How Does Cushing’s Disease Start?

Cushing’s Disease is also known as Pituitary Pars Intermedia Dysfunction (PPID) because it involves both the hypothalamus and the pituitary gland. However, I prefer to avoid the term PPID which focuses on the pituitary gland as the primary cause, which, is not exactly the case; PPID, like almost all other diseases, develop from a myriad of different factors that affect other organs as well. And most of those factors are caused by a domestic lifestyle.

The pituitary is a tiny little gland (its size belies its importance) located at the base of the brain behind the sphenoid sinus cavity. It’s about the size of a grape. Its job is to produce specific hormones in response to signals from the hypothalamus. The hypothalamus is another slightly larger gland just above the pituitary and is attached to it by a stalk.

The hypothalamus responds to a variety of internal and external signals to maintain homeostasis (balance) by stimulating the pituitary to produce important hormones. The hypothalamus is the major integrating link between the nervous system and the endocrine system. Therefore, body temperature, hunger, satiety, various emotions, motivation, pain, and stress, all have an effect on hormone production.

Instructed by the hypothalamus, the pituitary then regulates all other endocrine glands by releasing hormones directly into the blood stream to communicate with the thyroid, adrenal glands, thymus, ovaries, testicles, and the islets of Langerhans cells in the pancreas that produce insulin. It’s a sophisticated and incredibly complex system, that when healthy, serves the body well.

But in Cushing’s Disease, the pathways between the hypothalamus, the pituitary, and the adrenal glands are disrupted because the hypothalamus signals the pituitary to produce too much adrenocorticotropic hormone (ACTH) which causes the adrenal glands to produce an excess of cortisol. 

Why is Cortisol a Problem?

At normal levels, cortisol is an important part of the horse’s overall health. It helps a horse cope with stress, control inflammation, and regulate the immune system. Cortisol is a natural anti-inflammatory which is produced during any kind of physical pain or discomfort.

But the problem with cortisol begins when the levels don’t drop back down to normal as is often the case with our stressed-out domestic horses. The life of a domestic horse is not easy; most of them are caught up in a cycle of constant stress caused by high sugar diets, grass pastures, isolation, confinement, pain, inflammation, over-medicating, over-training, lack of exercise, abuse, and neglect. In states of chronic and prolonged stress, cortisol levels remain high for long periods of time. And it is these high levels of cortisol which starts the freight train of damage.

Aside from the effects of cortisol on the brain, it results in weight gain, insulin dysregulation, thyroid imbalances, tissue breakdown (catabolism) including hoof tissue, laminitis, a depressed immune system, muscle wasting, bone and joint weakness, and depression and anxiety.

The Dopamine Connection

Newer research has discovered that the disruption between the hypothalamus-pituitary pathway is actually because of a dopamine deficiency. Dopamine is a neurotransmitter that helps to regulate the pars intermedia (middle) portion of the pituitary gland and controls the over-production of its hormones. But some of the neurons (brain cells) which produce dopamine are degenerated and are therefore unable to produce adequate levels to control the pituitary hormones.

These uncontrolled pituitary hormones, including ACTH, run amok affecting other body functions. But aside from the hormone confusion the primary complication is that the pituitary begins to enlarge, and often forms an adenoma, i.e., a benign tumour, which is white to yellow in colour. Pituitary adenomas produce an abnormal production of ACTH (as well as other lesser-known hormones). This pituitary enlargement is thought to be the result of the dopamine deficiency causing the pituitary to secrete large unregulated quantities of ACTH which it is not hardwired to do at those levels. And so, just like any other overworked gland or organ, it begins to enlarge.

Now from a purely science point of view the primary cause of Equine Cushing’s disease is thought to be these damaged neurons that can no longer produce enough dopamine. But the mystery of why the dopamine neurons have been damaged in the first place has not been solved. At least not in the lab.

