Dog Health Misc.

Your Top 3 Questions on Cushing’s Disease in Dogs

I’ve quickly learned that Cushing’s disease in dogs – like many other illnesses – is complicated.  For that reason, I want to break this down in the simplest way possible.  If your dog has Cushing’s, or you suspect it, you probably have the following questions:

  1. How does Cushing’s disease in dogs develop?
  2. Is it difficult to treat Cushing’s disease in dogs?
  3. Is the disease fatal?

As a dog owner myself, I realize there are many more questions than that. However, for the sake of this post, I want to concentrate on what I think are the 3 most pressing questions.  FIRST, the disclaimers:


Disclaimer:  I am not a veterinarian. I do the best I can to provide quality content based on sound research. However, that doesn’t mean I don’t get it wrong sometimes. Please take your dog to a licensed veterinarian for the “real” diagnosis.

Affiliate:  Please note that affiliate links may appear on this page.


How Does Cushing’s Disease in Dogs Develop?

Cushing’s disease develops when the adrenal glands (located near the kidneys) create too many of the hormones that support normal functioning of the body.  The main concern is the over-production of cortisol, the “fight or flight” hormone triggered under stress.  In a healthy dog, the adrenal glands release the hormone which (among other things), tells the liver to release glucose.  In high amounts, this reaction essentially poisons the dog’s endocrine system and creates a dangerous imbalance. It’s this imbalance that creates the symptoms (see below).


Your Top 3 Questions on Cushing's Disease in Dogs










In addition, cortisol affects the dog’s blood pressure, electrolytes, immune function, and changes the way the dog metabolizes fat.

In medical terms, the disease (also called Cushing’s Syndrome) is known as hyperadrenocorticism.

When a dog is diagnosed with Cushing’s disease, it means he has a tumor that is either on the pituitary gland (below) or on the adrenal gland (below).


The details:

Cushing’s disease in dogs can present in one of three ways:


  • Pituitary tumor (small gland at the base of the brain)

This is the most common cause of Cushing’s disease in middle-aged to older dogs.  Thankfully, it’s usually benign, meaning non-cancerous. There are rare cases of malignant tumors of the pituitary gland, but an otherwise healthy dog diagnosed with Cushing’s disease stemming from the pituitary gland has an excellent prognosis.

In a small percentage of dogs (approximately 15%), the tumor grows and presses on the brain. When that occurs, the dog may experience neurological symptoms. If this happens, the outlook for the dog’s prognosis is not as good.

The larger tumors that end up causing neurological symptoms are known as macroadenomas.  These are tumors that are larger than 1 cm. The smaller tumors, or microadenomas, are generally too small to cause neurological symptoms and can usually be managed with ongoing pharmaceutical treatment.


  • Adrenal tumor (two glands located near the kidneys)

Adrenal tumors come in second-place, but still only represent a very small percentage (around 15% to 20%) of Cushing’s disease in dogs. These tumors have roughly a 50/50 chance of being benign (non cancerous), or malignant (cancerous).

I’ve read several different articles and studies on the topic, and it seems there is a divide among professionals on whether to perform surgery or not.  Surgery is risky, and there’s no guarantee that another tumor won’t pop up in the pituitary gland.

The adrenal glands are what produce the “fight or flight” response when the dog is under stress.  It doesn’t have to be labelled as “good” stress or “bad” stress. The important thing is how much stress the dog has and how it is affecting his/her endocrine system.  Adrenal glands serve an important function in maintaining balance within the body by regulating digestion, the immune system, and energy.


The following YouTube video was created by a holistic veterinarian.



Digging deeper into the adrenal glands:

The adrenal glands might be small, but they are complicated and vital to the dog’s life. There are 3 zones within the adrenal gland:

  1. Zona Glomerulosa (Outer Layer)

This layer is responsible for secreting the mineralocorticoid hormones which transport sodium and potassium through the cell walls and maintain water balance, among other things.

2. Zona Fasciculata (Middle Layer)

This layer makes up 70% of the cortex and is responsible for secreting glococorticoid hormones (cortisol and corticosterone), the fight-or-flight stress hormones.

3. Zona Reticularis (Inner Layer)

This layer produces the sex hormones including progesterone, estrogen, and androgen., these hormones work together to sustain your dog’s life

  • Iatrogenic Cushing’s disease

The third type is caused by excessive use of corticosteroid medications (prednisone is one example) over time and is rare.



