Addisons

Addison's disease

Also known as chronic adrenal insufficiency, is a rare endocrine disorder in which the adrenal glands do not produce enough steroid hormones (glucocorticoids and often mineralocorticoids) and may occur as the result of many underlying causes. The condition is generally diagnosed with blood tests, medical imaging and additional investigations.Treatment involves replacement of the hormones. If the disease is caused by an underlying problem, it may be possible to address that.

This disease has symptoms that are common to many other ailments, making diagnosis or results in mis-diagnosis. But once Addison’s is correctly diagnosed, a properly treated dog can live a normal, active life.

Addisons has been diagnosed in several dogs in the last few years and is sadly creeping up in its numbers, unfortunately there are currently no tests to see if breeding dogs carry this disease. This is why DNA testing dogs now is important, even if all our dogs are coming back clear, because in the future a test may exist for diseases like Addisons, and we may be able to test all dogs, even historical dogs, thanks to their DNA

There are three forms of Addison’s disease: primary, secondary and atypical. Primary and atypical Addison’s are usually the result of immune mediated damage to the glands. Secondary hypoadrenocorticism is from failure of the pituitary to stimulate the adrenals with adrenocorticotropic hormone (ACTH). It is important for you to know which type of Addison’s disease your dog is being treated for.

CAUSES

Adrenal dysgenesis

All causes in this category are genetic, and generally very rare. These include mutations to the SF1 transcription factor, congenital adrenal hypoplasia (AHC) due to DAX-1 gene mutations and mutations to the ACTH receptor gene (or related genes, such as in the Triple A or Allgrove syndrome). DAX-1 mutations may cluster in a syndrome with glycerol kinase deficiency with a number of other symptoms when DAX-1 is deleted together with a number of other genes.

Impaired steroidogenesis

To form cortisol, the adrenal gland requires cholesterol, which is then converted biochemically into steroid hormones. Interruptions in the delivery of cholesterol include Smith-Lemli-Opitz syndrome and abetalipoproteinemia.

Of the synthesis problems, congenital adrenal hyperplasia is the most common (in various forms: 21-hydroxylase, 17α-hydroxylase, 11β-hydroxylase and 3β-hydroxysteroid dehydrogenase), lipod CAH due to deficiency of StAR and mitochondrial DNA mutations.^[3] Some medications interfere with steroid synthesis enzymes (e.g. ketoconazole), while others accelerate the normal breakdown of hormones by the liver (e.g. rifampicin, phenytoin).^[3]

Adrenal destruction

Autoimmune adrenalitis can be a cause of Addison's disease. Autoimmune destruction of the adrenal cortex (often due to antibodies against the enzyme 21-Hydroxylase) is a common cause of Addison's in teenagers and adults. This may be isolated or in the context of autoimmune polyendocrine syndrome (APS type 1 or 2).

Adrenal destruction is also a feature of adrenoleukodystrophy (ALD), and when the adrenal glands are involved in metastasis (seeding of cancer cells from elsewhere in the body, especially lung), hemorrhage (e.g. in Waterhouse-Friderichsen syndrome or antiphospholipid syndrome), particular infections (tuberculosis,^[8] histoplasmosis, coccidioidomycosis), deposition of abnormal protein in amyloidosis.

SIGNS

Initially, the dog may be listless, or seem depressed. Many dogs are described as just seeming off, or losing the normal sparkle in their eye. Lack of appetite is a good indicator. Other symptoms include gastro-intestinal problems like vomiting and diarrhea. Pain in the hindquarters, or generalized muscle weakness such as a dog that can’t jump onto the bed or couch as he has done in the past is not uncommon. Shivering or muscle tremors may also be present. The most important thing to remember is that you know your dog better than anyone. If something seems amiss, have it checked out.

TREATMENT

Dogs with Addisons disease generally need to stay on medication for the rest of their lives.

ADDISONS SUPPORT

There are many holistic therapies you can consider, too many to list here and so I will point you towards www.addisondogs.com where the majority of this information has come from. They are very nice people and incredibly supportive. There website is full of information as well as a support group

Eyes

Heat Stroke

Hips

Undescended Testicles

Renal Failure

Toxic Substances