In the holistic model, however, we always look for the true and underlying cause of the imbalance rather than focussing just on the mechanics of the condition. Following the chemical trail often leads to a dead-end unless the objective is to design a new pharmaceutical.

And so, we must ask, how is it logically possible that so many senior horses have a pituitary tumour? This is beyond random. And why don’t as many horses also have skin cancer, a kidney tumour, or a muscle disease, or whatever…Why is it specifically a dopamine-ACTH problem? And what other purposes does dopamine have that the levels need to be so high that it burns out the neurons? Let’s see if we can connect the dots.

The Dopamine Lifestyle

Dopamine is a type of neurotransmitter that sends important signals from the brain to the body. It is important for motor skills, cognitive abilities, memory, and learning new things. It helps with focus and attention span and affects sleep patterns and social behaviours. It also plays a key role in the reward and motivation system by producing feelings of pleasure, as well as excitement like when something important is about to happen! Rewards resulting in pleasure is significant for horses since the biggest reward for a horse is sugar! Just like people.

Low levels of dopamine are known to cause lethargy, muscle stiffness, fatigue, apathy, and depression, all of which we so often see in our Cushing’s horses. A dopamine deficiency can also cause attention deficit, digestive problems, and weight gain.

But what’s really important regarding our horses is that dopamine production is affected by quality of sleep, excess weight or obesity, lack of exercise, stress, and a probiotic deficiency which affects the hindgut microbiome. So, we’ve got a lot more to work with other than just trying to artificially increase dopamine levels with medication.

Cushing’s Disease has everything to do with lifestyle, and the stressors of domestic living. Why else would it be an epidemic?

Conventional Treatment for Equine Cushing’s

The current medications for PPID act as a dopamine substitute to encourage the pituitary to suppress its hormone production. These medications do not however, extend longevity and some experts question how many horses actually improve their quality of life. Some horses seem to tolerate it, but we do know that the medications can cause multiple side effects including decreased appetite or anorexia, diarrhea, colic, fatigue, weight loss, skin problems, joint or muscle pain, and a fast heartbeat. Depression, anxiety, and behavioural changes are also common. Similar medications intended for people were removed from the U.S. market several years ago due to serious side-effects and safety concerns. Go natural…

Natural Health Program for Cushing’s Disease (PPID)

The majority, if not all, Cushing’s horses either have IR or some degree of sugar sensitivity or metabolic disorder. Therefore, diet, nutrition, exercise, and the reduction of stress levels are key. Herbal remedies and homeopathy complete the program.

Pro-Colon probiotics – ¼ tsp daily

A balanced microbiome is proven to be very important for a variety of health conditions and hormone imbalances. A healthy microbiome supports the intestinal immune system, maintains digestion and nutrient absorption, and aids leaky gut. 

Metabolism Drops, homeopathic – One dose (5-10 sprays) daily for 21 days or longer as needed.

This remedy is best used if the Cushing’s horse is overweight or has an excessive appetite. Supports normal blood sugar levels, maintains normal body weight, and normalizes appetite in overweight horses.

Vitamin B6 – 750 mg daily (= 1 tsp)

Nutritional support for hormone production, as well as thyroid and pituitary function. Supports mental health and energy levels.

HPA Balance herbal blend – 2-3 Tbsp daily

An herbal blend containing a proprietary blend of Ashwaghanda, Licorice Root, Chaste Berry, Kelp, and Raspberry Leaf to support horses with hormone imbalances. Promotes healthy adrenal and pituitary function. Maintains calm behaviour.

Performance Plus herbal blend – 2-3 Tbsp daily.

All all-natural blend of adaptogen herbs to maintain energy levels and vitality. Supports the endocrine system. Promotes hoof growth, normal metabolism, and a healthy immune system. Maintains a healthy nervous system. Chia seeds, Ashwaghanda, Siberian ginseng, and Spirulina. 

