Cushing’s Disease in Dogs: Signs, Causes, and Treatment

cushing's disease in dogs

cushing's disease in dogsHave you noticed that your dog seems much more lethargic than usual?

Are you frequently finding large clumps of fur throughout your house?

Is your dog begging to be taken out far more frequently than your usual schedule allows?

If so, your four-legged friend may have Cushing’s disease. We know, as with any diagnosis for a pet, that this is a stressful, even scary time for both you and your animal. When your pet’s not feeling good, you’re not feeling good.

But in order to make the best decisions for your pet, you need to understand as much as you can about Cushing’s disease in dogs. In this post, we want to empower you by giving you that information.

Here, we’ll discuss the causes of the disease, the signs you need to look out for, diagnosis, and yes, prognosis.

While some of the information contained in this article on Cushing’s disease in dogs may be hard to hear, we want you to be prepared for the challenging choices you as an owner will need to make.

What Causes Cushing’s Disease In Dogs?

First of all, you should know that Cushing’s Disease most frequently appears in older dogs. If your dog is a larger breed, they may also be more susceptible to the disease.

However, there are 3 main types of Cushing’s Disease, all triggered by different events in a dog’s body. Let’s take a look at the 3 main causes now.

1. A Tumor In The Pituitary Gland

In the vast majority of cases — up to 90% — the disease is the result of a tumor that has developed in your dog’s pituitary gland. This gland is found right at the base of the animal’s brain. The tumor, which (as in humans) can be either benign or malignant, creates a rapid overproduction of the ACTH hormone.

This hormone is responsible for the stimulation of a dog’s adrenal glands, which are found next to the animal’s kidneys. (Hence why, as we’ll discuss in a moment, frequent urination is a common symptom of Cushing’s disease in dogs.)

This change in ACTH production means that your dog will have abnormally high (or sometimes, low) levels of cortisol in their body. Sometimes, especially if the tumor is smaller in size, veterinarians can manage the production of cortisol with medication.

If this is possible, your dog may slow down a bit and need to be taken out more often, but can otherwise live a fairly normal life.

If the tumor is larger in size, you will likely need to have a difficult conversation with your veterinarian. Larger tumors will impact the neurological function of your animal.

2. A Tumor Within The Adrenal Gland

In rare cases, the tumor that impacts the adrenal gland may actually grow within the adrenal gland itself. If you are fortunate enough to catch the tumor while it is still benign, your dog can undergo an operation to remove it.

If the tumor has already become malignant, you may once again need to make some difficult decisions.

3. A Consequence Of Medication

This is certainly one of the more difficult causes of Cushing’s disease in dogs to live with.

Sometimes, the medication we have been told to give our pets can end up making them sick.

An excessive, long-term use of dog steroids — whether injected in your pet or administered orally — has been known to cause an overproduction of cortisol. Over time, this overproduction will lead to Cushing’s Disease.

We know it’s hard to hear this, but keep in mind that you were only following the advice of a professional. Sometimes, your dog can be so sick that you have to run the risk of it developing Cushing’s disease by choosing to give them the steroids knowing the risk.

You did what you had to in order to improve your pet’s quality of life for as long as possible.

What Are The Symptoms Of Cushing’s Disease In Dogs?

Now that you know the three main causes of Cushing’s disease in dogs, let’s take a look at the most common symptoms.

Keep in mind that just because you’ve noticed some of these symptoms in your pet does not mean your dog definitely has Cushing’s. Before you jump to any conclusions and panic, schedule an appointment with a vet.

Here is a list of what you need to look for:

  • Excessive hunger and thirst
  • Heavy, frequent panting
  • A protruding, “pot-belly” stomach
  • Frequent urination
  • Excessive shedding
  • Darkening fur or patches of skin
  • Frequent insomnia
  • Rapid weight gain
  • Sudden decrease in energy levels
  • Bruises on the skin

Most of these symptoms are a direct result of the overproduction of the cortisol hormone. Cortisone makes your dog hungry, so the most prominent sign is if your dog scarfs down dinner and doesn’t seem full.

Again, these are only a few of the symptoms of Cushing’s disease in dogs. But if you notice multiple symptoms in your pet, your best bet is to take them in.

How Will My Vet Diagnose Cushing’s Disease?

So, your dog is exhibiting one or more of these symptoms, and you’ve scheduled an appointment with your vet.

How will they decide whether or not your dog has Cushing’s disease?

As you likely expected, your vet will need to conduct several types of tests to be sure. In general, there are two main types of test you can expect your pet to undergo.

The Two Main Tests For Cushing’s Disease In Dogs

First, your vet will conduct what’s called an ACTH Stimulation Examination. This will help to examine the specific levels of cortisol production in your pet’s body.

