Diet for Dogs with Cushing's Disease: What to Feed (and What to Avoid)

Diet won't cure your dog's Cushing's disease. But what you feed day-to-day has a real impact on how well they manage the condition — and some common choices actively make things worse.

Cushing's is a metabolic disease. It disrupts fat storage, blood sugar regulation, muscle mass, and the immune system. That means what goes in the bowl matters more for a Cushing's dog than it does for a healthy one.

Here's the practical guide — what to avoid, what to feed, how much, and how diet fits into the bigger picture of Cushing's management.

Why Cushing's Disease Changes What Your Dog Should Eat

Cushing's disease causes chronically elevated cortisol. That single hormonal imbalance creates a cascade of downstream effects that directly affect how your dog processes food:

• Elevated triglycerides and cholesterol — Cushing's dogs have disrupted fat metabolism. High-fat diets add fuel to this fire.
• Insulin resistance — Cortisol competes with insulin. A diet heavy in simple carbohydrates can worsen blood sugar instability.
• Muscle wasting — Cortisol is catabolic, meaning it breaks down muscle tissue. Adequate, high-quality protein helps counteract this.
• Increased appetite — Cushing's dogs are often food-obsessed and prone to weight gain, particularly around the abdomen.
• Immune suppression — Chronic cortisol elevation blunts immune function, making Cushing's dogs more vulnerable to infections including UTIs.
• Elevated blood pressure — Cortisol raises both heart rate and blood pressure, so hypertension is common in Cushing's dogs and is worsened by high-sodium diets.
• Oxidative stress — Chronically high cortisol is associated with increased oxidative stress, which is why antioxidant content matters more than usual.

A diet that accounts for these specific vulnerabilities supports the whole management protocol — not just one symptom.

Start With Calories, Not Ingredients

Before choosing a food, work out how much of it your dog should be eating. Body weight should be managed as close to your dog's ideal body weight as possible, and for most Cushing's dogs that means eating less than they would like to.

The first step is to determine the number of calories needed to reach ideal body weight, based on your dog's age, breed and body condition score. You can get a rough estimate of ideal body weight using PetMD's healthy weight tool and a suggested daily caloric intake from Vet Calculators.

Treat both as starting points only. They need refining based on how your dog actually responds and on your veterinarian's advice — any change in diet or exercise should be discussed with your vet first.

Reading a Label: The AAFCO Starting Point

Once you have a calorie target, the next question is what those calories are made of. A reasonable baseline is the profile set by the American Association of Feed Control Officials (AAFCO) for adult maintenance — not the growth or reproduction profile, which will invariably be too high in fat and carbohydrates for a Cushing's dog.

On a commercial food, look for those words — "adult" and "maintenance" — in the AAFCO statement on the label, near the Guaranteed Analysis panel.

The important caveat: AAFCO sets minimum and sometimes maximum thresholds, nothing more. Two foods can both meet it and be very different. So the AAFCO statement gets you a shortlist; the criteria below are how you choose within it.

What to Avoid Feeding a Cushing's Dog

High-fat foods

This is the most important one. Cushing's dogs already have elevated triglycerides and disrupted fat metabolism. High-fat diets — including fatty cuts of meat, most table scraps, and high-fat commercial treats — add directly to this metabolic burden.

There is also a mechanistic reason to go lower still. Cortisol and the other adrenal steroids are synthesised from cholesterol and its metabolites, so a diet low in cholesterol limits the raw material available for making them. AAFCO caps fat at 12% on a dry-matter basis but doesn't distinguish saturated from unsaturated fat and sets no cholesterol level at all. If you're formulating yourself, you can improve on it: favour unsaturated, low-cholesterol fats and push total fat below the 12% ceiling rather than up against it.

High-sodium foods

Many Cushing's dogs have elevated blood pressure. Sodium makes this worse. Avoid deli meats, heavily processed treats, and most commercial dog treats, which are often surprisingly high in sodium. Read labels: look for less than 100mg sodium per 100 calories.

Simple carbohydrates and high-glycemic ingredients

Because Cushing's can cause insulin resistance, diets heavy in corn, white rice, white potato, and refined grains can worsen blood sugar management. Many commercial kibbles lead with these ingredients. Check the first three ingredients on any kibble you're considering.

Flaxseed oil — not the same as lignans

Worth calling out specifically. Some owners confuse flaxseed oil with flaxseed hull lignans, but they're not interchangeable. The SDG lignans that help manage Cushing's are concentrated in the hull of the flaxseed — not in the oil. Flaxseed oil has very low lignan content, and its fat profile can actually raise triglycerides in Cushing's dogs. If you're giving lignans for Cushing's management, use hull-based SDG lignans, not oil.

