Equine Cushing’s Disease, medically recognised as Pituitary Pars Intermedia Dysfunction (PPID), is one of the most common equine disorders affecting horses, particularly horses over the age of 15, which has no medically approved cure.
Cushing's in horses has a unique set of characteristics, symptoms, and treatments that set it apart from Cushing's experienced by humans and other animal species. Understanding these aspects is essential for the proper care and management of Cushing affected horses.
In this article, we will explore the causes of Equine Cushing's Disease, try to understand the commonly observed symptoms, and discuss the variety of treatment options available. Additionally, we will highlight the recognised benefits of a new complementary treatment method that has been shown to aid in the management of horses with this condition.
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PPID primarily affects horses over the age of 10*
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PPID occurs in up to 21.2% of horses aged 15 years older*
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63% of horses with PPID are treated medically*
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Of horses with PPID, 43% report a prevalence of Laminitis*
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There remains no clinical cure for PPID
What is Equine Cushing’s Disease (ECD or PPID)?
Equine Cushing’s Disease (ECD) is an age-related endocrine disorder caused by dysfunction of the pituitary gland, specifically the part known as the Pars Intermedia. This region of the pituitary gland plays a critical role in regulating the production of hormones that control a horse’s metabolic processes.
In horses with PPID, the Pars Intermedia becomes hyperactive, often due to a lack of dopamine, a neurotransmitter that typically prevents hormone production. When dopamine levels drop, the pituitary gland starts to overproduce certain hormones, most notably adrenocorticotropic hormone (ACTH). This hormone imbalance affects various bodily functions, particularly metabolism and immune response, leading to a large range of clinical signs and symptoms - including increasing the risk of laminitis.
Cushings primarily affects older horses, typically those over the age of 15, although younger horses can develop the condition as well. It has been shown in studies* that up to 30% of horses over the age of 20 may suffer from Cushing's, making it a critical concern for horse owners and veterinarians alike.
Cushings in Sports Horses
Sports horses and competing horses can also suffer from the condition which will reduce performances due to a reduction in the animals energy levels strength and overall endurance. Seen across many disciplines at all levels including dressage, 3-day eventing, showjumping, polo or barrel racing - being aware of the symptoms of PPID can increase the likelihood in detected any signs early.
Pergolide, the main medicine used to treat Cushings Disease, is not permitted in competition horses and also requires a ‘withdrawn period’ where the medication cannot be administered for a period time before competing – this makes managing the condition even more crucial in competing animals.
Understanding the Pituitary Gland
Before we look into the specifics of Cushing's Disease, it is helpful to understand the role of the pituitary gland. Located at the base of the horses brain, the pituitary gland is often referred to as the "master gland" because it regulates many of the body's vital functions by releasing hormones.
The pituitary gland is divided into several parts, including the anterior lobe, intermediate lobe (Pars Intermedia), and posterior lobe. In horses with PPID, the intermediate lobe becomes overactive, leading to the release of excess hormones. These hormones then impact the horse’s entire system, causing the signs and symptoms of the disease.
10 Most Common Symptoms of Equine Cushing's Disease
Horses with PPID display a wide variety of symptoms, many of which are subtle in the early stages of the disease but become more pronounced and obvious as the condition progresses.
Recognising these symptoms early can help ensure timely diagnosis and treatment, improving the horse’s quality of life and the ability to manage the condition before further complications occur.
Let’s take a look art 10 of the most common symptoms to look our for:
1) Abnormal Hair Growth
One of the hallmark signs of Cushing’s in horses is hirsutism, abnormal hair growth. Horses with PPID often develop a long, thick, and curly coat that doesn’t shed normally during warmer months. This can lead to the horse overheating, especially in the summer, and is one of the most recognisable signs of advanced (more severe) PPID. Some horses with PPID may also show regionalised hair growth changes, such as delayed shedding or patches of long hair in specific areas of their coat.
2) Excessive Sweating
Excessive or abnormal sweating, sometimes referred to as hyperhidrosis, is another common symptom in horses with Cushings. This can even occur in colder weather or during long periods of rest, and is often directly related to the abnormal hair growth, as the horses thick coat traps heat generated by the body.
3) Weight Loss and Muscle Wasting
Despite an increased appetite in some cases, horses with PPID may experience visible weight loss and muscle wasting, particularly along their top line and hindquarters. This is due to the altered metabolism and the breakdown of proteins in the horses body. Muscle atrophy is a significant concern for horses with Cushings, as it can impact their overall mobility and strength levels.
