Common names or abbreviations:Addison's Disease (AD), common name
Hypoadrenocorticism, commonly used scientific name
Adrenal insufficiency
Adrenocortical Hypofunction are less commonly used terms.
Description or definition:The adrenal gland, one on each kidney, is made up of two layers, the cortex and the medulla. The outer area, or cortex, secretes corticosteroid hormones such as cortisol and aldosterone. The medulla, part of the sympathetic nervous system, secretes epinephrine (adrenaline), which is generally not affected by AD. Addison's disease is the insufficient production and secretion of hormones (glucocorticoids, mineralocorticoids and androgens) by the adrenal gland cortex. In this disorder, the adrenal gland fails to produce enough of a steroid hormone called aldosterone. This hormone is very important in maintaining a normal balance of minerals in the blood. This is a disease that if left untreated, leads to death.
It is believed that many of the features of canine AD resemble those in humans, which is immune-mediated destruction of the adrenal cortices. (Autoimmunity is a misdirected immune response, in which the body's defenses become self-destructive. Autoimmunity may result from a combination of factors such as: genetic predisposition, hormonal factors and environmental triggers such as viral infections and vaccinations.)
It was originally thought that AD typically affected young to middle-aged female dogs, the average age being about 4 years old. Researchers have found, however, that AD equally affects males and females. Notably, the Bearded Collie, the West Highland White Terrier, the Standard Poodle, the Portuguese Water Dog, Great Dane, Rottweiler and the Leonberger are considered to have unacceptable rates of Addison's disease.
Symptoms:
The symptoms of Addison's disease can be vague. More importantly, they are similar to the symptoms of many different problems. A hallmark symptom of Addison's disease is impaired tolerance to stress. Even mild physical or emotional stress can cause an Addisonian Crisis (please see link to wheatenguy for list of stressors).
Commonly reported symptoms. Severity can vary dramatically from dog to dog.
Anorexia
Thin/Weight Loss
Depression/Lethargy
Vomiting/Diarrhea
Weakness
Collapse
Shaking and Shivering
Excessive urination with or without excessive thirst
Waxing and Waning Course of Illness
Painful/Sensitive Abdomen
Fatigue/exercise intolerance
The dog may also appear clumsy and unable to climb stairs or jump on the bed. This may be due to muscle loss or weakness. The dog does not have the strength to do normal activities.
Diagnosis:
Studies have found that between 33 to 51% of dogs with Addison's were diagnosed during a crisis as this maybe the first time the owner suspects anything is wrong and may be fatal if not treated promptly. Addisonian crisis occurs when the dog is in circulatory collapse and shock.
On examination by the veterinarian the dogs were noted to have;
Mental Depression
Thin/emaciated
Muscular Weakness
Dehydration
Slow weak pulse
Blood in feces
Gastrointestinal hemorrhage
Collapse
Abdominal pain
Pale mucous membranes/anemia
Low temperature
Low blood pressure
Grand Mal Seizure
After a crisis, diagnostic testing is critical to support diagnoses of Addison's disease. The absence of a stress leukogram in a sick dog may be a clue to consider Addison's disease. A more specific test, an ACTH challenge, should be performed to confirm the disease.
Treatment:
There are two stages of treatment for Addison's disease; in-hospital treatment (virtually every dog treated with IV therapy, glucocorticoids, and mineralocorticoids have shown rapid improvement and there may be a need for intensive monitoring and therapy for several days to stabilize the dog.) and long-term treatment. Long-term treatment involves the administration of hormones in one of two forms; either a daily pill or a shot that is given about every 25 days. Stress should be minimized whenever possible.
Prevention:
According to studies done at several Veterinary Universities, the late-onset failure of adrenal gland function is clearly inherited and appears to be regulated by a single gene that is inherited as an autosomal recessive. It is thought that immune system-mediated destruction of the adrenal gland is the most common cause of primary adrenal gland failure. Other causes can include infection or inflammation in the adrenal gland; abnormalities in blood supply to the adrenal gland or bleeding within the gland; infiltration of cancer cells within the adrenal gland; the deposition of abnormal proteins within the adrenal gland; and physical trauma to the glands. Rapid withdrawal of drugs such as prednisone after chronic administration and overdoses of drugs used to treat Cushing's disease can result in adrenal gland failure. Secondary adrenal gland failure can occur due to primary problems in either the hypothalamus or the pituitary gland.
Links to sites about this disease:http://wheatenguy.tripod.com/addisons.html
http://www.supervet.co.uk/dog/addisons.html
http://www.cah.com/library/addison.html
http://www.vetmed.wsu.edu/clientEd/addisons.asp
http://www.animalrightshospital.com/encyclopedia/addisons.disease.html
http://www.akcchf.org/research/grants/disease/a.htm
http://www.healthypet.com/FAQ/pet_diseases-12.html
http://www.glenellynrx.com/encycEntry.cfm?ENTRY=71&COLLECTION=EncycIllness
http://www.vizsladogs.com/ARTICLES/addison.htm
http://www.addisondogs.com/ (Support Group)
http://www.vetstop.com.au/Info/infaddison.htm
http://www.k9addisons.com/ad.html
http://www.medhelp.org/www/nadf3.htm
http://www.fda.gov/cvm/efoi/section2/140583111488.html (Info on ACTH)
http://www.southpaws.com/news/99-1-addisons-disease.htm
Hypoadrenocorticism, commonly used scientific name
Adrenal insufficiency
Adrenocortical Hypofunction are less commonly used terms.
