Not too long ago, I did an article about Cushing's disease and its relationship to cats and after much research decided, that dog owners needed to be alerted to this disease, also.
What is Cushing's disease? Cushing's disease is a disorder of the adrenal glands, a pair of inch long kidney bean shaped glands situated just above the kidneys.
Their function is to manufacture and secrete potent hormones directly into the blood stream to facilitate and regulate a whole bunch of bodily processes.
There are about 30 or more hormones secreted by the adrenal glands, among them is a very important one called cortisol.
Cortisol is a hormone that is involved in the metabolism of carbohydrates, fats and proteins, the maintenance of normal blood sugar levels, muscle development and other functions related to tissue growth and repair.
Cortisol is also an important part of a dog's "fight or flight" response.
In any stressful situation a dog may face, these glands push more cortisol into the blood stream, which in turn releases stored energy, which can be used to face, whatever situation the dog is under.
Whether it is a threat of an oncoming confrontation, an infection or a physical challenge such as surgery or other illnesses.
Under normal conditions, the amount of cortisol that is sent into the blood stream is controlled by another tiny oval gland called the pituitary gland, which is located at the base of a dog's brain.
The pituitary gland's job is to send a message to the adrenal glands via a hormone called "adrenocorticotropic" (ACTH) when it needs cortisol, when it has enough it stops sending ACTH.
Cushing's disease happens when the excessive secretion of cortisol is not stopped, which can be fatal to the dog.
There are two reasons why this happens and both reasons boil down to cancer.
The most common one is a tiny slow growing benign cancer located in the pituitary gland.
This cancer is so small that is barely takes up any room and it does not press on anything, however it causes an excessive amount ACTH to be sent to the adrenal glands, which in turn causes the glands to grow bigger and produce more cortisol.
This condition known as "pituitary-dependent Cushing's disease is the cause of about ninety percent of the Cushing's disease cases.
Interestingly enough, most of these cases are small breed dogs.
The cure for this type of cancer is the use of drugs, as trying to remove the growth is not possible because the pituitary gland is inaccessible.
So the treatment is directed to the adrenal glands.
Radiation will not work and so drugs are used, this is a form of chemotherapy, once you start, the treatment goes on forever in order to control the disease.
Depending on the dog's response, treatment will require weekly treatments and monthly checks by the vet to see what the cortisol levels are.
Most dogs will respond to this treatment and have an extended life.
The other ten percent of these cases are due to cancer in the adrenal glands.
Fifty percent of the time the tumor is benign and the other fifty- percent of the time the tumor is malignant.
The tumor grows and causes the gland to produce more cortisol The benign cases can be treated, the malignant ones do not respond to radiation or chemotherapy, as the amount of drugs necessary would cause unacceptable side effects.
If the malignant cancer has not spread to other parts of the body, it is possible to remove it surgically.
Unfortunately, by the time this type of Cushing's disease is diagnosed, it is too late to perform surgery, What are the signs of Cushing's disease you should be aware of? If your dog suddenly starts to drink a great deal of water and is urinating frequently, these are classic signs to be aware of.
Granted they may be signs of other problems, too, but I would take my dog to the vet, as soon as I noticed these two particular signs.
A dog with Cushing's disease will also develop a large appetite due to the effect the cortisol has on the insulin in the body.
Periods of panting and nervousness, which may include constant pacing, may also be noticed.
The dog's muscles will become weak and the dog maybe prone to falling, which can cause injuries to the knees, hips and other joints.
A sign of advanced Cushing's disease is a potbelly.
What is happening, is the cortisol is telling the body to break down fat and to deliver it to the liver for processing.
The liver can only process so much and the access is stored and the end result is a "pot belly.
" Another sign of advanced Cushing's disease is the loss of hair.
The hair loss is not random; it will appear on both sides of the body or on the insides of the thighs.
It will not itch, as the hair loss is the cause of too much cortisol, however, if it does itch for some reason, your dog may also have a skin infection.
Cushing's disease is usually found in dogs that are middle-aged or older.
Small dogs such as Cocker Spaniels and poodles are usually between the ages of eight and ten, while larger dogs show signs around the ages of five to six years of age.
Cortisol plays such a significant role in so many bodily functions, with a vast range of serious complications, which may take months to years to develop.
It can cause many serious problems such as cardiovascular problems, muscle strength, interfere with blood clotting, and affect the body's ability to ward off infection.
This is again another situation, where it is important for the owner of a dog, to have a close relationship with its animal.
By knowing your dog's normal behavior patterns and paying close attention to its actions, you will be able to notice any differences in behavior or eating patterns and get your pet to the vet as quickly as possible.
My favorite saying is "an ounce of prevention is worth a quick trip to the vet, as you may just be saving yourself a big vet bill later on.
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