For a full list of lignan options, see our lignans for dogs collection.

Treats and table scraps

Cushing's dogs are often intensely food-motivated because elevated cortisol drives appetite. It's easy to over-treat. Beyond the fat and sugar content itself, treats and scraps quietly undo the calorie maths you just did — unless you account for them and take the calories back out of meals.

Replace high-fat or high-sodium treats with low-fat options: plain cooked chicken, green beans, blueberries, or carrot pieces.

What to Feed a Dog with Cushing's Disease

Lean, highly-digestible protein

Protein is the most important macronutrient for a Cushing's dog. Cortisol breaks down muscle mass over time, so adequate protein helps counteract this. Prioritize:

• Chicken breast or turkey (skinless)
• White fish (cod, tilapia, flounder)
• Lean beef or venison
• Eggs (whole eggs or egg whites — both are well-tolerated)
• Organ meats in moderation (liver, kidney) — nutrient-dense but should be limited to 10–15% of the diet

Digestibility is the thing to optimise for, not just protein percentage. Muscle meat, organ meat and egg whites are the most digestible sources. Plant-based proteins such as soy and pea protein digest at roughly 54–75% and should be limited or avoided.

On a label, look for foods where a named protein is the first ingredient. "Chicken" is better than "chicken meal," which is better than "poultry by-products."

Complex carbohydrates over simple ones

Cushing's dogs do better with slow-digesting carbohydrates that don't spike blood sugar. Good options:

• Sweet potato
• Oats
• Brown rice (in moderation — lower glycemic than white)
• Barley
• Lentils

Moderate fiber

Fiber helps with weight management, blood sugar regulation, and digestive health, and soluble fiber can reduce cholesterol levels. It also feeds the gut microbiome — which matters directly if your dog is on lignans, for reasons covered below. Aim for 5–17% crude fiber on a dry-matter basis. Easy additions:

• Green beans (a popular low-calorie filler if your dog is overweight)
• Carrots
• Broccoli (in moderation)
• Pumpkin (plain canned pumpkin — not pie filling)
• Leafy greens: spinach, kale, bok choy

Antioxidants

Because chronically high cortisol drives oxidative stress, preference should be given to ingredients and supplements high in antioxidants — beta-carotene, alpha-tocopherol (vitamin E), methionine, selenium and vitamin C among them.

Omega-3 fatty acids

Omega-3s support inflammation management, cardiovascular health, coat quality, and joint function — and help reduce triglycerides and blood fat levels, which is the specific problem in a Cushing's dog. The best source for dogs is fish oil, not flaxseed oil (see above). Look for a product formulated for dogs with specified EPA/DHA levels. Sardines packed in water are also an easy whole-food source.

Liver support

Your veterinarian may also suggest supporting liver function, particularly if your dog is on trilostane. Milk thistle and SAMe are the two most commonly used.

Probiotic support

If your dog is on SDG lignans for Cushing's management, probiotics have a direct benefit: the active compounds in SDG lignans are converted by gut bacteria into the metabolites that interact with your dog's hormonal system. A healthier gut microbiome means more efficient lignan conversion. Plain yogurt with live active cultures is a simple way to support this, or use a dog-formulated probiotic supplement.

For a dog-specific option, see our K9 Select Probiotic.

Commercial Food vs. Home-Cooked: What Works for Cushing's Dogs

There's no commercial diet specifically formulated for Cushing's disease in dogs. If you're using kibble, the key criteria:

• Named protein (chicken, turkey, salmon) as the first ingredient
• Fat content under 12% dry matter
• Crude fiber in the 5–17% range
• Low sodium
• No corn syrup, excessive salt, or artificial preservatives
• An AAFCO "adult maintenance" statement

Grain-free isn't automatically better for Cushing's dogs, and some grain-free diets are higher in fat and caloric density. Overall nutrient composition matters more than the grain/grain-free distinction.

Home-cooked diets give you the most control, but they require careful balancing to ensure completeness over time. If you're preparing meals at home, work with your vet or a veterinary nutritionist to make sure you're meeting your dog's full nutritional needs — particularly calcium balance if you're not including bones or bone meal.

Many owners find a middle ground: a quality commercial food as the base, with fresh protein, vegetables, and targeted supplements added on top.

When to Feed

Two meals a day is the usual recommendation for an active adult dog, with the total across both meals staying inside the daily calorie target. The right frequency varies from dog to dog and should be settled with your veterinarian.

Timing relative to exercise matters more than most owners expect. Dogs perform best using energy from meals already digested, and performance drops if a dog is exercised too soon after eating or fed too close to sleep. Where practical, aim to feed 6–8 hours before exercise.

