You may know of an older gelding at the barn that looks kind of shaggy and has weird fat deposits on his body. You often forget to ask his owner about it – or you may be too embarrassed to ask in the first place. What’s going on with that horse? Could it be Cushing’s disease?
It is good for every horse owner to know the basics about Cushing’s disease. More horses are becoming ‘pets’ long after they have retired from work and age-related diseases are on the rise. Cushing’s is considered a disease of older horses, as it happens mainly in horses over 18 years of age. But sometimes ‘youngsters’ can suffer – as young as 5 years of age. Let’s take a closer look at Cushing’s disease and how nutrition may play a role in keeping it at bay.
What is Cushing’s Disease?
Cushing’s disease is also known as hyperadrenocorticism. It can also happen in dogs and humans, but the disease process is markedly different. Cushing’s happens when the pituitary gland in the horse’s brain ‘miscommunicates’ with the adrenal glands. In return, the adrenal glands produce too much of a hormone called cortisol. You may have heard of cortisol as a “stress hormone.” In horses, this disease is better known as “pituitary pars intermedia dysfunction.”
Excess cortisol can cause a variety of problems in the body. Most of them we can easily identify in horses. Signs may include:
- Shaggy hair coat
- Incomplete shedding
- Delayed shedding
- Deposits of fat along the neck, topline and tail head
- Excess thirst
- Excess urination
- Chronic laminitis
- Obese body condition
- What does diet have to do with it?
Cushing’s disease in horses is not fully understood, damage to neurons in the brain can precipitate into a problem with the pituitary gland. According to Dr. Philip Johnson at the Western Veterinary Conference in 2012, “oxidative stress-mediated degeneration of dopaminergic neurons in the periventricular aspects of the hypothalamus appears to play a central role.”
So what does that mean in plain English? This means that oxidative stress is part of the reason that Cushing’s disease develops in some horses. Oxidative stress is caused by reactive oxygen and free radicals in the body. These “bandits” are created by a variety of things – from normal metabolism to stress and pollution. They in turn can damage cell membranes and DNA – leading to cell death. The body has a variety of ways that it can “cope” with free radicals. However, genetic mutations, certain disease states, stress, age and other factors can inhibit this – allowing for oxidative damage to take its toll.
While oxidative stress and how it damages the body is a very complex subject, the body uses a few things to combat it. Antioxidants from the diet are used in its fight against oxidative damage as well as certain antioxidant enzymes. If there aren’t enough in the body – oxidative damage can occur at a faster rate.
Could we prevent this oxidative damage that causes Cushing’s disease in horses? It is hard to say, and there is no scientific evidence yet that you can. However, improving your young or older horse’s diet by including antioxidant-rich foodstuffs, like flax and sea buckthorn berry may certainly help tip the scale in your horses’ favor.
Sea buckthorn contains a variety of bioactive antioxidants and minerals such as zinc and magnesium, which may be helpful in supporting animals with Cushing’s disease.
If you notice any of the aforementioned signs, talk to your veterinarian. Another condition, called Equine Metabolic Syndrome (Peripheral Cushing’s Syndrome) can also cause similar signs.
If your horse already suffers from Cushing’s or Equine Metabolic Syndrome, talk to your vet about using high-antioxidant foodstuffs as an adjunctive treatment or nutritional support.
Resources
(1)Huey-Chun Huang, et al., Inhibition of melanogenesis versus antioxidant properties of essential oil extracted from leaves of Vitex negundo Linn and chemical composition analysis by GC-MS Molecules. January 2012;17(4):3902-16.
(2)McFarlane, D. The Role of Oxidative Stress and Neurodegeneration in Equine Pituitary Pars Intermedia Dysfunction: A New Look at an Old (Horse) Disease. ACVIM Forum Proceedings. 2005.
(3)Johnson, P. Equine Cushing's Disease (Pituitary Pars Intermedia Dysfunction): Pathophysiology & Clinical Recognition (EQ9). Western Veterinary Conference Proceedings. 2012.
(4)Messer, N. Endocrine Disorders of the Horse. Western Veterinary Conference Proceedings. 2010.
Always consult with your veterinarian before starting a new medication, remedy or nutritional supplement. The information provided in this article is for educational purposes only – it is not intended to diagnose, treat or cure any disease process.