  • Increased thirst and urination
  • Increased hunger
  • Pot-bellied abdomen
  • Fat redistribution to the belly
  • Skin infections
  • Loss of fur, primarily on the trunk.
  • Muscle weakness
  • Change in skin pigmentation
  • Easily bruised because of skin thinning
  • Neurologic abnormalities (circling, behavioral changes, seizures, etc.) Note: neurological abnormalities typically show once the disease has progressed. At that point, the pituitary tumor is large enough to press on the brain.


Unfortunately, like many illnesses, Cushing’s disease in dogs isn’t easily identified early on.  The veterinarian will perform a physical exam along with urinalysis and blood work.   The veterinarian can determine through a special test whether cortisol can be naturally suppressed or not.  First, the veterinarian could check the blood work for the actual cortisol level.

From there, he or she can do what’s called a “dexamethasone suppression test” by injecting a small amount into the dog.  Blood samples are taken at 4 and 8 hours post-injection. If the compound does nothing to suppress the dog’s cortisol level, Cushing’s is suspected.

“Using the word “disease” to describe Cushing’s is not considered accurate by most veterinarian professionals. Once a dog has Cushing’s, he/she has the disease for the rest of his life. In that respect, Cushing’s is really considered a “syndrome”.”


  • Is it difficult to treat Cushing’s disease in dogs?

Trilostane: This particular drug is the only drug approved by the FDA to treat both pituitary and adrenal tumors. The medication works by stopping the over-production  of cortisol from the adrenal glands.  Side effects of Trilostane could include:

  • Poor appetite
  • Vomiting
  • Low Energy
  • Diarrhea

As of 2015, the FDA began adding additional side-effect possibilities to the packaging. Some of these side-effects might include severe sodium and potassium imbalance along with things like shaking and high liver enzymes.

Unfortunately, if your dog has other conditions that affect the kidneys, liver, or heart, is isn’t safe to administer Trilostane. Up until 1994, Trilostane was used for the human version of Cushing’s. Since then, it has been banned. It is still, however, considered a good choice for dogs by some veterinarians.

I’ve searched various opinions on whether this drug is found to be useful for dogs with Cushing’s, and the reviews are mixed.  Some veterinarians will not prescribe drugs like Trilostane until they are certain without a shadow of doubt that the dog has Cushing’s disease. 

Unfortunately, symptoms can be subtly, developing slowly over time. As our dogs age, it’s easy to shrug off minor things as a simple sign of aging. If no treatment plan is offered early on, the ongoing effects of too much cortisol in the body will deteriorate the dog’s health. If nothing is done until the signs are overt and obvious, it could be too late.

Treatment for Adrenal Induced Cushing’s Disease in Dogs

Possible surgery and medication:  If the veterinarian has diagnosed a tumor on your dog’s adrenal gland, the first line of treatment might be medication in order to shrink the tumor. Once the tumor is down to an operable size, surgery is sometimes the next step. Another option for veterinarians who would rather not perform surgery on the dog (surgery can be risky) is to treat with medications on an ongoing basis, possibly for the entire life of the dog.

Lysodren (or Mitotane)

Lysoden is a chemotherapy drug used in humans. Although not approved by the FDA, veterinarians can prescribe the medication as an “off label” product. That means it is still legal to prescribe if the veterinarian has reason to believe it’s a good option. However, the FDA has not conducted or approved studies on the actual effects of the drug on dogs.  Both Lysodren and Trilostane are potent drugs that can have a variety of side-effects, some more serious than others.

In fact, a review of the administration of Trilostane for dogs with Cushing’s (published by the Canadian Veterinary Journal in April, 2018, and written by Julie Lemetaylor and Shauna Blois), suggests a high degree of controversy around this drug. While the drug does inhibit the over-production of cortisol, it can also create a certain level of toxicity in the animal.

ScienceDirect has some interesting details about this particular drug and how it works on Cushing’s disease in dogs.


Many dogs with Cushing’s disease develop a bloated or “pot-bellied” appearance.


Is Cushing’s Disease in Dogs Fatal?

There’s no cure for Cushing’s disease, but it is possible to control it for a long time. As long as the tumor remains small and manageable, your dog can go on to live many more years. What you don’t want to see is an enlarged tumor on the pituitary gland. Once that happens, it begins to affect the brain and causes a variety of neurological symptoms.

Dog’s with malignant (cancerous) adrenal tumors have a poorer outcome.  That said, if the tumor is on the adrenal gland but is benign (not cancerous), surgery could actually “cure” the disease.

That was pretty complicated and I hope I managed to get it right!

Please feel absolutely free to reach out to me with any corrections. The last thing I want to do is give anybody the wrong information.  Please remember what it says at the top of this post. I am not a veterinarian and I definitely don’t play one on TV. My goal is to provide information to help you better understand your dog’s health. The posts I write, however, are not meant to take the place of good ole legit advice from a licensed veterinarian.

