Skin Health

Written by Briony Witherow MSc, BSc, RNutr.

Skin issues can often appear over the summer months (weather and insects often playing a role) and as we move through coat changes in the spring and autumn. This blog focusses on how we can promote skin health, how to manage suspected food allergens, and proactive prevention.

The most important factor for healthy skin is a correctly balanced diet.  Key nutrients to note with a known role for skin health are protein (amino acids), lipids, vitamins, and minerals (notably zinc, manganese, and vitamin B3).

Fundamental checklist for promoting skin health

• A balanced ration.
• Quality protein (ample amino acids such as lysine).

Skin Conditions

When it comes to skin conditions such as hives (also known as urticaria, a term often used to describe raised bumps on the skin) it can often be difficult to distinguish if the trigger has been inhaled, consumed, or come into direct contact with the skin.

When considering a potential cause, if the reaction is triggered by a food allergy, we would expect symptoms (hives) to be exhibited all over the body not just in a single location (which may be more indicative of a contact allergy).

While some skin conditions can be related to the diet, factors related to management and environment can often be to blame. For example, new bedding, insects, photosensitivity, equipment, or rugs recently washed with a new detergent, access to new pasture or environments. Like any problem, the more details recorded about the conditions when the issue first appeared, the easier it might be to isolate the cause.

It is worth noting that true feed allergies are thought to be rare in the horse and while commercial allergen specific antibody (IgE) based tests are available, research to date regarding the accuracy of these is inconclusive. False positive IgE serology can lead to overly restrictive and imbalanced rations in the long term. As such, the gold standard approach for a suspected dietary intolerance is an elimination diet.

Conducting an Elimination Diet

1. Remove all hard feeds and provide only ad lib forage/grazing for a minimum of four weeks.
2. Monitor symptoms.
3. If symptoms persist, where possible continue for a further few weeks and if possible narrow down environment and forage further (e.g., one environment and one forage source) provided this can be done safely, and without the horse losing too much weight and condition. If symptoms persist it may be worth investigating other causes in consultation with your vet.
4. Once symptoms are resolved, you can begin to re-introduce feeds gradually, one-by-one.

Additional Support

For those requiring additional support when faced with a potential allergic response, the following feed additions can help to moderate inflammatory response and therefore reduce severity of symptoms. For acute and severe reactions, always consult your vet in the first instance.

• A good supply of essential fatty acids linolenic acid (an omega 3 fatty acid) and linoleic acid (an omega 6 fatty acid). Examples include linseed (omega 3) and soya oil, (omega 6).
• Ensuring adequate antioxidant (e.g., vitamin E, C, selenium) provision can also help to support the body when it is facing any physiological stress (like inflammation caused by an allergen).

Preventative approach

For sensitive horses prone to reactions, promoting strong skin integrity (through providing a balanced ration) and providing support for the gut which plays an important role in immunity is recommended.  Keeping the gut healthy and providing support in the form of pre and probiotics may help to guard against allergies from the inside out. In addition to this, when making dietary (or management changes) try and make these one at a time and monitor response – this way you are able to isolate any unwanted reaction to a single change.