Omega-7 Fatty Acids
Omega-7 fatty acid, potent monosaturated fats, are less well known than other omegas but are very important for our health. Omega-7’s secret is out, as many biomedical researchers have found that its potent benefits overshadow those of omega-3.
Omega-7 has multifaceted benefits, which include:
Increases skin/coat health
- Boosts collagen production in skin
- Helps skin cells repair sun damage
- Enhances skin’s moisture content
Digestive support
- Improves mucous membrane function of the stomach and intestines
- Helps support mucous membrane repair
- Anti-inflammatory properties
Cardiovascular support
- Has been shown to improve blood lipid profiles
- Anti-inflammatory properties – smoothing inflamed arteries and veins
Diabetes, obesity and weight management
- Increases insulin sensitivity of bodily cells – improving insulin resistance
- May have a “signaling” function that helps the body control weight and fat reserves at the cellular level
Skin allergy, also known as allergic dermatitis, is a fairly common problem in horses. Some horses are seasonally affected while others suffer year-round. Sometimes their discomfort is so severe that they can no longer be ridden or easily handled. A few things need to be considered in diagnosis, treatment and prevention of allergic dermatitis symptoms. You may be surprised at the things that you can do at the barn to help manage or prevent symptoms.
What is Equine Allergic Dermatitis?
Equine Allergic Dermatitis is the skin’s reaction to an environmental irritant. Allergies are generally caused by the body’s over-reaction to a non-harmful substance. Common causes of allergy across species include pollen, molds and insect bites. Researchers are not completely sure why some allergies occur, but it could be due to genetics or a faulty immune system. In horses, hypersensitivity to fly and mosquito bites is usually to blame.
Symptoms
Signs can include hives - those itchy, raised bumps. Horses may kick at themselves and bite their skin – sometimes to the point where they bleed. Rubbing affected areas on fence posts or water buckets can also provide temporary relief but can severely damage the skin. Some of the “wheals” can resemble donuts – a raised ring of swelling and inflammation with a “pit” in the center. These poor horses are often irritable and can be difficult to ride.
Control and Prevention
The best way to prevent allergy flare-ups is to prevent the bites. Long-acting fly sprays (such as Freedom 45 Spot-On, from Star Horse Products NV) can be applied to fly sheets. Automated fly spray applicators should be considered for barn systems. Mosquito magnets should also be used in the barn and near the turnout paddocks. Stabling your horse during peak seasons and times of day can reduce the number of bites. Avoid turnout near sources of flies, such as cattle or manure piles. Severely affected horses may need veterinary treatment with corticosteroids.
Immune Support
It has been well-documented that supplementation with omega fatty acids can reduce allergic reactions to insect bites in horses.(1) These omega fatty acids provide essential support to the immune system and aid in the skin’s ability to heal itself. A great example of how omega fatty acid supplementation has healing and soothing powers is found in an 18- week study of horses with mosquito bite allergic dermatitis in Florida. The horses were supplemented with either high levels of omega-3 or with corn oil (high in omega-6) in a double-blinded crossover study. The horses showed the most improvement in their comfort level when on the diet high in omega-3. (2)
Plant-based supplements such as Seabuck 7 Equine provide a rich source of omega-3, omega-7 and omega-9 fatty acids. Additionally, the natural sea buckthorn berry in Seabuck 7 Equine contains other skin support compounds such as Vitamin E, flavonoids and carotenoids. Omega-7 is also an important component for proper skin healing and for maintaining elasticity.
Additionally, topical preparations of sea buckthorn berry (Seabuck 7 Skin Relief) can be helpful to soothe and aid healing of hives, insect bites and minor abrasions. If your horse suffers from allergic dermatitis, this is a must-have remedy for your grooming kit!
Resources
(1) Rashmir-Raven, Ann. Equine Dermatology: Allergic Dermatitis (EQ39). Western Veterinary Conference Proceedings. 2012.
(2) Friberg, C., Logas, D. Treatment of Culicoides Hypersensitive Horses with High Dose n-3 Fatty Acids: A Double-Blinded Crossover Study. Vet Dermatol. 1999;10(2):117-122.
Always consult with your veterinarian before starting a new medication, remedy or nutritional supplement. The information provided in this article is for educational purposes only – it is not intended to diagnose, treat or cure any disease process.