Exercise itself is not optional for a Cushing's dog — it's one of the more effective things you can do about insulin resistance, and it works alongside the diet rather than as an alternative to it.

How Diet and Supplements Work Together

Diet and lignans work best as a system, not in isolation. A lower-fat, high-protein diet with adequate fiber creates a metabolic environment that supports what lignans and melatonin are doing at the hormonal level. Think of diet as reducing the background noise — the metabolic stress from poor nutrition — so the supplement protocol can work more efficiently.

Nutritional therapy runs alongside medical therapy, not in place of it. Together they reduce the building blocks available for cortisol production, and over time lower circulating corticosteroid levels reduce the visible signs of the disease.

Many owners managing Cushing's naturally with lignans and melatonin report that diet changes in combination with supplementation produced noticeably better results than either approach alone.

Frequently Asked Questions

What is the best diet for a dog with Cushing's disease?

The best diet for a Cushing's dog is high in lean, digestible protein; moderate in complex carbohydrates; low in fat (under 12% dry matter); moderate in fiber (5–17%); and low in sodium. Fresh, whole foods — lean meats, vegetables, and eggs — are generally better than processed commercial foods, which are often high in fat, sodium, and simple carbohydrates.

How many calories should a dog with Cushing's eat?

There's no single number — it depends on your dog's ideal body weight, age, breed and body condition score, not their current weight. Use a caloric requirement calculator as a starting point, then adjust based on how your dog responds and on your vet's guidance. Because Cushing's drives appetite and abdominal weight gain, most Cushing's dogs need their intake controlled more tightly than a healthy dog of the same size.

Can diet help manage Cushing's disease in dogs?

Yes, significantly. While diet alone won't cure Cushing's, the right nutrition directly supports several of the metabolic disruptions the disease causes: elevated triglycerides, insulin resistance, muscle wasting, and immune suppression. A well-chosen diet reduces the overall burden on your dog's system and makes other treatments — both pharmaceutical and natural — work more effectively.

Should a dog with Cushing's eat a low-fat diet?

Yes. Cushing's disrupts fat metabolism and raises triglyceride levels, and the adrenal steroids that are already too high are built from cholesterol. A low-fat, low-cholesterol diet (under 12% fat on a dry-matter basis) reduces the load on an already stressed metabolic system. This is one of the most consistent dietary recommendations across both conventional and integrative veterinary guidance for Cushing's dogs.

Is grain-free food better for Cushing's dogs?

Not necessarily. Grain-free diets aren't automatically better for Cushing's — some are actually higher in fat and caloric density than grain-inclusive options. What matters for Cushing's is overall composition: fat content, protein quality, fiber levels, and sodium. Evaluate each food on those criteria rather than the grain-free label.

Can I feed my Cushing's dog raw food?

Some owners of Cushing's dogs do feed raw diets and report positive results — particularly improved coat quality and energy. The benefit is primarily the high protein content and absence of fillers, preservatives, and simple carbohydrates. The main concerns with raw diets are bacterial contamination risk (which matters more in immune-suppressed dogs like those with Cushing's) and ensuring nutritional completeness. If you're considering raw feeding for your Cushing's dog, discuss it with your vet and introduce it gradually.

What foods should I avoid giving a dog with Cushing's?

Avoid high-fat foods, high-sodium foods, simple carbohydrates (white rice, corn, white potato), table scraps, and most commercial dog treats. Also avoid flaxseed oil — it has very low lignan content and can raise triglycerides. Stick to low-fat, whole-food options for treats: plain cooked chicken, green beans, blueberries, carrot pieces.

How does diet interact with lignans for Cushing's dogs?

Diet and SDG lignans work together. Lignans help regulate the hormonal pathway that's overactive in Cushing's, while diet reduces the metabolic stress that chronic cortisol elevation causes. Probiotics specifically support lignans — gut bacteria convert SDG into the active metabolites that interact with your dog's endocrine system. Yogurt with live cultures or a probiotic supplement can improve lignan effectiveness.

Sources

1. VCA Animal Hospitals — Cushing's Disease in Dogs
2. American Kennel Club — Cushing's Disease in Dogs
3. PetMD — Cushing's Disease in Dogs: Symptoms & Diagnosis
4. Merck Veterinary Manual — Pituitary-Dependent Hyperadrenocorticism in Animals
5. Tufts University Cummings School of Veterinary Medicine — Cushing's Disease in Dogs
6. University of Zurich — Serum lipid profiles in dogs with hyperadrenocorticism
7. AAFCO — Understanding Pet Food Labels
8. American Kennel Club — Getting the Overweight Dog in Shape