If your dog has been diagnosed with Cushing’s disease — technically known as hyperadrenocorticism — you are probably grappling with a set of symptoms that can feel overwhelming: a pot-bellied appearance, relentless hunger, thinning skin, excessive thirst and urination, and gradual muscle loss. Medication is the cornerstone of Cushing’s management, but the right diet can help your dog feel better, maintain a healthier weight, and reduce the risk of secondary complications.

What Cushing’s Disease Does to Metabolism

Cushing’s disease occurs when the body produces chronically elevated levels of cortisol — the stress hormone. This excess cortisol has wide-ranging metabolic consequences:

  • Increased appetite and weight gain — cortisol drives hunger and encourages fat storage, particularly around the abdomen
  • Muscle wasting — despite weight gain, cortisol breaks down muscle protein for energy, leaving dogs visibly weaker
  • Insulin resistance — high cortisol interferes with insulin signalling, creating a situation similar to pre-diabetes; blood sugar levels become harder to regulate
  • Increased fat in the bloodstream — elevated triglycerides and cholesterol raise the risk of pancreatitis
  • Hypertension — high blood pressure occurs in a significant proportion of Cushing’s dogs, which places extra strain on the kidneys and heart
  • Increased thirst and urination — cortisol affects the kidneys’ ability to concentrate urine, so dogs drink and urinate excessively

Understanding these effects explains why dietary management focuses on several specific nutritional goals.

Low-Fat Diet to Reduce Pancreatitis Risk

One of the most serious complications of Cushing’s disease is pancreatitis — inflammation of the pancreas triggered by high levels of fat circulating in the blood. Dogs with Cushing’s already have elevated blood lipids, so adding a high-fat diet on top dramatically increases this risk.

A diet low in fat — ideally below 10–12% fat on a dry matter basis — helps keep blood triglycerides in check and reduces the burden on the pancreas. Practical steps include:

  • Choosing a commercial low-fat therapeutic or maintenance food
  • Avoiding fatty treats such as cheese, meat offcuts, or processed snacks
  • Trimming visible fat from any cooked meat used as a food topper
  • Replacing high-fat chews with low-calorie alternatives like carrot sticks or cucumber

Moderate, High-Quality Protein to Combat Muscle Loss

Because Cushing’s actively breaks down muscle tissue, it is important not to restrict protein unnecessarily. A moderate to moderately high level of high-quality, easily digestible protein helps preserve lean body mass. Good sources include:

  • Lean chicken, turkey, or white fish
  • Egg (highly digestible and nutrient-dense)
  • Commercially prepared foods using named protein sources (chicken meal, salmon, etc.)

Avoid protein sources that are also high in fat — lamb, pork belly, and some red meats may provide good protein but come with a high-fat cost that is counterproductive for Cushing’s dogs.

Low-Sodium Food if Hypertension Is Present

If your vet has confirmed high blood pressure as part of your dog’s Cushing’s profile, reducing sodium intake becomes an additional priority. Excess sodium contributes to fluid retention and worsens hypertension. Look for:

  • Foods labelled as low-sodium or formulated for heart or kidney conditions (these are typically sodium-restricted)
  • Avoiding processed human foods, deli meats, and salty snacks entirely
  • Checking the sodium content of any dental chews or treats — many are surprisingly salty

Your vet may be managing blood pressure with medication as well; diet works alongside this, not instead of it.

Avoiding High-Glycaemic Foods

Because Cushing’s dogs have impaired insulin signalling — and some go on to develop diabetes mellitus as a complication — keeping blood sugar stable is important. High-glycaemic foods cause rapid glucose spikes that a cortisol-disrupted system struggles to handle. Foods to moderate or avoid include:

  • White rice and white bread in large quantities
  • High-sugar treats and biscuits
  • Corn syrup or sweetened additives

Lower glycaemic options like sweet potato, oats, or lentils (in moderate amounts) are better carbohydrate sources for these dogs. If your dog has developed concurrent diabetes, consult your vet for a more specific diet plan — the two conditions together require careful dietary calibration.

Managing the Insatiable Appetite

One of the most challenging aspects of Cushing’s for owners is the relentless hunger. Cortisol genuinely makes dogs feel hungry, and this is not simply greed — it is a hormonal drive. Strategies to manage this without overfeeding include:

  • Adding low-calorie bulk: cooked green beans, cucumber, courgette, and other non-starchy vegetables can significantly increase meal volume without adding meaningful calories
  • Feeding smaller, more frequent meals: three or four smaller meals per day can reduce the intensity of hunger between feeds
  • Using slow feeders or food puzzles: these extend meal time and create a greater sense of satisfaction
  • Sticking firmly to portion sizes: it can feel cruel to deny a hungry dog, but consistent portions are essential for weight management

Weight gain worsens all of the metabolic problems associated with Cushing’s, so maintaining or gradually reducing body weight (if your dog is overweight) should be a clear goal.

Supporting the Whole Body

Beyond the core dietary goals, a few additional considerations are worth discussing with your vet:

  • Omega-3 fatty acids: despite the general low-fat requirement, anti-inflammatory omega-3s from marine fish oil (EPA/DHA) provide targeted benefits — they support skin and coat health (often affected in Cushing’s dogs) and have mild anti-inflammatory properties. Use a measured dose appropriate to your dog’s weight.
  • Antioxidants: Cushing’s is associated with oxidative stress. Diets rich in antioxidant vitamins (E, C, beta-carotene) may provide some protection. Many commercial foods already include these; ask your vet before adding supplements on top.
  • Hydration: the excessive urination typical of Cushing’s can lead to mild dehydration. Ensure fresh water is always available, and consider wet food or adding water to kibble to support intake.

Monitoring Your Dog’s Condition

Because Cushing’s is a progressive endocrine condition, regular vet check-ins are essential. Diet and medication doses may need to be adjusted over time as the disease evolves. Key things to monitor at home include:

  • Body weight — weigh your dog every 1–2 weeks; unexpected gain or loss should be reported to your vet
  • Muscle condition — notice if your dog seems weaker, struggles with stairs, or loses topline muscle
  • Appetite and thirst — these can fluctuate with medication levels
  • Coat and skin condition — a good diet helps here, but worsening symptoms may indicate disease progression

What to Avoid

  • High-fat foods and treats — pancreatitis risk is real and serious
  • High-sodium foods — problematic if hypertension is present
  • Large carbohydrate-heavy meals — these destabilise blood glucose
  • Ad-lib feeding — portion control is essential given the cortisol-driven hunger
  • Sudden diet changes — transition any new food slowly over 2–3 weeks to avoid GI upset

The Bigger Picture

Dietary management of Cushing’s disease is one piece of a larger puzzle. Medication — typically trilostane or mitotane — is the primary tool for controlling cortisol levels. Diet supports the treatment by reducing secondary risks (pancreatitis, weight gain, diabetes), supporting muscle maintenance, and helping your dog feel as comfortable as possible between vet visits.

If your dog has recently been diagnosed or you are struggling to find the right balance of food and medication management, contact us — our nutrition team can help you build a practical feeding plan tailored to your dog’s individual profile.

Always manage Cushing’s disease under veterinary supervision. Dietary changes are supportive and should complement — not replace — appropriate veterinary diagnosis and medical treatment.