4) Reduced Energy Levels
A lack of energy is frequently seen in horses with Cushing’s Disease. Owners may notice that their horse seems less interested in exercise, slower to respond, or more prone to fatigue during activities that were previously easy for them.
5) Laminitis
Perhaps the most dangerous and life-threatening symptom associated with PPID is laminitis, a painful and potentially debilitating condition caused by inflammation of the horses laminae, found in the hoof.
Horses with Cushing's are at a much higher risk for recurrent bouts of laminitis, often triggered by the hormonal imbalances caused by the disease. In some cases, laminitis may be the first sign that prompts investigation into a diagnosis of PPID.
6) Increased Thirst and Urination
Polydipsia (excessive thirst) and polyuria (frequent urination) can be common symptoms of PPID. These signs occur as a result of hormonal imbalances that affect the horse’s kidney function. Owners may notice that their horse is drinking much more water than usual and urinating more frequently.
7) Abnormal Fat Deposits
Some horses with Cushings may develop abnormal fat deposits in specific areas of their body, such as above the eyes or along the neck. These fat deposits are caused by hormonal changes that affect fat metabolism and storage.
8) Recurrent Infections
The immune system of horses with PPID is often compromised, making them more susceptible to recurrent infections. This can include skin infections, respiratory issues, or delayed healing of wounds and sores. A weakened immune response is a significant concern for horses with PPID, as it increases their risk for many other health complications including hoof issues.
9) Infertility and Reproductive Issues
In breeding mares, PPID can lead to an increased risk of infertility. Stallions may also experience a reduced libido or other reproductive issues as a result of the hormonal imbalances caused by the disease.
10) Behavioural Changes
Finally, some horses with Cushing’s may exhibit significant and obvious behavioural changes, such as increased irritability, depression, or changes in their overall temperament. These changes can often be subtle but are important to note as part of a comprehensive assessment of the horse's overall happiness, health and wellbeing.
Causes of Equine Cushing’s Disease
The exact cause of Equine Cushing’s Disease is still not fully understood, but it is largely believed to be related to age-related degeneration of the nerves that regulate the pituitary gland, particularly those involved in the production of dopamine. The condition can be closely likened to Parkinson's Disease in humans.
As horses age, the neuron's responsible for producing dopamine in their brain are thought to deteriorate. Dopamine acts as an inhibitory signal to the pituitary gland’s Pars Intermedia, so when dopamine levels decline, the Pars Intermedia becomes overactive. This leads to the excessive production of ACTH and other hormones, which, in turn, causes Cushing’s.
Other contributing factors may include the genetics of the animal, oxidative stress, and chronic inflammation - although more research is needed to fully understand the underlying mechanisms of the disease.
In recent years Equine Cushing’s disease is becoming more common, thought to directly relate to the fact that horses are living longer and as more research is being carried out on PPID due to it’s direct link to laminitis.
Diagnosing Equine Cushing’s Disease
If Cushing’s is suspected, a veterinarian is required. They will typically perform diagnostic tests to confirm the diagnosis. The most common test measures the levels of a certain hormone in the horse’s blood, so a blood test will be required on first inspection.
Horses with PPID will often show to have elevated levels of the hormone ACTH. In healthy horses, ACTH levels naturally vary with the seasons, peaking during the autumn months of August, September, and October. This period is ideal for testing for Equine Cushing's disease, as affected horses show an exaggerated seasonal increase in ACTH levels, leading to significantly higher levels than those seen in healthy horses.
When establishing the correct diagnosis for your horse, your vet will likely ask you about any ‘non-clinical’ signs you have noticed; such as hair coat changes or changes in their mobility levels, however, laboratory diagnosis will be vital.
Another diagnostic option is called the “TRH (thyrotropin-releasing hormone) stimulation test”, which involves administering a small amount of a hormone and then measuring the horse’s response. Horses with PPID will have an exaggerated response to TRH, which helps to confirm the diagnosis.
It is also important to rule out other conditions that could cause similar symptoms, such as hypothyroidism or metabolic syndrome, as these conditions can sometimes mimic the signs of PPID.
Either way, as this article stresses, suspected PPID is a medical emergency and requires immediate attention.
Treatments for Equine Cushing’s Disease
While there is no cure for Equine Cushing’s disease, there are several successful treatment options that can help manage the symptoms long term and improve the quality of life for affected horses. Treatment typically involves a combination of medical management, supportive and holistic care, and lifestyle adjustments.
We take a closer look at some of the most commonly applied treatments:
1) Pergolide (medication prescribed by the vet)
The most widely used and effective medical treatment for PPID is Pergolide, a dopamine agonist that helps to restore dopamine levels in the brain. By increasing dopamine activity, Pergolide helps to inhibit the overproduction of hormones by the pituitary gland, thereby reducing the clinical signs of the disease.
