Addison’s disease or hypocorticism is a condition affecting the adrenal glands. These glands are located in front of the kidneys and consist of an outer part, the cortex, and an inner part, the medulla.
The adrenal glands are closely associated with two other glands present in the brain, the hypothalamus and the pituitary gland, thus constituting the corticotropic axis. Thus, the production of hormone by the hypothalamus influences the pituitary which, itself, produces a specific hormone, ACTH. This hormone stimulates, among other things, the production by the adrenal glands of a “natural cortisone”, cortisol.
Addison’s Disease is defined by insufficient secretion of cortisol, called hypocorticism.
Which dogs are the most exposed?
The vast majority of dogs with this disease are young adults (between 4 and 6 years old) of the female sex. Pure breeds are more particularly affected such as the Poodle, the Great Dane, the Rottweiler, the Westie or the Bearded Collie.
These criteria, although not systematic, can already guide the suspicion of this affection.
What are the causes ?
When we talk about Addison’s disease in dogs, it is usually primary hypocorticism.
Among the most frequent causes, we can cite a defect in the development of the adrenal gland (genetic hypothesis) or its destruction (immune causes, hemorrhages, infections, tumors).
There is nevertheless a secondary hypocorticism associated, for example, with a disease of the pituitary gland, which no longer stimulates the functioning of the adrenals, or with the use of drugs, in particular those used in the treatment of hypercorticism also called Disease of Cushing.
What are the warning signs?
There are two forms of Addison’s disease.
In the acute form, the possible signs are numerous and sudden. There is shock, vomiting, dehydration, loss of appetite, lower than normal body temperature, painful abdomen, and muscle weakness. The dog does not usually get up anymore.
In the chronic form, lethargic state, decreased appetite, regular vomiting and increased water consumption are observed.
These symptoms should arouse great mistrust and the setting up of additional examinations in parallel with intensive care allowing the recovery of the general condition of the subject.
How should we manage this condition?
The symptoms evoked are not sufficient to establish a definite diagnosis.
A blood test should be performed to show an increase in certain parameters such as urea and potassium, or a drop in sodium levels, as well as sometimes a change in the blood count (anemia, increased blood pressure). number of white blood cells). Other tests, such as an x-ray of the heart, an ultrasound exam (revealing abnormally small adrenal glands) or an EKG, may provide additional information.
But only a specific test, called an ACTH stimulation test, will validate the supposed diagnosis.
During these examinations, it is naturally necessary to restore the general condition of the patient as quickly as possible by massively infusing him to fight against dehydration and by providing him with the two types of corticosteroids which his body is deprived of due to the failure of the adrenals. .
The causes of the disease being, most of the time, irreversible, a permanent treatment will be instituted as soon as the animal comes out of its hypocorticism “crisis” and the scheduled regular blood checks.
Due to the absence of specific clinical signs and the rarity of this condition, Addison’s disease is regularly underdiagnosed or confused with other diseases, especially kidney, with which it shares certain manifestations.
The symptoms described above, or even only abnormal fatigue, should prompt you to consult your veterinarian as soon as possible.
Only emergency care and treatment adapted to the severity of the symptoms can ensure the survival of the animal.