cushing's disease (hyperadrenocorticism) - Denes Natural Pet Care

CUSHING’S DISEASE (HYPERADRENOCORTICISM)
FACT SHEET 51
INTRODUCTION
Cushing’s disease or Hyperadrenocorticism, is a relatively common endocrine
based condition in which the body produces excessive amounts of the steroid
hormone cortisol. It is named after Dr Harvey Cushing, a famous neurosurgeon
who was the first doctor to recognise the condition in people. Cushing’s disease is
also seen in dogs, often affecting particular breeds such as Miniature & Toy
Poodles, Dachshunds and some of the smaller terrier breeds. The condition can
be artificially induced accidentally by steroidal based drugs prescribed to treat
skin problems.
THE ROLE OF CORTISOL
In healthy animals, cortisol is naturally produced by the two adrenal glands, one
of which is located close to the each of the kidneys. This steroid hormone is vital
for good health and is involved in some important functions within the body:
• Modulating the immune system
• Maintenance of blood pressure
• Regulating the action of insulin in controlling blood sugar levels
• Regulating how the body uses protein, fats and carbohydrates
The amount of cortisol excreted by the adrenal glands is very closely regulated
and finely balanced by a hormone produced by the pituitary gland which is
located at the base of the brain. Cortisol is mainly produced at times of stress to
help the body cope with difficult situations. In Cushing’s disease however, the
levels of cortisol in the blood remain high causing a number of symptoms to
appear.
WHAT CAUSES CUSHING’S DISEASE
There are two types of Cushing’s disease.
Most cases of Cushing’s disease occur in animals aged 7 or older. Nearly all cases
are caused by a tumour in the pituitary gland. This type is termed Pituitary
dependant Cushing’s disease and often occurs in certain breeds of dog. The
tumour, which is very small and benign, usually causes no symptoms within the
brain itself. However, it does cause excessive amounts of a hormone called
adrenocorticotropic hormone (ACTH) to be produced which stimulates the adrenal
glands to enlarge and excrete large quantities of cortisol.
The other form of Cushing’s disease is called Adrenal dependant Cushing’s
disease. This type is caused by a tumour developing in one of the adrenal glands
resulting in excessive amounts of cortisol being secreted. There is no breed
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predilection for this type of Cushing’s disease, although large dog breeds do seem
to be more commonly affected.
Artificially induced, reversible Cushing’s disease, can be caused by veterinary
administration of steroidal based drugs to treat some common conditions such as
allergies, eczema or arthritis. Fortunately the signs of Cushing’s disease usually
disappear quite quickly once the drugs are stopped.
SIGNS & SYMPTOMS
In the early stages, the condition can be very hard to detect, particularly as the
symptoms and changes linked with the illness appear very slowly, often over
many months or even years. To complicate matters, the symptoms can mirror
some of the changes associated with old age, which only adds to the difficulty in
detecting the problem. The most common symptoms associated with increased
levels of cortisol in the blood are:
• Increased thirst (polydipsia)
• Increased urination (polyuria)
• An increase in appetite and weight gain
• Loss or thinning of the hair over the flanks without any irritation
• Thinning of the skin
• Cessation of hair growth
• Changes in hair colour and texture
• Enlargement of the abdomen caused by fat deposits in the liver
Less common signs include:
• Calcium deposits in the skin (Calcinosis cutis)
• Excessive bruising
• Comedones (blackheads)
• Poor or delayed healing
• Stretch marks with a purple hue on the abdomen
• Cessation of seasons in bitches
• Testicular atrophy in dogs
• Muscle wasting and subsequent weakness
• Difficulty moving
• Suppression of the immune system
• Repeated infections
• Lethargy
• Exercise intolerance
Other than the presenting symptoms, your vet may decide to undertake further
investigations or tests to confirm the diagnosis. Common blood findings include:
• Raised cholesterol levels
• Increased levels of liver enzymes
• Increased levels of bile acids
There are also specific tests which your vet may perform to assess adrenal
function and to further confirm the diagnosis.
• ACTH stimulation test
• Low dose dexamethasone suppression test
• ACTH assay to determine the level of ACTH in the blood
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Further investigations using ultrasound, X-rays and CT/MRI scans can be of
additional help in establishing a diagnosis.