So, now you’ve got a lot of information to think about. Question your veterinarian about this because it is very complicated. I had to leave a lot out, otherwise this post would go on forever.  Please come back soon! You don’t want miss some of the new posts I’ve got coming out soon.

OH..Would you do me one little favor? Could you please share this or follow me through social media? That would be awesome.



Identifying a Lump on Dog’s Neck 2018

First thing is the disclosure; I am not a veterinarian. Always see a licensed veterinarian for your dog’s health requirements.  Second disclosure is that you may find affiliate links on this page.


Identifying a Lump on Dog’s Neck

If you have discovered a lump on your dog’s neck, chances are it is a non-malignant basal cell tumor. However, as I will say over and over again, always have it checked out by a professional.

I was spending some quality time with my lab the other night, rolling my hands through the thick folds in her neck. I rubbed her chest and around both sides of her body.  As my fingers trailed back, I felt a lump. It was small, somewhat hard, and just beneath the skin.  My heart did a little lurch and (naturally) my mind went to the worst case scenario. Imagine my embarrassment when I realized it was just her nipple.  I’ll give you a second to stop laughing….

But how do you know when a lump is nothing, or when it’s something very serious? The reality is, you don’t.  Even the highest trained veterinarian can’t just glance at a lump and immediately know what it is. They probably have a much better educated guess than I do…but it still needs closer examination. “Closer examination” usually means getting a biopsy or at least aspirating the fluid to exam under a microscope. 

What I’m trying to say is not to jump to conclusions when you spot or feel a lump. A lot of times, they really are benign. If they’re not, the sooner you get your dog to the veterinarian the better.  I don’t give a lot of advice on this site because I’m not a veterinarian, but I feel pretty confident in telling you to bring your dog to the veterinarian for any suspicious lump.


Identifying a Lump on Dog's Neck 2018

Identifying a Lump on Dog’s Neck isn’t easy to do. Always contact your veterinarian for a diagnosis.

“Common” doesn’t mean benign.

For some reason, I figured the word “common” meant the lump would be non-cancerous.  That’s not always the case. Below is a list of commonly found tumors. One type – the mast cell tumor – is particularly dangerous.







  • Fatty Tumors (also known as Lipomas)

This type of lump occurs under the skin and is common in dogs. It can show up as a lump on dog’s neck, but can appear anywhere on the body. My sister’s dog had one once. It was under his jaw, at the top of his neck, and it was huge! The veterinarian did not want to lance it because he feared the dog would (essentially) bleed out. He was an old dog and ended up living with that mass until his final day.

Lipomas are normally benign (not cancerous).


  • Sebaceous Cyst

These are a little like pimples in that they occur when skin becomes blocked.  These cysts are normally found around the dog’s hair follicles or directly within the skin’s pores.  Do not lance or pinch it.  When you squeeze a pimple, you end up pushing some of the pus back inside the skin tissue where it can form another pocket.  It might even get infected. Watch for signs of redness and swelling. An infection is normally hot to the touch.  Overall, it’s not a serious thing and it won’t turn into cancer.


  • Warts

If I saw a wart on my dog, I’m pretty sure I would mistake it for something more serious. They can have a cauliflower appearance and are quite small. They can occur around a dog’s mouth, eyes, between toes, and anywhere there is more skin than fur.  It takes a lot of skill and experience to look at something like this and just know what it is.  However, it’s good to know that not EVERY lump or bump is cancer.  Warts in dogs tend to happen to young puppies, or dogs with compromised immune function.


  • Abscess

An abscess is a secondary infection caused by a wound on the dog’s body.  Bacteria invade the area which essentially disables the body’s ability to heal the original wound.  The infected site will be swollen, red, may ooze pus, and is painful.  I would contact a veterinarian for anything that even slightly resembled an infection. An abscess is a bacterial infection and will possibly need antibiotic treatment (oral and ointment, or one or the other).


  • Mast Cell Tumors

For detailed information about Mast Cell Tumors, visit my post The Truth About Mast Cell Tumor Dog Life Expectancy.

These are the most common skin cancers found on dogs. Essentially, the dog’s skin contains natural mast cells that are responsible for fighting parasitic infection, aid in repairing skin tissue, from new blood vessels, etc.  When those mast cells go awry, they become mast cell tumors. The tumors pretty much shut down the skin’s ability to do the things it is supposed to do. 

Mast cell tumors will usually spread through the dog’s body, particularly to the spleen, living, and bone marrow.