Pergolide is considered by the medical community as the ‘gold standard’ of treatment for PPID yet statistics following studies of the effectiveness of Peroglide indicate that only 70% of horses experience success from the drug.
Some horses experience significant side effects such as reduced appetite and severe weight loss which then leads to anorexia. In some studies *32% of horse administered Pergolide then suffered from Anorexia. In these studies almost all horses administered the drug showed higher levels of lethargy, particularly during the initial phase of treatment.
2) Dietary Management
Proper control of the horses diet is crucial for horses with signs of Cushings, particularly those at risk of laminitis. Horses with PPID should be fed a diet that is extremely low in sugar and starch to help reduce the risk of developing laminitis and support overall metabolic health.
In most cases; if your horse develops early signs of PPID then an immediate alteration to the horses diet and supplement intake are required.
High-quality forage, such as grass hay, should form the basis of the horse’s diet, and concentrates or grain should be limited (or removed completely).
Owners may also want to consider supplements that support immune function, joint health, and coat condition, as horses with PPID often have compromised systems in these areas. Limiting pasture time will also be an important step.
Consult your vet if you are unsure on what would best suit your horse, and remember that every horse is different.
3) Exercise and Weight Management
Maintaining a healthy body weight and promoting regular fitness and exercise training are important components of managing Cushings. Obesity can exacerbate the symptoms of the disease and once again increase the risk of laminitis, so ensuring that the horse maintains their proper body weight is essential.
For horses with muscle wasting or reduced energy levels, a light to moderate exercise regime can help improve muscle tone and their overall fitness levels. However, exercise should always be tailored to the horse’s individual needs and abilities.
4) Laminitis Management
Due to the increased risk of laminitis in horses with PPID, ‘laminitis management’ is a critical aspect of ongoing treatment. This may involve working closely with a farrier to ensure proper hoof care, using supportive boots or pads, and providing a variety of pain relief when necessary.
In some cases, horses with recurrent laminitis may require more aggressive management strategies, including specialised shoeing, dietary changes, and medication to control inflammation.
5) Holistic and Natural Management
Many horse owners are now resorting to a variety of holistic approaches when managing a horse with PPID. This includes acupressure to help with hormone regulation, pain management and blood circulation.
A herb known as Chaste tree berries (Vitex agnus-castus or Monk’s pepper) is gaining popularity for its immune stimulating properties. It is worth noting that this herb merely masks the symptoms.
Rosehips, Turmeric, Green Tea, Grape Seed and Hawthorn are also rich sources of natural anti-oxidants; with links to dopamine production and
6) Regular Veterinary Check-ups
Given the progressive nature of PPID, regular veterinary check-ups are essential to monitor the horse’s condition and adjust treatments as needed. Blood tests to measure ACTH levels can be taken to ensure that the disease is being adequately controlled.
Vets may also recommend routine dental care, vaccination, and deworming schedules to help support the horse’s overall health, as horses with PPID are more susceptible to infections and other health issues.
7) Advanced Bio-Resonance Therapy for Cushing’s
One innovative and non-invasive complementary option for horses with PPID is the use of EQU StreamZ Horse Bands. These highly acclaimed therapy bands are designed to be worn around the horse’s legs and be used alongside and in conjunction with other PPID treatments and therapies.
Research and anecdotal evidence suggest that EQU StreamZ Horse Bands can be beneficial to horses with PPID, making them a valuable addition to the management of horses with the disease. While these bands are not a replacement for medical treatments like Pergolide, they can provide additional support in managing the symptoms of PPID, particularly in terms of improving mobility and comfort and are suitable alongside all other alternative treatments and therapies.
The horse’s immune response is the way the body defends itself against substances it sees as harmful or foreign. When the bodies immune response kicks in, the immune system recognises ‘a change in conditions’ and reacts to this. Because of this some horses with Cushing’s, when first wearing StreamZ technology, have reported an adverse reaction such as an inflammatory response that appears to worsen the symptoms. This is common amongst many PPID treatments as the horses sensitive immune response reacts'. If you need more info or are concerned about using any holistic approach alongside prescribed treatments, we'd recommend speaking to your vet.
