If you’ve been managing your dog’s Cushing’s disease and suddenly notice they’ve stopped eating, it’s understandable to feel anxious.
Cushing’s disease can be complex and unpredictable, and a loss of appetite may be your dog’s way of signaling that something isn’t quite right—whether related to the condition itself or a complication of treatment.
We outline why your dog may stop eating with Cushing’s, what you can do at home, and when it’s time to reach out to your vet.
My Dog Has Cushing’s and Is Not Eating: Why It Happens
When a dog has Cushing’s and is not eating, it may be due to medication side effects (especially from Vetoryl or Lysodren), gastrointestinal upset, secondary infections, adrenal crises, elevated cortisol levels, or disease progression.
Appetite changes often signal an imbalance in treatment, additional illness, or discomfort that needs veterinary attention.
Does Cushing’s Disease in Dogs Cause Loss of Appetite?
Cushing’s disease does not usually cause a loss of appetite. In fact, most dogs with Cushing’s disease develop an increased appetite along with increased thirst, frequent urination, panting, and a pot-bellied appearance.
If a dog with diagnosed Cushing’s disease suddenly stops eating, it may indicate that the disease has progressed, the medication needs adjustment, or another health problem has developed, such as pancreatitis, an infection, kidney disease, or gastrointestinal illness.
Because appetite loss is not a typical symptom of stable Cushing’s disease, it should always be evaluated by a veterinarian.
Dog Has Cushing’s Disease and Not Eating: Causes
1. Medication Side Effects (Vetoryl or Lysodren)
The most common treatment for Cushing’s disease is Vetoryl (trilostane) or Lysodren (mitotane), both of which aim to regulate the overproduction of cortisol.
However, if the dosage is too high or not well-tolerated, it can suppress the adrenal glands too much, leading to lethargy, nausea, vomiting, and appetite loss.
Watch for:
Sudden decrease in energy
Vomiting or diarrhea
Shaking or collapse
Refusal to eat even favorite treats
If your dog started a new medication or recently had a dose adjustment, contact your vet right away. Blood testing may be needed to reassess hormone levels.
2. Adrenal Crisis or Addisonian Reaction
In rare cases, overmedication for Cushing’s can lead to a condition called iatrogenic Addison’s disease, where cortisol levels drop dangerously low. This is considered an emergency and can cause:
Sudden inappetence
Severe vomiting or diarrhea
Weakness or collapse
Dehydration and shock-like symptoms
This reaction requires immediate veterinary intervention, often with IV fluids, electrolyte support, and steroids.
Related: Dog vomiting and not eating (Causes and when to worry)
3. Gastrointestinal Upset
Dogs with Cushing’s are more prone to gastrointestinal problems, either due to elevated cortisol levels or long-term use of steroids. Conditions like ulcers, gastritis, or pancreatitis can lead to nausea and food refusal.
Look for:
Lip licking or swallowing
Vomiting or retching
Lying in a hunched position
Disinterest in water or food
A bland diet and temporary GI-supportive medications may help, but persistent symptoms warrant vet evaluation.
4. Progression of the Disease
In advanced cases of Cushing’s, the body becomes more susceptible to muscle wasting, fatigue, liver enlargement, and immune suppression. These effects can contribute to general discomfort and loss of appetite over time.
Symptoms may include:
Weakness in the limbs
Belly distension
Lethargy and reduced interaction
Sleeping more and eating less
It’s important to track your dog’s appetite, weight, and energy levels closely as part of their ongoing care plan.
5. Infections or Concurrent Illnesses
Dogs with Cushing’s have weakened immune systems, making them more vulnerable to infections—especially of the urinary tract, skin, or respiratory system. A developing infection may cause your dog to feel unwell and stop eating.
Signs of possible infection:
Fever
Foul-smelling urine or frequent accidents
Coughing or sneezing
Skin sores or abscesses
A vet visit, urinalysis, or blood test may be required to diagnose and treat underlying infections promptly.
6. Stress or Changes in Routine
Dogs with Cushing’s may become more sensitive to environmental changes. A recent move, new pet, house guests, or even loud construction nearby could cause your dog to become anxious and skip meals.
Behavioral signs include:
Pacing or panting
Hiding or avoiding contact
Sudden disinterest in food or water
Creating a calm, consistent routine and offering meals in a quiet area can help ease their stress.
My Dog Has Cushing’s and Not Eating or Drinking
A dog with Cushing’s disease that refuses both food and water should be seen by a veterinarian as soon as possible.
