Addison’s Disease


Why Should I Bring my Pet to Willows for Treatment of Addison’s Disease?

Willows is one of Europe’s leading small animal referral centres. Our state-of-the-art hospital is led by internationally renowned Specialists, to providing the highest standards of veterinary care. At Willows our team of Internal Medicine Specialists are highly experienced at the interpretation of laboratory results and work closely with the Specialist Diagnostic Imaging team who perform ultrasound or CT scans to help achieve a diagnosis.

Our Specialist are supported by our dedicated team of Nurses and clinical support staff are available 24 hours a day, every day of the year to provide the best possible care for your pet.


What is Addison’s Disease?

Addison’s disease (also known as hypoadrenocorticism), is a potentially life-threatening disorder caused by inadequate levels of hormones produced by small glands in the abdomen near to the kidneys. The adrenal glands produce two types of hormone that are essential for life:

Glucocorticoids: A natural form of cortisone (steroid). Steroids improve appetite and have effects on the function of the immune system that fights off infections. Glucocorticoids can also be used as a drug for the treatment of some diseases. Too little natural circulating cortisone is one of the components of Addison’s (too much circulating glucocorticoid also causes a problem called Cushing’s syndrome). These hormones circulate through the blood stream and have effects on cells and tissues throughout the body. Dogs or cats with insufficient levels of these hormones can become very unwell

Mineralocorticoids: Help to control the body’s concentrations of important electrolytes: sodium and potassium. Too much or too little mineralocorticoid in the body results in serious medical problems. Addison’s occurs when the body has insufficient circulating levels of glucocorticoids and/or mineralocorticoids.

What are the Common Causes Addison’s Disease?

Addison’s results when both of the adrenal glands are damaged. This most commonly occurs when the affected animal’s own immune system destroys the adrenal glands (immune mediated disease). Less common causes of Addison’s are cancers or infections that can invade and kill the adrenal gland tissues.


What are the Signs of Addison’s Disease?

The signs of Addison’s can develop quickly, usually over a few days or insidiously over a period of months. Most owners notice that their pet develops several problems including:

  • Reduced appetite
  • Lethargy and weakness
  • Vomiting
  • Diarrhoea
  • Weight loss

In severe cases some dogs will suddenly collapse and develop clinical signs of shock. Although Addison’s is not very common, it occurs most frequently in young to middle-aged female dogs. It is considered rare in cats, however it has been diagnosed in dogs and cats of all ages and of either sex (including neutered animals of both sexes). Breeds that appear to be predisposed to Addison’s include Portuguese Water Dogs, Standard Poodles and Bearded Collies, although it can affect any breed and also crossbred dogs.

How is Addison’s Disease Diagnosed?

The signs of vomiting, diarrhoea, loss of appetite, and weight loss are non-specific as many other conditions such can present similarly (i.e. stomach and intestinal disease, kidney and pancreatic disease). Further tests are therefore needed to determine the cause of these problems.

Changes that may be noted on blood tests include changes in electrolytes in the blood – an increase in potassium and a decrease in sodium are classic findings. However, these changes can also be seen with other disease processes, if Addison’s is suspected, a specific test will be recommended to confirm the diagnosis – this is called an ‘ACTH stimulation test’.


What Treatments are Available for Addison’s Disease?

Patients with Addison’s that are severely dehydrated may need to be hospitalised for initial treatment and stabilisation. Once stabilised, patients may require long-term (lifelong) treatment with hormone replacement, to substitute the missing mineralocorticoids and glucocorticoids. These drugs can be given at home in the form of tablets and injections.

The amount of medication may need to be changed over time, and regular blood tests are recommended to monitor the condition and improve the chances of good control of the disease. If dogs are stressed (e.g. due to going to boarding kennels, or because of other illness) a Vet may guide you to administer additional steroid therapy.

What can I Expect if my Pet is Treated for Addison’s Disease?

Once dogs and cats with Addison’s are correctly diagnosed and properly treated, they can live long and happy lives. Treatment is almost always successful and rewarding.

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Internal Medicine

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To assist owners in understanding more about Internal Medicine we have put together a range of information sheets to talk you through the some of the more common Medicine conditions seen and treated by our Specialists.