Verified reviews from horse owners managing PPID alongside EQU StreamZ bands:
“I bought the Streamz bands for my horse, Erik, about 3 weeks ago for my 22 year old warmblood who suffers terribly with arthritis. He was also diagnosed with Cushings a year ago so I enquired as to why there was 'a warning' on the Streamz site regarding Cushings and potential adverses effects. After speaking to them I decided to give them a go and am pleased to report that I haven’t had any adverse effects whatsoever. Overnight the puffiness around his hocks significantly reduced... his previous check ligament injuries which are always puffy have also gone down! He was still tentative when light hacking but I’m thinking initially it was psychological as now he is striding out with full confidence again!! I’m so impressed, and more so happy for him. The ground is so hard and in the past he would be crippled now it's summer! I cannot stress enough what these EQU fetlock bands have done for him, they have given him his life back!” - Seanne Radmore
“Belle has Cushing's and arthritis in her hocks and fetlocks, she's struggled through the bad winter being in so much, she on bute and other painkillers to help her but last month she got to a point where she laid down all the time and when she got up she could barely move. 3 days after EQU Streamz she was getting up from lying down much better and moving around far better. She's mentally is a lot more on the ball, is having to be tied up again or she runs off and is being naughty to catch again! She isn't depressed in her stable, she's actually excited to see me and excited for her feed.I am SO relieved I bought these Streamz bands!" - Jazmine Rose.
“This is our pony called Sox. He is 24 years old, was diagnosed with cushings and also suffers from laminitis symptoms. He's been wearing his bands for 2 weeks now and for the first time in his entire life we now have to shout at him to slow him down!!! 5* for him and for me with my YOU StreamZ band too!” - Ellie Brooker
“What an amazing product!! I bought these for my 20year old arthritic horse who was just diagnosed with cushings so unable to have injections as his vet would have liked. I was very sceptical about buying these magnets as I was unsure on whether they would make a difference or not. There are so many other products on the market claiming to do similar things. After reading all the reviews of StreamZ I took the plunge and it was the best thing I have done!!! My horse is like a 4 year old again. He comes out of the stable with no stiffness, has a better range of movement and is generally a lot happier in himself. They are easy to clean and keep on. I wish I had found this product earlier!” - Ellise Brown
“I bought these for my 23 year old pony who was diagnosed with Cushings by our vet. He had become very slow and stiff on his back end. He has had the bands on for about 8 hours a day for 5 days now and the difference is remarkable! He is now keeping up with my 2 year old and seems a lot brighter and happier in himself!!” - Holly Stevens
“I have a 25 year old part bred Arab who has arthritis in several of his joints and also has Cushing's. I noticed his back legs were becoming quite swollen in the mornings from being in his stable and as soon as I started putting the EQU StreamZ bands on every night the swelling disappeared. I can't believe the difference they have made to him and he's definitely got a spring back in his step. I was cautious using the bands due to him having Cushing's but he has had no side effects at all and I'm so glad I decided to try them.” - Becky
“These have made a huge difference to both my 23yr old Irish sports horse and my 12 yr old mini Shetland. Both have Cushings and various arthritic problems but are much more comfortable and not requiring anti-inflammatory medications anymore.” - Annette Glendinning
Conclusion
Equine Cushing’s Disease, or Pituitary Pars Intermedia Dysfunction (PPID), is a common and complex condition that primarily affects older horses. While there is no cure for PPID, early diagnosis and proper management can significantly improve the quality of life for affected horses.
Recognising the signs of Cushing’s is crucial for timely intervention and ensuring a happy and healthy horse.
Treatment typically involves the use of Pergolide (Prascend), dietary management, exercise, and regular veterinary care. Additionally, complementary therapies like advanced bio-resonance therapy from EQU StreamZ Horse Bands have shown to provide further support by promoting natural healing processes and reducing inflammation.
By taking a proactive and comprehensive approach to managing Equine Cushing’s Disease, horse owners can help their animals lead healthier, more comfortable lives well into their senior years.
Sources
*R. C. Tatum, C. M. McGowan, and J. L. Ireland, Efficacy of pergolide for the management of equine pituitary pars intermedia dysfunction: A systematic review, The Veterinary Journal, vol. 266, p. 105562, Dec. 2020, doi: 10.1016/j.tvjl.2020.105562.
*N. Hague, A. E. Durham, and N. J. Menzies‐Gow, “Pergolide dosing compliance and factors affecting the laboratory control of equine pituitary pars intermedia dysfunction,” Vet. rec., Mar. 2021, doi: 10.1002/vetr.142.
* PPID primarily affects horses over the age of 10 (source, Royal Veterinary College)
* PPID occurs in up to 21.2% of horses aged 15 years older (source, The Veterinary Journal)
* 63% of horses with PPID are treated medically (source, National Library of Medicine)
* Of horses with PPID, 43% report a prevalence of Laminitis (source, Equine Veterinary Journal
