Inflammaging in Dogs: What Chronic Inflammation Means for Healthy Aging

By Caroline Buck, Co-founder of Petaluma

Most of us notice the outward signs of a dog getting older, like a gray muzzle or a slower start on morning walks. Many of the changes that come with age happen out of sight. One of them is a slow, low-grade rise in inflammation throughout the body, which scientists call inflammaging.

In people, inflammaging is one of the most studied ideas in aging research, and it has been tied to many of the most common diseases of later life. Research on inflammaging in dogs is much newer, and it is easy to find bold claims online that run ahead of the evidence. So what is inflammaging in dogs, how do vets measure inflammation today, and what can you do about it? This guide covers what the canine research shows, what decades of human research add, and the everyday factors you can control: diet, weight, and stress.

What is inflammaging in dogs?

Inflammaging is a slow, body-wide rise in chronic inflammation that happens as animals age. Italian immunologist Claudio Franceschi coined the term in a 2000 paper on the aging immune system. It describes a quiet, constant background of inflammation that builds over years.

It helps to separate two kinds of inflammation. Acute inflammation is the fast, short response you can see: the swelling, heat, and redness around a cut or a sprained paw. It switches on to fight infection or repair damage, then switches off. Chronic inflammation is low-grade and long-lasting. It usually has no visible signs, and over years it can wear on tissues throughout the body.

The evidence that dogs experience inflammaging

Two studies give us the clearest picture so far. In a 10-year study of 80 dogs published in 2018, researchers at the Waltham Petcare Science Institute followed the same dogs from adulthood to the end of life. Levels of CRP, a protein the liver releases during inflammation, rose by about 30% as the dogs aged.

In 2024, the Dog Aging Project published a pilot study of 47 healthy companion dogs. Older dogs had higher levels of three cytokines, the signaling molecules immune cells use to switch inflammation on: IL-6, IL-8, and TNF-α. The authors designed it as a small first step toward a larger study, so the details will sharpen as more data comes in.

How vets use inflammation markers in dogs today

Today, vets use inflammation markers mainly to spot and track active illness. The most common one is C-reactive protein (CRP), and a CRP test for dogs is available through veterinary reference labs and some in-clinic analyzers. A 2022 review of CRP as a diagnostic marker in dogs explains why it is so useful.

CRP responds quickly. It starts to climb about 4 to 6 hours after an infection, injury, or surgery, and it peaks at 24 to 48 hours. At its peak it can reach 50 to 100 times its normal level. Once the cause is treated, it falls fast, losing half its level in about 19 hours.

What a CRP test cannot tell you

CRP shows that inflammation is present, but it does not say where it comes from or what is causing it. In one study cited in the review, only 22% of 147 dogs with very high CRP had a confirmed bacterial infection. Some conditions, including degenerative joint disease, may not raise CRP at all. Hard exercise can raise it too, and sled dogs showed a 10-fold rise after a 557 km race.

For these reasons, vets read CRP alongside a physical exam and other bloodwork. In people, doctors use a sensitive version of the test to sort healthy adults into lower and higher heart risk groups. Researchers have not yet defined a similar range for low-grade, age-related inflammation in healthy dogs. That makes CRP a well-established tool for illness in dogs, and an open research question for healthy aging.

What human research shows about inflammation and aging

Human research links chronic inflammation to most of the major diseases of aging, and the evidence is deep. A 2019 review in Nature Medicine estimated that more than half of all deaths worldwide come from diseases tied to chronic inflammation, including heart disease, stroke, cancer, and diabetes.

The same review named the everyday drivers of chronic inflammation in people. They include highly processed, low-fiber diets, excess body fat, physical inactivity, poor sleep, chronic stress, and adversity early in life. Many of these have a clear counterpart in a dog's life.

Eating patterns and inflammation

Researchers score the inflammatory potential of a person's diet with tools such as the Dietary Inflammatory Index. Diets rich in fiber, vegetables, legumes, whole grains, and omega-3 fats score as anti-inflammatory. Diets heavy in processed foods, refined starches, and saturated fat score as pro-inflammatory.

Those scores track with long-term health. A 2019 analysis of 12 large studies found that people eating the most inflammatory diets had 23% higher death rates from all causes than people eating the least inflammatory diets.

Diet changes can also move inflammation markers quickly. In the 2018 EVADE CAD trial, 100 adults with heart disease ate either a plant-based vegan diet or the diet recommended by the American Heart Association. After eight weeks, the plant-based group had 32% lower high-sensitivity CRP than the AHA group.

These are human findings, and dogs are not small people. Dogs have their own nutrient needs and their own metabolism. Still, the human research shows how much daily habits can shape inflammation over a lifetime, and it gives canine researchers a roadmap.

Diet and inflammation in dogs

Diet very likely matters for inflammation in dogs, but the canine research is still thin. The best-studied nutrients are the long-chain omega-3 fats EPA and DHA. A 2022 meta-analysis of diets and supplements for arthritis concluded that the evidence supports omega-3s for managing osteoarthritis in dogs and cats.

Whole-diet research is much harder to find. One 2022 trial fed 16 healthy dogs a whole-food diet and an extruded dry food for 67 days each. CRP and the other inflammation markers measured did not differ between the two diets. The study was funded by the company that made the whole-food diet, and the authors called it exploratory.

As far as we can find, no published study has yet measured CRP in dogs fed a plant-based diet. The human research gives good reasons to ask the question. Fiber, legumes, whole grains, and omega-3s are central to the anti-inflammatory eating patterns studied in people. Dogs are omnivores, and a complete and balanced dog food can include all of these.