Additionally, your dog will likely receive a Low-Dose Dexamethasone Suppression Test. This test requires about 8 hours to give you the results, and the vet will need to collect multiple blood samples from your animal.

Essentially, your vet will inject your dog with synthetic cortisol, which should help to manage the production of the hormone in the animal.

Your vet will take the above-mentioned blood samples at a few different times over the duration of the injection. This way, they’ll have a clear understanding of how these hormone production levels are changing.

An Examination Of Tumor Size

Of course, if your dog has a tumor (as is likely the case) your vet will also need to run some tests to determine whether it’s benign or malignant.

To do this, your vet will take an ultrasound of your dog’s abdominal region. This will give them a clear vision of both the tumor and the adrenal glands.

A word of caution for you as the pet owner: you need to prepare for the expense of these tests. Yes, they will be quite pricey, but they can help you to catch the disease before it gets out of control.

Always be up front with your veterinarian about what you can and cannot afford to do for your dog. This is because in some cases, there may be a variety of financing options available.

While only you can decide how much you are willing to spend on the health of your pet, don’t let your current financial situation prevent you from giving your dog the help it needs.

How Can I Treat My Pet?

We know that receiving a positive diagnosis for Cushing’s Disease in dogs can be completely devastating.

Your veterinarian can provide as much professional advice as possible, but it is still you who has to make the final decisions. We know it can be an emotional time.

Luckily, there are several treatment options out there. They will vary depending on the kind of Cushing’s Disease your dog has been diagnosed with. Let’s take a look at a few of them now.

Treatment For An Adrenal Tumor

Though you may not be thrilled to hear that your dog will need to have surgery, you’re actually one of the lucky ones. A recommendation of surgery means that your vet caught the tumor before it had a chance to grow any larger.

This means your dog has a very high chance not just for survival, but to be cured of Cushing’s Disease in dogs.

As stated, this will be a bigger expense to the pet owner. If you cannot afford to give your dog the surgery it needs, or if you are nervous that it won’t survive, you have other options.

You can also elect to put your dog on the same medication that those with a pituitary tumor receive. But we do advocate for the surgery, as it provides a permanent solution for your animal.

Treatment For A Pituitary Tumor

Even though this is the most common form of Cushing’s disease in dogs, the treatment options are still the most complex.

You will need to administer multiple medications to your dog — one called trilostane, the other known as mitotane. Though you and your veterinarian will sit down and discuss how your dog needs to take these medications, it’s your responsibility to give them to your pet.

You need to understand that this is likely medication your dog will need to take for the rest of its life.

You’ll also need to closely monitor how your dog responds to these medications. Though more serious side effects are rare, they are by no means unheard of. As such, you’ll likely need to bring your dog back to the vet in the weeks following the initial doses.

Your vet will run some blood tests to ensure that your dog is responding safely and well to the medications. You may need to make some adjustments to the dosage. As with humans, much of this process is based on trial and error.

Iatrogenic (Steroid-Caused) Cushing’s

This treatment plan involves a difficult sort of catch-22. It’s possible that the only reason you gave your dog steroids in the first place was to help it to fight against another disease.

So, while you’ll need to immediately stop giving your dog steroids in order to halt the progression of Cushing’s disease in dogs, this means that the initial disease is indeed highly likely to come back.

For best results, your vet may recommend that you slowly wean your pet off of the steroids. While you may be tempted to let your dog quit “cold turkey,” doing this is incredibly dangerous.

Your dog may also need to begin taking a regimen of hormone therapy. This is because the adrenal glands may have been impacted by the steroid use. Again, this may also take a few times to get right. You’ll need to bring your pet back to the vet several times over the course of the treatment process.

What Can I Expect As A Prognosis?

Keep in mind that a medication routine will not cure the disease — it will only help your dog to manage it. They only way to really “cure” an adrenal tumor is to remove it — however, this may not always be possible.

Much of your dog’s prognosis will depend on what stage the disease had progressed to when it was caught.

It will also be influenced by the size and the position of the tumor in the animal. Be prepared to hear the worst if the tumor is both large in size and close to your pet’s brain.

If you have to put your pet down, do everything you can to make their last few days as comfortable as possible. Take lots of pictures, give your dog their favorite treats and meals, and spend as much time with them as you can.

Coming To Terms With Cushing’s Disease In Dogs

We know that this has likely been a challenging article to read. Still, we hope you’ve come away with a better understanding of Cushing’s disease in dogs.

As you can see from this post, there are treatment options available for your pet.

Don’t lose hope — instead, schedule an appointment with your vet and discuss options with your friends and family members.

The most important thing you can do? Show your dog as much love and care as possible during this difficult time.

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