Vitex+Plus, homeopathic – One dose (5-10 sprays) daily

A proprietary formula containing homeopathic ACTH, Quercus Robar, and Chaste Berry. Promotes normal hair growth, shedding, body temperature, and energy levels. Supports pituitary health. 

Slow Feeders mimic natural grazing, help to regulate appetite, encourage weight loss, reduce stress, alleviate boredom, and contribute to general health and wellness.

Resolving Equine Metabolic Syndrome

Not only do we recognise that EMS is a serious epidemic and can be a challenging problem for many horse lovers, but we also know that people struggle to find the right care for their horses. Every day we hear from concerned horse owners who have run out of options and don’t know what else to try. Or whose horses have stopped progressing.

With a deeper understanding and extensive experience of the underlying causes of Equine Cushing’s Disease we offer a completely holistic approach where you will learn how to feed your horse, how to apply therapeutic nutrition, and use specific supplement recommendations. This course includes exclusive information to support EMS, IR, PPID, and PSSM with strategies for prevention, recovery, and maintenance of good health.

We consistently hear that horses whose owners have implemented natural programs based on solid information and practical experience have more energy, less depression, normal haircoats, a stronger immune system, optimum well-being, and healthier hooves.

This is a self-paced short course available at any time.

Sign Up Here!

“The difference in my horses from just the few changes implemented from this EMS course is unbelievable.”

…Jo W. Australia

Zak Did It!

Zak was a 22-year-old Arab gelding living in Calgary, Alberta. His story came to me when he was 16 years-old when he was already showing the visible signs of Insulin Resistance and Cushing’s disease. His owner, Bernice had tried a couple of health products for him, including Chaste Berry, but did not have much success with resolving his health issues.

Zak was at least 100 pounds overweight with fat pads around his tail head and his shoulders and a pot belly. He had a long coat that got curly when he was wet (he looked like a buffalo), was sweating easily, his eyes were runny and dull looking, and he was depressed with very low energy levels. Needless to say, Zak loved food. His diet consisted of full-time grass pasture, 1-2 cups of crushed oats, four to five carrots per day, and a molasses-based vitamin and mineral mix.

The first step with Zak was diet. We switched him from grass pasture to grass hay and eliminated his oats, his carrots, and his vitamin mix. Then we added vitamin B6 and vitamin B12 to support his digestion and his metabolism, as well as the Metabolism Drops to maintain his sugar and insulin levels. Zak also needed digestive support since his high sugar diet combined with his sluggish metabolism had resulted in a leaky gut from the excess fermentation of carbohydrates. Therefore, his program included the Pro-Colon probiotics and Pro-Dygest herbal blend for cleansing and detoxification.

Zak’s first response to his new lifestyle was gradual but steady weight loss followed by an increase in energy. His shedding also improved but he was still sweating too easily, his energy levels were inconsistent, and he experienced some depression. So, we focused on his next layer which was his pituitary and thyroid function; the long years of excess weight and high dietary sugars had taken its toll on his hormones. So, Zak was put on the HPA Herbal Blend and Performance+Plus herbal blends to support the endocrine system, strengthen his vitality, and aid his immune system.

Exercise was important too. Throughout Zak’s entire journey of recovery, Bernice continued to ride him at least four to five times per week even if his activities were kept to a walk. She often stated that she would feel terribly guilty especially on days when he was so tired and depressed. But she knew that his exercise program was a critical part of his recovery.

Zak’s progress continued and he felt happier and healthier with every step. Bernice and I were both over the moon. And we were pretty sure that Zak was too. Not only did he regain his health but within a couple of seasons Zak even grew a normal coat and no longer looked like a buffalo. In fact, he didn’t even look like the same horse!

Many, many kudos to Bernice who was a very committed horse owner. Every morning she told Zak that he was going to become a healthy horse again. And so, he did.

      Before                                                                                                         After

Committing to our horses’ health is a necessary ingredient if our horses are to truly recover from their domestic health conditions and feel spectacular again.