What if Cushings is left untreated

Cushing's Syndrome in Dogs

The Cushing Syndrome goes back to the neurosurgeon Dr. Harvey Cushing, who in 1932 first established a connection between certain symptoms and an adrenal tumor in humans. Since then, the term has been used for a variety of causes that lead to the development of a specific symptom complex. The term Cushing as well as hyperadrenocorticism stand for an overproduction of cortisone.

The basics

The adrenal glands are two small hormone-producing glands that are located next to the kidneys. They are stimulated by a hormone-producing gland in the brain, the pituitary gland, to release their hormones. While the adrenal glands can also influence the release of hormones by the pituitary gland. This interaction is known as the pituitary-adrenal axis.


Pituitary Cushing

This type is found in 80-85% of all dogs with naturally occurring cushing. The cortisone-stimulating hormone (medical ACTH) is increasingly released. In over 90% of these dogs, a tumor in the pituitary gland is the cause.

Adrenal tumors

15-20% of affected dogs have an adrenal tumor that releases large amounts of cortisone. Typically, the tumor is only found in one of the two adrenal glands. Tumors are less common in both adrenal glands. In addition to cortisone-producing tumors, other tumors also occur in the adrenal glands with different frequencies; these must be ruled out clinically or pathologically.

rare cases

In rare cases, tumors can be found in both the pituitary gland and the adrenal gland.

Other tumors can also trigger Cushing's syndrome, and an overproduction of another hormone (for example sex hormones) can rarely trigger the syndrome.

Symptoms of Cushing's Syndrome

The signs usually develop slowly over a certain period of time. Many dog ​​owners consider them to be part of the normal aging process. It is therefore not surprising that many dogs have been showing symptoms for months before a definitive diagnosis is made. Affected dogs usually have a good nutritional status and a good appetite. The preliminary report, which you, as the animal owner, provide to the veterinarian, contains the most important information for making a diagnosis. Important questions in this context are:

  • Has your dog been given any medication lately?
  • Does your dog drink and urinate normally?
  • Does your dog have an increased appetite?
  • Can your dog jump in the car or on the couch?
  • Does your dog occasionally pant in peace?
  • Does your dog sleep more?

Dogs with Cushing's syndrome may have only one symptom or multiple symptoms. The classic symptoms are:

  • Increased thirst and urination
  • Hair loss
  • Drooping, pear-shaped belly
  • Enlargement of the liver
  • Increased appetite
  • Muscle weakness
  • Missing heat
  • muscular dystrophy
  • Blackheads
  • Panting
  • Dark discoloration of the skin
  • Decrease in testicle size
  • Facial nerve paralysis (so-called facial nerve palsy)

Many dogs with Cushing also have a urinary tract infection. However, some do not show any specific symptoms. These are suppressed by the anti-inflammatory influence of the cortisone. A small proportion of the dogs also develop diabetes mellitus and, as a result, show weight loss.

Cushing's Syndrome is a slowly progressing disease that can cause some dogs to develop acute weakness, pain, and pale mucous membranes. These are usually caused by acute bleeding in the abdomen and are an absolute emergency.

This is how the diagnosis can be made

It always starts with a clinical suspicion based on history and physical examination. Further investigation is needed to investigate this suspicion. An abdominal ultrasound should always be performed. In this context, a sterile urine sample can be obtained, which should be examined for bacteria. In addition, the urine should be checked for signs of inflammation. The ratio of cortisone to a specific kidney value can be measured in the urine. This ratio gives an indication of the likelihood of Cushing's syndrome.

X-rays also reveal specific changes that make cortisol overproduction likely. The use of an MRI or CT examination can be helpful under certain conditions.

In addition to a normal blood count, specific tests for Cushing's syndrome should be done. These tests complement each other; they are seldom so clear that a single test is sufficient. It may also be necessary to carry out a test repeatedly, as it is sometimes falsified by acute and chronic stress.


What happens with untreated cushing?