TREATMENT
Conventional options
There are a variety of drugs available to treat Cushing’s disease:
Mitotane (Lysodren). This drug works by destroying the parts of the adrenal
gland that produce cortisol so less hormone is produced. This medicine also has
the advantage that it kills the cells in adrenal tumours. As most cases of
Cushing’s disease are caused by a microscopic tumour in the pituitary gland,
mitotane does not address the cause of the disease directly, but rather by
reducing the amount of cortisol produced as a result of the pituitary tumour. The
use and dose of this drug needs careful monitoring by your vet with frequent
blood tests to check on your pet’s progress.
Selegilene (Anipryl). This drug works directly on the pituitary gland by reducing
the production of ACTH. It has no effect on the adrenal glands directly. It does
not work in dogs that have adrenal tumours and works best in dogs with mild to
moderate symptoms of the illness.
Trilostane (Vetoryl). This is a much newer drug which inhibits cortisol production
by the adrenal glands. It can be used to treat both forms of the illness. Unlike the
other drugs it neither destroys adrenal tissue nor decreases ACTH production.
Routine blood tests are needed to monitor your pet’s progress to ensure that the
disease is under control.
In rare instances, a surgical approach may be needed to remove an adrenal
tumour. This would normally be carried out in a specialist centre as the surgery is
technically quite difficult to perform. In addition careful monitoring is required
post-operatively to ensure a full recovery.
Most animals with Cushing’s disease are elderly and may have other health issues
as well. However, if the condition is monitored and managed adequately, many
animals will go on to lead a normal life.
How Denes can help
Although we do not have any specific treatments for Cushing’s disease, we are
able to offer supportive treatment to enhance the quality of life for those dogs
with the illness.
Denes Aloe vera
Aloe vera is useful as it supports the immune system. The majority of animals
with Cushing’s disease will have a weakened immune system and are, therefore,
at greater risk of infection. Denes Aloe vera is very palatable and easily added to
food and has additional health benefits such as supporting the health of the bowel
and cleansing the body of toxins.
Denes Milk Thistle+ Powder
Blood testing of dogs with Cushing’s disease often reveals raised levels of liver
enzymes and bile acids. Both Milk thistle and Dandelion root are herbs which can
support liver function and protect the liver from damage. Denes Milk Thistle+
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Powder which includes Dandelion root is an ideal supplement to give to all dogs
with Cushing’s especially those on conventional medication.
Denes Homeopathic Phosphorus 30c drops
Phosphorus in its homeopathic form will support the liver and may help ease
some of the symptoms of Cushing’s, particularly the thirst and urination
problems.
Denes Homeopathic Nux vomica 30c drops
Nux vomica will also support the liver and will help generally by clearing the body
of toxins.
Denes Arnica 30c drops
We would recommend Arnica for those animals where bruising is a repeated
problem due to the Cushing’s causing fragility of the blood vessels in the skin.
Denes All in One+ Powder
This is an ideal general supplement to give in all cases. It is based on Seaweed,
Wheatgrass, Barleygrass, Alfalfa and Spinach and provides a rich source of
natural vitamins, minerals and trace elements. In addition, All in One+ Powder
will help improve the health of the skin and the coat, which is often poor in
Cushing’s cases.
Denes Greenleaf Tablets and Denes Garlic Tablets
Both these licensed herbal remedies will support general health by helping the
body to remove toxins and by supporting the immune system respectively. This
combination is particularly effective where there is a problem with repeated skin
infections.
Other Denes Fact Sheets to read
• Aloe vera
• Homeopathic remedies
• All in One+ Powder
• Garlic
• Nettles (the main active ingredient in Greenleaf Tablets)
If you have any queries concerning your pet’s health or feeding problems, you
can contact us for free pet care advice by:
• Visiting our website www.denes.com
• Emailing us at info@denes.com
• Calling us on 01273 325364 Mon-Fri, 9am – 12Noon
• Writing to us at:
Denes Natural Pet Care Ltd,
2 Osmond Road,
Hove, East Sussex BN3 1TE.
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