The Horse:Your Guide To Equine Health Care provides monthly equine health care information to horse owners, breeders, veterinarians, barn/farm managers, trainer/riding instructors, and others involved in the hands-on care of the horse.
Issue link: https://thehorse.epubxp.com/i/821826
17 June 2017 THE HORSE TheHorse.com ■ Ectoparasites, such as lice and ticks (the latter of which can transmit Lyme disease); ■ Abnormal growths such as warts, sar- coids, melanomas, or aural plaques; ■ Body condition changes; and more. Soap doesn't need to be a staple when bathing and grooming. Soap itself is a chemical produced by mixing some sort of fat (vegetable oil, rendered beef tallow, coconut oil) with a base (such as sodium hydroxide) to create a salt—a process called saponification. Consider, too, that many products marketed as soaps or shampoos contain ingredients that aren't good-old-fashioned saponified fats. Ponder the following ingredients in some popular equine shampoos: ■ Water (also called aqua or eau); ■ Sodium lauryl sulfate, a detergent that produces lather and is known to cause skin irritation in humans; ■ Cocamidopropyl betaine, a coconut- derived foaming agent; ■ Sodium chloride or table salt; ■ Cocamide MEA, a coconut-derived product mixed with ethanolamides used to increase foaming; ■ Glycol distearate, which acts as a chemical emollient to reduce moisture evaporation from skin; ■ Propylene glycol for attracting water to give skin a supple look; ■ Fragrance (parfum), which contains undisclosed ingredients considered "trade secrets" by the FDA; ■ The preservatives methylchloroisothia- zolinone and/or methylisothiazolinone that possess antibacterial and antifun- gal effects and might irritate the skin in high concentrations; and ■ Butylphenyl methylpropional, a syn- thetic fragrance that's been linked to allergic reactions and skin irritation in humans. Using such products on occasion can certainly help your horse achieve that squeaky-clean look and feeling and remove debris, caked-on dirt, and even flakes of dry skin. Overuse (the definition of which will vary from horse to horse), however, strips the skin of its normal, healthy microbial populations as well as natural oils, primarily sebum. Instead of leaving the skin and coat clean, soft, and smooth, some horses begin showing signs of flaking, dandruff, and pruritis (itchiness). For comparison, think about how tight, dry, and itchy your own skin can feel after a long, hot, soapy shower. Further, soaps and their "extras" can cause skin irritation or even a contact dermatitis or allergic reaction resulting in hives. Being itchy, horses will find things to scratch themselves on, potentially damaging the skin further and allowing pathogenic organisms or even the once "healthy" organisms colonizing the skin to cause disease. "We often see dermatitis associated with Staphylococcus and Dermatophilus bacterial infections, both associated with overwashing and either destroying the protective flora or causing overgrowth of normal flora," says Bidwell. "Owners of- ten think there is a fungal component, but typically these skin issues are associated with Gram- positive bacteria, not fungi." Skin lesions are uncomfortable and can contribute to lost training or competition days. Further, depending on the severity and location, lesions can also preclude certain medical procedures from being performed. You might need to postpone joint injections, epidural analgesia, and acupuncture treatments if the skin is in bad condition. "Infections can spread quickly," says Bidwell. "In some cases, infections can be severe, causing cellulitis, which is a serious bacterial infection of the skin and associated tissues that can cause intense swelling and lameness. Prompt veterinary attention in these cases is warranted." One simple way to avoid infections is to minimize bathing with soaps and to dry a horse thoroughly following a bath. Constant moisture alone can still irritate skin, setting it up for infection. Further reason to make sure your horse is com- pletely dry before putting him up post- rinse or -bath is that, again, hair plays an important role in thermoregulation and can't do its job well when wet. Overwashing can destroy the skin's protective flora and allow bacteria to invade. SHAWN HAMILTON Nutrition's Role in Coat Health Researchers have discovered that nutrients such as the B vita- min biotin benefit human hair and skin. In horses, studies on biotin have only been performed with regard to the hoof, says Kathleen Crandell, PhD, an equine nutrition- ist for Kentucky Equine Research, in Versailles, Kentucky. "One of those studies, how- ever, anecdotally mentioned an improvement in coat quality when horses were supplemented with biotin," she says. The "tried and true" coat sup- plement over the centuries has been flax (linseed), says Crandell. The oil in flaxseed contains plenty of the "good" omega-3 fatty acid alpha-linolenic acid (ALA), as well as the more inflammatory omega-6 fatty acids, but in a lesser quantity. The body can convert ALA into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both of which are found in fish oil—hence, why many owners use this as a supplement for their horses' skin and coat. "Although there are no pub- lished research studies in horses on the impact of omega-3 fatty acid supplementation on skin and coat quality, fish oil has been found to be particularly helpful for treatment of skin conditions," says Crandell. "Practically speaking, few owners and trainers would (say) that a horse's coat does not improve with fat supplementation, be it corn oil, fish oil, flaxseed, or other ingredients with relatively high amounts of fat, such as full- fat soy that, according to studies involving subjective outcomes, improves coat quality. In the case of full-fat soy, it is probably the fat for the skin and the methionine for the hair in the soy that elicits the beneficial effects." Crandell cautions owners to add fat/oil to equine diets slowly and to not exceed 1 g per kilo- gram of body weight or the level that has a negative impact on the horse's feed consumption. —Stacey Oke, DVM, MSc