Description or definition:The adrenal gland, one on each kidney, is made up of two layers, the cortex and the medulla. The outer area, or cortex, secretes corticosteroid hormones such as cortisol and aldosterone. The medulla, part of the sympathetic nervous system, secretes epinephrine (adrenaline), which is generally not affected by AD. Addison's disease is the insufficient production and secretion of hormones (glucocorticoids, mineralocorticoids and androgens) by the adrenal gland cortex. In this disorder, the adrenal gland fails to produce enough of a steroid hormone called aldosterone. This hormone is very important in maintaining a normal balance of minerals in the blood. This is a disease that if left untreated, leads to death.
It is believed that many of the features of canine AD resemble those in humans, which is immune-mediated destruction of the adrenal cortices. (Autoimmunity is a misdirected immune response, in which the body's defenses become self-destructive. Autoimmunity may result from a combination of factors such as: genetic predisposition, hormonal factors and environmental triggers such as viral infections and vaccinations.)
It was originally thought that AD typically affected young to middle-aged female dogs, the average age being about 4 years old. Researchers have found, however, that AD equally affects males and females. Notably, the Bearded Collie, the West Highland White Terrier, the Standard Poodle, the Portuguese Water Dog, Great Dane, Rottweiler and the Leonberger are considered to have unacceptable rates of Addison's disease.
Symptoms:
The symptoms of Addison's disease can be vague. More importantly, they are similar to the symptoms of many different problems. A hallmark symptom of Addison's disease is impaired tolerance to stress. Even mild physical or emotional stress can cause an Addisonian Crisis (please see link to wheatenguy for list of stressors).
Commonly reported symptoms. Severity can vary dramatically from dog to dog.
Anorexia
Thin/Weight Loss
Depression/Lethargy
Vomiting/Diarrhea
Weakness
Collapse
Shaking and Shivering
Excessive urination with or without excessive thirst
Waxing and Waning Course of Illness
Painful/Sensitive Abdomen
Fatigue/exercise intolerance
The dog may also appear clumsy and unable to climb stairs or jump on the bed. This may be due to muscle loss or weakness. The dog does not have the strength to do normal activities.
Diagnosis:
Studies have found that between 33 to 51% of dogs with Addison's were diagnosed during a crisis as this maybe the first time the owner suspects anything is wrong and may be fatal if not treated promptly. Addisonian crisis occurs when the dog is in circulatory collapse and shock.
On examination by the veterinarian the dogs were noted to have;
Mental Depression
Thin/emaciated
Muscular Weakness
Dehydration
Slow weak pulse
Blood in feces
Gastrointestinal hemorrhage
Collapse
Abdominal pain
Pale mucous membranes/anemia
Low temperature
Low blood pressure
Grand Mal Seizure
After a crisis, diagnostic testing is critical to support diagnoses of Addison's disease. The absence of a stress leukogram in a sick dog may be a clue to consider Addison's disease. A more specific test, an ACTH challenge, should be performed to confirm the disease.
Treatment:
There are two stages of treatment for Addison's disease; in-hospital treatment (virtually every dog treated with IV therapy, glucocorticoids, and mineralocorticoids have shown rapid improvement and there may be a need for intensive monitoring and therapy for several days to stabilize the dog.) and long-term treatment. Long-term treatment involves the administration of hormones in one of two forms; either a daily pill or a shot that is given about every 25 days. Stress should be minimized whenever possible.
Prevention:
According to studies done at several Veterinary Universities, the late-onset failure of adrenal gland function is clearly inherited and appears to be regulated by a single gene that is inherited as an autosomal recessive. It is thought that immune system-mediated destruction of the adrenal gland is the most common cause of primary adrenal gland failure. Other causes can include infection or inflammation in the adrenal gland; abnormalities in blood supply to the adrenal gland or bleeding within the gland; infiltration of cancer cells within the adrenal gland; the deposition of abnormal proteins within the adrenal gland; and physical trauma to the glands. Rapid withdrawal of drugs such as prednisone after chronic administration and overdoses of drugs used to treat Cushing's disease can result in adrenal gland failure. Secondary adrenal gland failure can occur due to primary problems in either the hypothalamus or the pituitary gland.
Links to sites about this disease:http://wheatenguy.tripod.com/addisons.html
http://www.supervet.co.uk/dog/addisons.html
http://www.cah.com/library/addison.html
http://www.vetmed.wsu.edu/clientEd/addisons.asp
http://www.animalrightshospital.com/encyclopedia/addisons.disease.html
http://www.akcchf.org/research/grants/disease/a.htm
http://www.healthypet.com/FAQ/pet_diseases-12.html
http://www.glenellynrx.com/encycEntry.cfm?ENTRY=71&COLLECTION=EncycIllness
http://www.vizsladogs.com/ARTICLES/addison.htm
http://www.addisondogs.com/ (Support Group)
http://www.vetstop.com.au/Info/infaddison.htm
http://www.k9addisons.com/ad.html
http://www.medhelp.org/www/nadf3.htm
http://www.fda.gov/cvm/efoi/section2/140583111488.html (Info on ACTH)
http://www.southpaws.com/news/99-1-addisons-disease.htm