Post by muskyhusky on Oct 16, 2008 19:47:31 GMT -6
Cushing's disease causes increased drinking, increased urination, increased appetite, panting, high blood pressure, hair loss - usually evenly distributed on both sides of the body, pendulous abdomen, thinning of the skin, calcified lumps in the skin, susceptibility to skin infections and diabetes, weakening of the heartand skeletal muscles, nervous system disease and other symptoms. Most owners reach a point where the water consumption and urination become bothersome to them.
What to Watch For
Abnormal high blood concentration of cortisone results in the clinical symptoms of Cushing's syndrome.
These include:
Increased water consumption (polydipsia)
Increased Urination(polyuria)
Increased appetite (polyphagia)
Abdominal distension (pot-bellied appearance)
Loss of hair on the trunk
Chronic skin or urinary tract infections, excessive panting, lethargy, muscle weakness, and calcium deposits in the skin (calcinosis cutis) are other symptoms of Cushing's syndrome.
---------------------------------------------------------------------------------
Diagnosis
No single laboratory test definitively identifies Cushing's syndrome, and the disorder should not be diagnosed solely on the basis of laboratory tests. Your veterinarian should also consider the medical history and physical examination findings when establishing a diagnosis and determining the appropriate laboratory tests to perform. Several of the following diagnostic tests may be required for the diagnosis of Cushing's syndrome:
Complete blood count (CBC)
Biochemical profile
Urinalysis and bacterial culture of the urine
Blood Pressure
Radiographs (X-rays) of the chest and abdomen
Urine cortisol-to-creatinine ratio
Abdominal ultrasound examination
ACTH stimulation test
Low dose dexamethasone suppression test
Measurement of blood ACTH concentration
High dose dexamethasone suppression test
CT (computed tomography) or MRI (magnetic resonance imaging) scans of the brain or abdomen.
---------------------------------------------------------------------------------
Treatment
Several approaches may be used to treat dogs with Cushing's syndrome. Treatment options depend primarily on whether the Cushing's syndrome is pituitary-dependent or adrenal-dependent.
Pituitary-dependent Hyperadrenocorticism
Medical therapy with o,p'-DDD (mitotane or Lysodren®) causes selective destruction of the cortisone-producing portions of the adrenal gland and limits the ability of the gland to produce cortisone.
Ketoconazole (Nizoral®) is an anti-fungal drug that also blocks the synthesis of cortisone in the adrenal gland. It is sometimes used to treat hyperadrenocorticism.
L-Deprenyl increases dopamine concentration in the brain. Increased dopamine concentration may decrease cortisone production in the adrenal glands. The use of L-deprenyl to treat Cushing's syndrome in the dog is very controversial. Some veterinarians believe it has a beneficial clinical effect whereas others have found no evidence of an effect despite extensive laboratory testing of treated dogs.
Adrenal-dependent Hyperadrenocorticism
Surgical removal of an adrenal tumor is a difficult, but potentially curative surgery. Surgery is not indicated if the adrenal tumor has invaded adjacent vessels and organs or spread distantly (metastasized).
Adrenal tumors also can be treated medically with mitotane or ketoconazole. Medical therapy may be the only choice if the tumor has invaded locally or spread distantly.
Home Care
Follow your veterinarian's instructions very closely when administrating medications, especially in the induction phase when using mitotane. Observe your dog for weakness, vomiting, diarrhea, loss of appetite or change in attitude. You should also observe your dog for improvement or worsening of clinical signs.
Follow-up with your veterinarian for routine re-evaluation of blood tests so as to maximize the chance for successful treatment.
Preventative Care
There is no known way to prevent Cushing's syndrome. However, some preventative measures may lead to earlier diagnosis and potentially more effective treatment:
As your dog gets older, more frequent routine visits to the veterinarian may identify early symptoms of the disease.
