Addison’s is a very uncommon diagnosis of middle aged dogs and cats with females twice as likely to be affected. It is the counterpart of a much more common diagnosis – Hyperadrenocorticism or Cushings. Cushingoid animals are seen almost daily and their clinical signs are a reflection of an overproduction of hormones (specifically cortisol) by the adrenal gland (a small organ located on top of the kidneys responsible for the majority of the bodies hormone production). Addisonian animals often have very vague clinical signs as a result of a deficiency of a number of hormones. The lack of cortisol in these animals (often termed the stress hormone) reduces their ability to cope with stress and illness and as a result we may see signs such as occasional vomiting or diarrhoea, lethargy, inappetance and weakness. These animals also lack very important hormones used in the regulation of electrolyte and water balance by the kidneys. As a result they are unable to maintain their hydration, their electrolytes become unbalanced (making them feel very unwell) and waste products normally excreted by the kidneys accumulate in their blood.
Chilli presented to us in what is known as an ‘addisonian crisis’, this very closely mimics the signs and blood work changes we would see in renal failure. Chilli’s blood work began to improve and her electrolytes normalized (with good nursing care and fluid therapy) but she still appeared very depressed and was inappetant. Confirmation of her diagnosis was made with a quick blood test. The blood test aims to stimulate her adrenal glands to see what they can produce – and in her case that was not much. The lack of Cortisol was responsible for the persistence of Chilli’s depression – and within hours of supplementation she began eating and was much more responsive.
Fast forward a few weeks and Chilli is doing wonderfully with supplementation. This will have to be life long as her adrenal glands are not able to produce any of these hormones anymore. Depending on her progress we may be able to lower the dose, always bearing in mind she may have to be supplemented further in stressful situations.