral that is vital for strong epidermal tissue. In people, 6 percent of the bodies zinc is stored in the dermis and epidermis where it helps stabilize cell membranes. Zinc is an essential cofactor for a number of metalloenzymes including metallothioinien (MT). When skin is damaged, MT stimulates basal keratinocytes which help give skin its strength and flexibility. Therefore diets low in zinc may reduce tissue healing and skin’s ability to resist damage.

A number of the EnviroEquine supplements provide supplemental sources of zinc, including GastroBalance, GastroBalancePlus and EveryDayBalance. The zinc methionine, a form of zinc complexed to an amino acid, found in the GastroBalance Plus and EveryDayBalance is research proven to support epithelial tissue health and immune function.


While sometimes scratches and cannon crud will occur despite everything you do, there are steps that you can take to both reduce the likelihood of their occurrence, and to speed recovery should they occur. EnviroEquine provides a full range of products in the form of oral supplements as well as topical products to insure that you are armed with a full toolkit to help maintain and support your horse’s skin and coat health.

Consulting Nutritionist for EnviroEquine Dr. Clair Thunes is passionate about her profession—one that she decided upon at the age of 14. After earning a Bachelor of Science with Honors from Edinburgh University, and a Master of Science in Animal Science and a PhD in Nutrition from the University of California, Davis, Dr. Thunes went on to found Summit Equine Nutrition LLC an independent consulting company in 2007. An experienced nutritionist and accomplished scientist, Dr. Thunes understands the vital role that nutrition plays in managing horses today. Most importantly, she believes in making nutrition accessible to everyone and removes the guesswork so that owners have the peace of mind that their horse’s diets are optimal for maximum health and peak performance.  Her clients include all horses from competitors at the 2016 Rio Olympics to retired pasture friends, mules and miniature donkeys. She writes a weekly online commentary for and her nutrition articles have been published in noted publications including: The Horse, Equine Wellness, Trail Blazer, Horse & Rider and The Horse Report. Besides consulting she teaches equine nutrition and equine exercise physiology in the Animal Science Department at UC Davis and equine health at Cosumnes River College.  Clair continues to be involved with The United States Pony Clubs, Inc. and she is currently the Regional Supervisor for the Sierra Pacific Region.