Routine performance of blood tests (complete blood count, biochemical profile, urinalysis) in older dogs may identify laboratory abnormalities associated with hyperadrenocorticism.
Monitor your dog for any changes in behavior or attitude, especially increased water consumption, increased urinations, and increased appetite
----------------------------------------------------------------------------
Did you know that they actually charge to take a dogs blood pressure, I mean I couldn't believe it when she told me that..
What should your dogs BP be?
A systolic ABP should not exceed 170 to 180 mm Hg and diastolic should not exceed the 100 to 110 mm Hg range.
Cushing's disease is probably more accurately referred to as hyperadrenocorticism -- the production of too much adrenal hormone, in particular corticosteroids. It can be naturally occurring or due to over administration of corticosteroids such as prednisone (iatrogenic Cushing's). The latter is easy to cure - just cut out the corticosteroid administration slowly to allow the body to return to normal function. The former is more difficult.
Hyperadrenocorticism occurs for two reasons --- a tumor of the adrenal gland that produces adrenal hormones or stimulation of the normal adrenal glands from the hormones that control it. The primary reason for this to occur is a pituitary gland tumor that produces excessive ACTH, which stimulates the adrenal gland to produce corticosteroids. Adrenal gland tumors account for 15% of the cases of spontaneous hyperadrenocorticism. Pituitary tumors account for 85%.
Cushing's disease causes increased drinking, increased urination, increased appetite, panting, high blood pressure, hair loss - usually evenly distributed on both sides of the body, pendulous
abdomen, thinning of the skin, calcified lumps in the skin, susceptibility to skin infections and diabetes, weakening of the heart and skeletal muscles, nervous system disease and other symptoms. Most owners reach a point where the water consumption and urination become bothersome to them.
The diagnosis of Cushing's can be done with several blood tests. A general hint of Cushing's can be obtained by a blood panel. To confirm it, a test known as a low dose dexamethasone test is done. A baseline blood sample is drawn in the morning, an injection of dexamethasone given and a follow-up blood test done 8 hours later. In a normal dog, the dexamethasone should suppress cortisol levels in the blood stream. In Cushing's disease this effect does not occur. Once the disease is diagnosed, it is possible to differentiate between the adrenal tumors and pituitary gland tumors using a second test, a high dose dexamethasone suppression test. Most dogs with pituitary tumors will have cortisol suppression on this test. There are other tests used, including ACTH response tests and urine cortisol/creatinine ratios to diagnose this disease. X-rays and ultrasonography can help determine if an adrenal gland tumor is present.
If it can be determined that there is an adrenal gland tumor, it can be removed. Many veterinarians prefer to have a specialist attempt this since the surgical risks can be high. Pituitary gland tumors are not usually removed in veterinary medicine. This situation is treated using Lysodren (o'p'-DDD, which is a relative of DDT) or ketaconazole. Some research with Deprenyl for treatment of this is being done, too, I think. Lysodren selectively kills the outer layer of the adrenal gland that produces corticosteroids. By administering it in proper amounts it is possible to kill just enough of the gland off to keep the production of corticosteroids to normal levels. Obviously, close regulation of this using blood testing is necessary since overdoing it can cause severe problems with Addison's disease - hypoadrenocorticism. Adverse reactions to Lysodren occur at times but it is the standard treatment at this time. Over medication with Lysodren can cause inappetence, vomiting, diarrhea, lethargy and weakness. If any of these signs occur then your veterinarian should be immediately notified.
Treatment of Cushing's disease caused by pituitary tumors is symptomatic therapy -- it does not cure the pituitary tumor.
The average lifespan of dogs diagnosed with Cushing's, with or without treatment is estimated at 2 years by Dr. Mark Peterson, but in a recent conversation with another endocrinologist I came away with the impression that this was an "educated guess" rather than the result of extensive survey of Cushing's patients. At present, though, I think that treatment should be viewed as a means of providing a better quality lifestyle rather than as a method of extending longevity.