This combination of symptoms is not typical of well-controlled Cushing’s disease and may indicate dehydration, medication side effects, an Addisonian crisis caused by over-treatment, pancreatitis, kidney disease, or another serious illness.
Dogs that stop drinking can become dehydrated quickly, especially if they are also vomiting or have diarrhea. Prompt veterinary assessment is important to determine the underlying cause and begin appropriate treatment.
My Dog Has Cushing’s and Not Eating and Diarrhea
A dog with Cushing’s disease that develops loss of appetite and diarrhea may have a secondary gastrointestinal illness, pancreatitis, dietary indiscretion, medication side effects, or progression of another underlying condition.
While mild digestive upset can occur occasionally, persistent diarrhea combined with refusing food should not be considered a normal part of Cushing’s disease.
If your dog also vomits, becomes lethargic, has bloody diarrhea, or shows signs of dehydration, seek veterinary care immediately, as these symptoms may require urgent treatment.
What Are the Signs of Worsening Cushing’s Disease in Dogs?
Signs of worsening Cushing’s disease in dogs occur when the condition becomes harder for the body to manage or when complications develop.
Common signs include increased thirst and urination, excessive hunger, a swollen or pot-bellied abdomen, muscle weakness, thinning skin, hair loss, panting, recurring infections, and reduced ability to tolerate exercise.
Not eating is not one of the most common signs of Cushing’s disease, as many dogs with Cushing’s have an increased appetite. However, a dog with advanced Cushing’s or complications such as infections, pancreatitis, liver problems, pain, or other illnesses may lose interest in food.
A sudden loss of appetite in a dog with Cushing’s disease should be discussed with a veterinarian.
Cushing’s Dogs Life Expectancy
The life expectancy of a dog with Cushing’s disease varies depending on the type of Cushing’s, the dog’s overall health, how early it is diagnosed, and how well it responds to treatment.
Dogs rarely die directly from Cushing’s disease itself. Instead, advanced or poorly controlled Cushing’s disease can contribute to serious complications that eventually affect quality of life.
Many dogs with well-managed Cushing’s can live for several years after diagnosis with a good quality of life.
Dogs receiving appropriate treatment and regular monitoring often experience improved symptoms and comfort.
However, untreated Cushing’s disease can increase the risk of complications such as diabetes, high blood pressure, infections, blood clots, and organ problems, which can shorten lifespan.
The goal of treatment is usually to control symptoms and maintain quality of life rather than cure the disease.
What Are the End Stages of Cushing’s in Dogs?
In the end stages of Cushing’s disease, dogs may experience a significant decline in comfort and daily function due to complications or progression of the disease.
Signs may include severe weakness, difficulty standing or walking, extreme fatigue, loss of appetite, frequent infections, uncontrolled thirst and urination, muscle loss, breathing difficulties, confusion, and reduced interest in family or normal activities.
Some dogs may develop complications affecting the kidneys, liver, pancreas, or cardiovascular system.
When a dog’s symptoms can no longer be managed comfortably and quality of life declines, the veterinarian can help to assess care options and make decisions focused on a dog’s comfort and wellbeing.
What to Do If Your Dog Has Cushing’s and Stops Eating
If your dog is stable and alert, try these steps at home:
Offer bland, soft meals such as boiled chicken, turkey, or rice
Warm food slightly to enhance smell and stimulate interest
Feed smaller meals more frequently if large meals seem overwhelming
Limit treats and rich food that may upset the stomach
Keep a symptom log including appetite, water intake, and behavior
Make sure your dog is drinking water. Dehydration can quickly worsen symptoms, especially in dogs on diuretics or steroids.
When to Call or Visit Your Vet
Reach out to your vet immediately if:
Your dog hasn’t eaten for more than 24 hours
Vomiting, diarrhea, or tremors are present
There’s sudden lethargy, shaking, or collapse
They’ve recently had a medication adjustment
You suspect an infection or adrenal crisis
Your vet may run an ACTH stimulation test, electrolyte panel, or imaging to evaluate cortisol levels and rule out secondary problems.
Read more: My dog has kennel cough and not eating (Here’s why)
Key Takeaway
If your dog has Cushing’s and is not eating, don’t ignore it. Appetite loss in these dogs can point to serious underlying issues, especially related to medication dosage, gastrointestinal distress, or secondary illness.
With careful observation, open communication with your vet, and supportive care, most cases can be managed before complications worsen.
Trust your instincts and act early—your attentiveness plays a key role in keeping your dog healthy and comfortable during their journey with Cushing’s.