The increased cortisol level reduces the body's defenses. As a result, these dogs are prone to recurring skin and urinary tract infections. The typical symptoms of the disease also persist (for example, cravings, increased drinking and increased urination). The cortisone also changes the composition of the blood and thus leads to increased thrombosis. Thrombosis is the cause of death in slightly more than half of all Cushing patients. In addition, diabetes mellitus can develop as a secondary disease.

The most common reason why dog ​​owners choose not to treat Cushing's syndrome is because of the high cost. Not only are the drugs comparatively expensive (the heavier the dog, the more expensive), the necessary blood tests are also very expensive.

Atypical Cushing Syndrome

It is estimated that around 30% of all cases can be categorized as atypical Cushing's syndrome. In these cases the symptoms are fully developed. However, none of the tests used can confirm the diagnosis. Trial treatment is often the only way to make a diagnosis. These patients are likely to produce a different metabolic equivalent that will respond just as well to treatment.



In Germany, only one drug is currently approved for treatment. The active ingredient trilostane is approved for once-a-day administration. It reaches the highest concentration in the bloodstream after 1.5-2 hours. The active ingredient is almost completely eliminated after 10-18 hours. About 80% of the animals react well enough to the once-daily dose. For the other 20%, a twice-daily dose is preferred. Under certain circumstances, a twice-daily dose should be aimed for, e.g. with simultaneous diabetes mellitus. In general, the disease can be controlled more effectively if the drug is given twice a day. In addition, the effectiveness of the drug is increased if it is administered with the feed. Within 7-10 days there should be a certain increase in activity and a decrease in water intake or urine output.

In addition to trilostane, other drugs for treatment are described. However, none of these drugs is approved for this treatment in Germany and may therefore not be used or only used under very strict criteria.


Since in most cases it is a tumor, the possibility of tumor removal should be mentioned at this point. For adrenal tumors, surgery is the treatment of choice. Although it can come with some potential complications. After intensive consultation, the decision is made solely by the animal owner.

The operation on the head or the removal of the pituitary gland is an extremely difficult procedure that should only be performed by experienced neurosurgeons. High demands are attached to both the operation and the follow-up care that follows. Therefore, this operation is only carried out in a few specialized centers in Europe.


A gentler way is to irradiate pituitary tumors. This type of treatment has variable success and usually does not lead to a cure for the disease. In most cases it can produce an improvement. This treatment is not fully recommended for dogs with large pituitary tumors.

Complications and secondary diseases in Cushing's syndrome

Large pituitary tumors

In general, there is always a risk of growth in tumors. Neurological symptoms are caused by the increase in size in 15-20% of cases. Neurological signs are usually subtle at first. A slight change in behavior can be the first sign and later on it can slowly be replaced by listlessness, restlessness, and occasionally aggressive behavior, disorientation, loss of appetite and weight loss. In the late course, gait disorders, urge to wander and lack of responsiveness are possible. Some dogs are mistakenly diagnosed as blind because these types of tumors produce an inadequate reflex response to visual stimuli.

Adrenal tumors

Here, too, complications often arise due to an increase in size. Usually these tumors grow into blood vessels and can metastasize. The rupture of these blood vessels can lead to abdominal bleeding or thrombosis.

high blood pressure

If Cushing's syndrome is left untreated, high blood pressure is a common problem (approx. 85%). In dogs that have a well-controlled cushing, around 40% are affected. Certain secondary diseases, e.g. kidney dysfunction, are associated with high blood pressure. Permanently high blood pressure can damage other organs (e.g. kidneys, brain and circulatory system) and should therefore be treated consistently.

Pelvic inflammation

Urinary tract infections are a common finding in people with Cushing's syndrome. A urinary bladder infection can easily ascend into the kidneys. Patients may or may not show signs of a urinary tract infection. The typical symptoms can be suppressed by the anti-inflammatory effect of the cortisone.

Urinary stones

Some problems with Cushing patients arise from an imbalance in the calcium balance. Calcium oxalate urinary stones, skin calcifications (medical calcinosis cutis) and other soft tissue calcifications can occur (especially in the lungs and kidneys). Cortion increases the excretion of calcium. The risk of calcium oxalate stones in patients with Cushing's syndrome is 10 times higher than in other patients.