Health Conditions Linked to Cushing's
- Canine Cushing's Alliance
- 5 days ago
- 8 min read
Updated: 23 hours ago
Unfortunately, Cushing's disease doesn't occur in isolation. Dogs with Cushing’s are at higher risk of developing several other serious health conditions. Although getting cortisol under control decreases these risks, it may not take them away completely. This article provides an overview of the most common conditions linked to Cushing’s disease, so that you can spot warning signs early and protect your dog’s health.
Bladder Stones
About
As the name suggests, bladder stones are rock-like clumps of minerals that form in a dog’s bladder. They develop when certain minerals in urine become too concentrated and start binding together. In some cases, bladder stones obstruct the urinary tract and block the flow of urine from the body.
Connection to Cushing’s
Overproduction of cortisol increases calcium in the urine. Extra calcium in the urine promotes the formation of calcium oxalate bladder stones.
Warning Signs
Common signs of bladder stones include:
Blood in the urine, caused by stones rubbing against the bladder wall
Straining to urinate
Frequent urination in small amounts
Blood Clots
About
While blood clots are essential for stopping external wounds from bleeding, they are dangerous when they form in a vein or artery without an injury. Internal blood clots can block or restrict blood flow to organs, causing a life-threatening emergency.
Connection to Cushing’s
Elevated cortisol increases clotting factors in the bloodstream, which makes dangerous clots more likely to develop. Long-term elevation of cortisol also impairs the body’s ability to break down and remove blood clots when they form.
Warning Signs
The warning signs of a blood clot depend on where the clot is located. For a list of symptoms to look for, please see Cushing’s Disease and Blood Clot Risk, by Canine Cushing’s Alliance.
Calcinosis Cutis
About
Calcinosis cutis is a skin condition caused by calcium accumulating in or beneath the skin. Pets with this condition typically have firm bumps or patches with a gritty surface, which can be itchy and painful. The lesions sometimes develop open sores that discharge white or yellow material.
Connection to Cushing’s
The connection between Cushing’s disease and calcinosis cutis is not completely understood. However, it’s thought that high cortisol levels weaken the skin’s connective tissue, causing it to release phosphate-binding proteins that attract calcium. Lowering cortisol levels is critical to treating this condition.
Warning Signs
In the early stages, calcinosis cutis might look like a chalky white or pink skin rash, localized to one area. If cortisol is not under control, the condition will worsen and progress to firm bumps or raised patches with gritty surfaces. Many dogs with calcinosis cutis also have red or brown crust on their skin from infections beneath the lumps and patches.
Chronic Kidney Disease
About
Chronic kidney disease is a progressive and irreversible loss of kidney function, where the kidneys gradually lose the ability to filter waste from the blood, maintain fluid balance, and manage electrolytes. As a result, toxins start to build up in the bloodstream, bringing about various complications. Though there is no cure for kidney disease, a combination of diet changes, supplements, and fluid therapy are commonly used to slow progression and alleviate symptoms.
Connection to Cushing’s
Cushing’s disease harms the kidneys in several ways. Dogs with Cushing's are prone to high blood pressure and proteinuria, both of which are strongly linked to chronic kidney disease.
Proteinuria means that the kidneys are filtering protein out of the blood and into urine, instead of keeping protein in the bloodstream. The filtered protein is directly toxic to kidneys cells and tissue, causing them to become inflamed and damaged. The kidneys also become increasingly strained and weakened as they work overtime in an effort to reabsorb the lost protein.
Meanwhile, persistently high blood pressure strains and damages the delicate filtering units in the kidneys, which impairs their ability to remove toxins from the blood and regulate fluid and electrolyte balance. Over time, this loss of function can progress to chronic kidney disease.
Warning Signs
Dogs usually show no signs of kidney disease until about 65 to 75 percent of kidney function is lost. The earliest warning signs tend to be thirst and excessive urination, along with occasional decreased appetite. As the disease becomes more severe, dogs might refuse food, drink large volumes of water, urinate excessively, vomit, and have breath that smells like ammonia or urine.
Collapsed Trachea
About
The trachea, also called the windpipe, is a tube connecting the throat to the lungs. It is made up of cartilage rings that provide its tube shape and hold it open. With tracheal collapse, these cartilage rings weaken and begin to flatten in on themselves, which narrows the dog’s airway. Tracheal collapse is a chronic disease that worsens over time but can be medically managed.
Connection to Cushing’s
High cortisol levels, as seen with Cushing’s disease, weaken the trachea’s cartilage and can lead to tracheal collapse.
Warning Signs
Episodes of dry coughing, sometimes described as a goose honk, are the most common sign of a collapsing trachea. The cough may be triggered by eating or drinking, with excitement, or when something, such as a collar, puts pressure on the trachea.
Cranial Cruciate Ligament Tears
About
The cranial cruciate ligament (CCL) is a band of connective tissue that runs between the thigh bone and shin bone and keeps the knee joint stable, the same as the ACL in humans. In some dogs, the fibers in the CCL progressively weaken over time and become susceptible to tears.
Connection to Cushing’s
Excessive cortisol breaks down collagen and weakens connective tissue, which can make the CCL more likely to tear.
Warning Signs
Because a tear of the CCL causes pain, dogs will usually limp or refuse to put weight on one of their hind legs. They may also sit with an extended leg. Many dogs with a CCL tear have difficulty rising from a resting position.
Diabetes Mellitus
About
Diabetes Mellitus is a chronic condition where the pancreas doesn’t produce enough insulin or when the body doesn’t adequately respond to insulin. Insulin is the key that unlocks cells and allows glucose to move out of the blood and into liver, muscles, and fat. When insulin is insufficient or when cells don’t unlock in response to insulin, glucose accumulates in the bloodstream.
