Addison’s disease is a rare hormonal disorder which affects dogs, cats, and humans. If a dog has Addison’s disease, this means that their adrenal glands are failing to produce important hormones responsible for regulating some of their key bodily processes.
Addison’s disease is a serious condition and can be fatal if left untreated. However, it can usually be controlled successfully with the right treatment. Most dogs with appropriately-treated Addison’s disease will have a normal lifespan.
What is Addison’s Disease?
Dogs have two adrenal glands, one next to each kidney. They produce two important hormones – cortisone and aldosterone. Cortisone helps your dog’s body to cope with stress, while aldosterone controls the balance of water and electrolytes in their body. The adrenal glands also work in tandem with the pituitary gland and hypothalamus in the brain by producing hormones to help control various systems including digestion and immunity. If your dog has Addison’s disease, their adrenal glands don’t produce these hormones and problems occur with their organs and bodily systems.
Why Do Dogs Get Addison’s Disease?
For most dogs with Addison’s disease, there is no clear reason why they developed the condition. It’s thought that an autoimmune problem is the root cause of most cases.
Damaged or destroyed adrenal glands can also cause Addison’s disease. If your dog has a tumor or hemorrhage in or around their kidneys, this could increase their likelihood of getting Addison’s disease. Occasionally, adrenolytic medicines can cause the condition.3
Symptoms To Look Out For
If your dog has Addison’s disease, they will probably seem weak and generally unwell. They may have vomiting and diarrhea and go off their food, leading to rapid weight loss. This can make them dehydrated, so increased thirst is another key symptom to look out for.
Addison’s disease can also make your dog shake, and you may notice that their body feels cooler than usual. This is easiest to detect by feeling their ears. If you take your dog for a check-up, the vet may notice an abnormally low heart rate. It’s normal for symptoms of Addison’s disease to come and go, so your dog may not appear unwell all of the time.4
What Is An Addisonian Crisis?
If your dog’s Addison disease symptoms become acute and make them seriously unwell; this is known as an Addisonian crisis. When this happens, they are likely to have severe vomiting and diarrhea, collapse, or go into shock. An Addisonian crisis is a life-threatening event. They will need to be hospitalized and receive intensive treatment. If your dog shows any of the symptoms of an Addisonian crisis, you should contact your vet immediately, even if they don’t have a diagnosis of Addison’s disease. An Addisonian crisis is often the reason that a dog gets diagnosed with the condition.5
If an Addisonian crisis is suspected, your dog’s vet will carry out tests to confirm the diagnosis. They will use blood work, biochemistry tests, and a urinalysis to check for signs of Addison’s disease and rule out other conditions with similar symptoms. If your dog has the condition, it’s likely that these tests will detect a low concentration of urine and high levels of potassium, sodium, chloride, calcium, and urea in their blood.
The vet will also carry out a test called an adrenocorticotropic hormone (ACTH) test stimulation test. The test involves introducing a synthetic hormone called ACTH into your dog’s system and monitoring their cortisol levels. This allows the vet to tell if your dog’s adrenal glands are functioning normally.6
How Is Addison’s Disease Treated?
If your dog has Addison’s disease, they will need hormone replacement medications. These are usually given as a monthly shot by the vet along with a daily dose of steroids at home. Most dogs with Addison’s disease will need to continue this treatment for the rest of their lives. It will probably take some time to find the correct dosage of medication to keep your dog healthy. In the weeks following their diagnosis, your dog will need to visit their vet regularly to have their hormone and electrolyte levels checked, and their medication dosage adjusted accordingly.7
Are Some Dogs At Higher Risk?
Any dog can get Addison’s disease. However, there are some known risk factors. The condition is most commonly in female dogs, and the average age at diagnosis is at four years old.
Addison’s disease can occur in pure and mixed-breed dogs. However, some breeds are more prone than others. Poodles, west highland terriers, collies, and Portuguese water dogs are all genetically predisposed to Addison’s disease.8
Primary vs. Secondary Addison’s Disease
If your dog has Addison’s disease, the vet may tell you whether they have the primary or secondary form of the condition. Primary Addison’s disease is idiopathic, which means the cause is unknown.
Secondary Addison’s disease is less common, and its causes can vary depending.
Addison’s Disease and Stress
Addison’s disease can affect your dog’s ability to cope with stress. In stressful situations, their adrenal glands produce the hormone cortisol to help them withstand it. If they have Addison’s disease, they are unable to synthesize enough cortisol for them to cope. This often means that their symptoms get worse at times of stress or strain. For example, their Addison’s disease may flare up if they are boarded away from home.
Preventing Addison’s Disease
There is no way to prevent Addison’s disease. The exception to this is if your dog has a condition called Cushing’s disease, which is opposite to Addison’s disease in that the body overproduces cortisol. Accidentally taking too much medication for Cushing’s disease can cause an Addisonian crisis. It’s important to make sure that any Cushing’s disease medication is shut away where your dog doesn’t have access to it.