  • Basal Cell Tumor

This type of tumor develops on the outer later of skin. They are firm to the touch and are commonly found as a lump on dog’s neck or head. Although most are benign (non-cancerous), there are occasions when cancer develops and becomes malignant (spreads to other parts of the body).  Basal cell tumors (whether benign or malignant) are most successfully treated with surgery and – as always – it’s better to catch them early on. Basal cell tumors are especially common to older dog breeds such as Poodles and Cocker Spaniels.
  • Tick

I am so used to ticks that I can tell it’s a tick just by touching it. If you’re not familiar with ticks, they are disgusting parasites that chomp down onto your dog’s skin and stay there until they fill up with blood and drop off.  The biggest fear with ticks is the transmission of chronic and sometimes deadly disease.  Read my article on tick removal.

Obviously a tick is neither a tumor or cancer, but they must be removed as soon as possible. The longer a tick stays attached to your dog, the greater the risk of it transmitting disease.


  • Fibroma

A fibroma is a non-cancerous tumor common to dogs and found on limbs or pressure points.  These are also known as skin tags, cutaneous tag, polyps, or collagenous hamatoma.  VCA hospitals have a great article with all of the details regarding this growth.


  • Fibrosarcoma

Fibrosarcoma is a tumor found in the connective tissue. It is typically malignant (cancerous) although it doesn’t typically metastasize (spread to other organs in the body).  In some cases, if the integrity of the bone is compromised, the dog’s limp may need to be amputated.


  • Hemangiosarcoma

The National Canine Cancer Foundation describes these as deadly cancers that originate in the endothelium (cells that line the interior cells of blood vessels) and invade the blood vessels.


There are three types of hemangiosarcomas:

Dermal– Found on the skin

Hypodermal- Found under the skin 

Visceral- Found on the spleen, pericardium and the heart

-National Canine Cancer Foundation


  • Histiocytoma

This type of tumor looks like a raised button and is found on the dog’s head, ears or limbs. It is not usually found as a lump on dog’s neck.  The best thing about one appearing on your dog’s head is that it will be difficult (impossible) for him to lick at it and cause infection. These tumors are fast-growing tumors that are actually (usually) harmless. You’re more likely to see these on younger dogs and the tumor normally disappears over time. It’s rare for dogs to have a cancerous type of histiocytoma.


  • Injection Site Lump

This is one that might be self-explanatory and easily identified if your dog has recently had a shot.  That said, I still wouldn’t take it for granted that it’s just a side-effect of a needle injection. Tumors can appear at injection sites (vaccinations mostly) and can even appear years later.  Always have those lumps and bumps checked out by a licensed veterinarian.


Could YOU identify any of the above lumps or bumps?

Probably not.  As I mentioned above, most veterinarians won’t even hazard a guess without having a look at the cells beneath a microscope. 

If you have spotted a lump on dog’s neck, or anywhere else on the body, pay particular attention to additional symptoms like:

  • swelling
  • other sores that won’t heal
  • weight loss and low appetite
  • unusual bleeding or discharge from the lump
  • a bad smell coming from the area

Again, I can’t stress enough how important it is to bring your dog to a licensed veterinarian if you spot any unusual lump or bump. They are normal, especially as the dog ages, but you really want to catch cancerous tumors sooner rather than later.


VCA Hospitals are promoting this awareness now. Don’t adopt a “wait and see” approach because the sooner a cancerous tumor is treated, the better the outcome for the dog.


You Should Have the Following Information Before Phoning the Veterinarian.

Imagine how many people call the veterinarian to say their dog has a suspicious lump. It might help speed things along if you are able to also give the following information:

  • How big is the lump on dog’s neck? Would you say it’s the size of a pea or smaller?  Take a picture of the lump with a penny or coin next to it for size comparison.
  • Is the lump soft or hard?
  • Is it moveable?
  • What color is the lump?
  • Is their any discharge?
  • Have you noticed any unusual behavior in your dog recently (for example; no appetite, weight loss, fatigue)
  • Can you tell if the lump is painful for the dog?

At the end of the day, trying to sort out whether that lump on your dog is something to worry about is a useless venture.  Don’t panic, but don’t wait on it either. I keep saying this over and over for good reason: Make an appointment with your veterinarian and get that mysterious lump looked at.

With any luck, it will be nothing to worry about.  But if it is something, the chances of a good prognosis are much better if it’s caught early!


Hey, thanks for reading this post!  Come back often for the latest health-related posts or sign up for my newsletter so that you don’t miss a thing. Your next stop should be Chondrosarcoma in Dogs Life Expectancy, a nice complement to this post.

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Looking forward to hearing from you.  Good luck with your dog and let me know how it works out.