Connection to Cushing’s
Long-term overproduction of cortisol, as seen with Cushing’s disease, can bring about diabetes by causing cells to be less responsive to insulin. Over time, this leads to persistently high blood sugar levels.
For more information about Diabetes and its relation to Cushing’s disease, please see Diabetes & Cushing’s: Frequently Asked Questions.
Warning Signs
Potential signs of diabetes are excessive thirst and urination, weight loss despite increased appetite, low energy, cloudy eyes, and fruity smelling breath.
Dry Eye Sydrome
About
Dry eye, or Keratoconjunctivitis sicca, is a common condition where tear glands do not produce enough watery tears. Since tears are needed to lubricate the eyes and remove debris, dry eyes can cause a lot of pain and discomfort. Without treatment, there is a risk of scarring and infections of the cornea, potentially resulting in permanent vision loss.
Connection to Cushing’s
Cushing’s disease is one of several potential causes of dry eye in dogs. High cortisol levels impair the ability of the tear glands to produce tears.
Warning Signs
Most dogs with dry eye syndrome have redness and irritation in one or both eyes. They may paw at their eyes or hold them shut because of discomfort. You might notice yellow or green discharge that keeps coming back after cleaning.
Gallbladder Mucocele
About
A gallbladder mucocele is a potentially life-threatening condition caused by overproduction of mucus by the gallbladder lining. Because the gallbladder can’t remove the mucus, it accumulates, building up in layers. Without medical intervention, the entire gallbladder can fill with mucus and become severely enlarged, putting the dog in danger of an imminent gallbladder rupture.
Connection to Cushing’s
Research shows that dogs with Cushing’s disease are 29 times more likely to develop a gallbladder mucocele than dogs without Cushing’s disease. High amounts of cortisol are associated with reduced contraction of the gallbladder and decreased bile flow, which can trigger the gallbladder lining to produce thick mucus. Altered fat metabolism and high cholesterol can also contribute to the formation of a mucocele.
Warning Signs
In the early stages of a gallbladder mucocele, there are often no symptoms, aside from mild digestive upset or decreased appetite off and on.
In many cases, mucoceles are found during routine ultrasounds before the dog has any symptoms, highlighting the importance of preventative care.
As the condition progresses, it may cause vomiting, yellowish tinge to the gums, decreased energy, and loss of appetite.
Hypothyroidism
About
Hypothyroidism occurs when the thyroid gland is underactive. This means it doesn’t produce enough thyroid hormones, which are important for regulating metabolism, energy levels, and temperature.
Connection to Cushing’s
Many dogs with Cushing’s disease have low levels of thyroid hormones but do not have true hypothyroidism. True hypothyroidism is when the thyroid gland is destroyed or shrinks and no longer produces enough hormones. This differs from the secondary hypothyroidism caused by Cushing’s disease, where cortisol suppresses production of thyroid hormones but does not damage the gland.
Secondary hypothyroidism due to Cushing’s disease will usually improve once cortisol is under control. If hormone levels remain low despite managed cortisol, it is likely that true hypothyroidism is present and supplementation with thyroid hormones may be needed.
Warning Signs
Signs to watch out for include:
Unexplained weight gain
Tiredness and lack of desire to exercise
Excessive shedding
Thin fur
Shivering and other signs of getting cold easily
Recurrent ear infections
Muscle Atrophy and Weakness
About
Muscle atrophy is the wasting away of muscle tissue, often occurring in the hind legs and causing loss of strength.
Connection to Cushing’s
Cortisol causes loss of muscle tissue because it is a catabolic hormone. This means that it breaks down muscle proteins and inhibits repair and growth.
Warning Signs
Difficulty climbing stairs, standing up, and walking
Progressive weakness in rear limbs
Decreased activity level or unwillingness to exercise
Crossing legs while walking or standing.
Rear limbs that can no longer support body weight
Loss of coordination
Pancreatitis
About
Pancreatitis is inflammation of the pancreas, an organ responsible for producing digestive enzymes and insulin. Inflammation causes the digestive enzymes to activate prematurely, causing the pancreas to begin digesting itself. Pancreatitis can either be acute or chronic. Acute pancreatitis comes on suddenly and requires emergency care, while chronic pancreatitis is an ongoing condition.
Connection to Cushing’s
Dogs with Cushing’s disease have an increased risk of pancreatitis, though the connection isn’t fully understood. It’s thought that high triglyceride levels, common in Cushing’s dogs, can trigger pancreatitis by leading to the release of free fatty acids that damage the pancreas and cause inflammation.
Warning Signs
Vomiting, often severe and repeated
Loss of appetite
Dog in a praying position, with front legs down and rear end up
Diarrhea
Severe weakness and lack of energy
Urinary Tract Infections
About
A urinary tract infection (UTI) is a bacterial infection in any part of the urinary tract, which consists of the kidneys, bladder, ureters, and urethra. UTIs are common in dogs, especially females, and are normally treated with antibiotics.
Connection to Cushing’s
Approximately 50 percent of dogs with Cushing’s disease have a UTI at the time of diagnosis, often without showing symptoms. Excessive cortisol suppresses the immune system and weakens its ability to fight off bacteria, making it easier for infections to occur. A urine culture is important for diagnosing UTI in dogs with Cushing’s because they tend to have very diluted urine, which can hide the infection on a standard urinalysis.
Warning Signs
Increased, often unsuccessful, attempts to urinate
Strong smelling urine
Straining to urinate
Blood in the urine
Accidents in the house
Further Reading
Hypertension and Proteinuria: Frequent Complications of Cushing’s Disease in Dogs, by Dr. Mark E. Peterson