Few horse owners escape having to deal with the issue of itch. It is probably the most common dermatologic complaint. Itch is distressing to the horse, often causing significant trauma to the skin from scratching. The tail base, mane/neck, face and belly are most commonly involved, but itch can strike anywhere on the body.
CAUSES OF ITCH
Itch is an interesting sensation. It is closely related to pain; the nerves carrying the itch signal share the same pathways to the spinal cord and brain as pain messages do. Some of the same agents that block pain, like local anesthetics or plant-based blocks like capsaicin can also block itching.
The reflex reaction to pain is very different from itch. Pain causes the horse to want to withdraw and protect the area, while itch triggers the same reaction as it does in us – the intense desire to scratch. It has been suggested that itching evolved as a protection against attacks from insects or other irritants. The fact that receptors carrying sensations that cause itching are only found in the surface layers of the skin supports this idea.
A wide variety of things may cause itching. Most common are inflammatory or allergic reactions to insects, parasites, infections (especially fungal) or other triggers. Hives may itch. Excessive skin dryness or scab healing may cause itching. Rarely, nerve damage, liver disease, kidney disease or pregnancy may be a cause.
THE ITCH-SCRATCH CYCLE
Scratching often relieves itch by providing another, mildly painful sensation that blocks the itch impulses. Sometimes, the itching and scratching deteriorates into a self-perpetuating cycle. Vigorous scratching produces skin damage and inflammation that itself can cause the itching to continue even if the original cause is gone. Suffering horses need treatment to break the cycle.
Eliminating itching first requires identification and removal of the trigger, if it is still present. Beyond this, topical treatment of irritated or traumatized skin can ease ongoing itching and promote healing even if an itch-scratch cycle has become established. Systemic therapy with antihistamines or corticosteroids is rarely indicated.
Multiple herbal options are available for topical treatment. Aloe Vera and chickweed have antihistamine properties. Both are also generally anti-inflammatory and emollient/soothing. Chamomile is anti-inflammatory, antimicrobial and may have some mild anesthetic effects. Arnica is a very potent local anesthetic. Calendula is anti-inflammatory and mildly antimicrobial. Thyme is primarily antimicrobial with insect repellant potential. Tea tree essential oil is a potent antimicrobial and insect repellant. Other potential topical anti-inflammatories include elderberry and comfrey. White Willow is also anti-inflammatory and particularly effective against itch.
Regardless of how you decide to treat topically, be sure to keep the area clean by gently cleansing with a nondrying shampoo and cool water on a daily basis. Observe carefully for any signs of worsening inflammation such as swelling, heat, drainage, pain or worsening itch, since irritated skin may develop sensitivity to topical agents over time.
For details on pharmaceutical topicals to treat itch, consult with your veterinarian. Potential ingredients include corticosteroids, local anesthetics, topical antihistamines and antibiotics or antifungals for any associated infection.
Eleanor Kellon, VMD, is an established authority in the field of equine nutrition for over 30 years. She formerly served as Veterinary Editor for 'Horse Journal' and John Lyons' 'Perfect Horse' and is owner of Equine Nutritional Solutions, a thriving private practice and the author of many best-selling books.
Dr. Kellon currently serves as the Staff Veterinary Specialist for Uckele Health & Nutrition which was founded in 1962. They have been a trusted leader in the research, formulation, development and manufacture of quality nutritional supplements. The Uckele team creates balanced nutritional supplements to support optimal health and performance at the highest level. http://www.uckele.com