What you can do today

• Feed a complete and balanced food: Look for an AAFCO complete and balanced statement so your dog gets every essential nutrient.
• Include preformed omega-3s: EPA and DHA from fish or algae have the strongest canine evidence for joint health.
• Keep treats in proportion: Treats should stay under about 10% of daily calories, as our guide to the 10% rule explains.
• Talk to your vet before supplements: Omega-3 doses for joint disease are higher than what a typical food provides, so your vet can help you choose a safe amount.

At Petaluma, our recipes are formulated by veterinary nutritionists, and we follow this research closely. We believe diet will prove to be one of the most useful tools for healthy aging in dogs, and we want to see that studied directly. For a broader look at food and lifespan, read Can Diet Help Your Dog Live Longer?.

Weight management: the best-studied way to lower inflammation

Keeping your dog lean is the most proven way to lower chronic inflammation in dogs. Body fat stores energy, and it also releases inflammatory signaling molecules called adipokines. More fat means more of these signals circulating in the body.

Two studies show that weight loss reverses part of this. In a 2009 study of 26 overweight dogs, CRP, haptoglobin (another inflammation protein), and TNF-α all fell after the dogs lost weight. In a 2011 study of 25 dogs, the dogs lost an average of 23% of their body weight over about 26 weeks. Their median CRP fell by more than 40%.

Staying lean also adds years. In the Labrador lifespan study, 48 Labrador retrievers were followed for their whole lives. Dogs fed 25% less than their littermates lived a median of 13 years, compared with 11.2 years. They also developed osteoarthritis and other chronic conditions later in life.

How to keep your dog at a healthy weight

• Check body condition as well as weight: Ask your vet to show you how to feel for your dog's ribs and waist, and recheck monthly.
• Measure every meal: Use the same measuring cup each time, and adjust portions as your dog ages and slows down.
• Use a calculator as a starting point: Our portion calculator estimates daily amounts for adult and senior dogs based on weight, age, activity, and treats. It is not designed for puppies under one year.
• Keep them moving: Regular walks and play help maintain muscle, which matters more as dogs age.

For senior-specific portions, see How Much to Feed a Senior Dog.

Stress, trauma, and other everyday factors

Chronic stress and early trauma raise inflammation in people, and the early dog research points in the same direction. In humans, the evidence is strong. The Dunedin study followed about 1,000 people in New Zealand from birth. Those who were maltreated as children were 1.8 times as likely to have high CRP at age 32, even after accounting for adult stress, health habits, and income.

What we know about stress in dogs

No large study has yet measured inflammation markers in dogs with long-term stress or a history of trauma. Studies of fear, training, and home life do link a dog's emotional world to physical health.

• Fear and lifespan: In a 2010 survey of 721 dog owners, dogs with extreme fear of strangers died about six months earlier. Separation anxiety and fear of things such as noises were linked to more frequent and more severe skin disease.
• Training methods: In a 2020 study of 92 dogs, dogs trained with punishment-based methods showed more stress behaviors and larger rises in cortisol, the main stress hormone. They also responded more pessimistically in a test given outside of training.
• Social support: In a Dog Aging Project study of more than 21,000 dogs, social companionship, such as living with other dogs, was linked to better health. Its effect was about five times larger than that of household financial hardship.

These studies show associations, and they relied partly on owner reports. They cannot prove that stress causes inflammation in dogs. The direction of the findings matches the human research.

Ways to lower your dog's stress

• Use reward-based training: Treats, praise, and play teach new behaviors without the stress responses linked to punishment.
• Keep routines predictable: Regular times for meals, walks, and sleep help many dogs feel settled.
• Give them company and enrichment: Time with people and other dogs, sniff walks, and puzzle feeders all support a calmer, more social life.
• Get help for fear and anxiety: A veterinary behaviorist can build a plan for noise fears, separation anxiety, or fear of strangers.

Many adopted dogs arrive with a hard past, and many settle in well with patience and a stable home. If your rescue dog shows lasting fear, a vet visit is a good first step, since pain and illness can look like anxiety.

Dental health

Gum disease is very common in adult dogs, and it is a steady, treatable source of inflammation. In a 2011 study of 38 dogs, more severe gum disease was linked to higher CRP. After professional dental treatment, CRP fell, and it fell most in dogs with the worst gum disease. Daily tooth brushing and regular dental checkups help keep this source of inflammation in check.

Related reading: How Long Do Dogs Live?, Blue Zones for Dogs, and our Q&A with Dr. Blake Hawley DVM on our Senior formula.

Frequently asked questions

What is inflammaging in dogs?

Inflammaging is the slow rise in chronic, low-grade inflammation that comes with age. A 10-year study of 80 dogs found that CRP, a key inflammation marker, rose about 30% as the dogs aged. A 2024 Dog Aging Project pilot study found higher levels of the inflammatory cytokines IL-6, IL-8, and TNF-α in older dogs.

What are the signs of chronic inflammation in dogs?

Chronic, low-grade inflammation usually has no visible signs, which is why it is hard to spot at home. Acute inflammation shows up as swelling, heat, redness, or pain. Conditions that keep inflammation going, such as arthritis, itchy skin disease, and gum disease, have their own signs, like stiffness, scratching, or bad breath. Your vet can check for inflammation with bloodwork such as a CRP test.

Can a blood test measure inflammation in my dog?

Yes. Vets can measure C-reactive protein (CRP), which rises within hours of infection, injury, or surgery, according to a 2022 review. It is used to support a diagnosis, track treatment, and watch recovery. CRP does not show where inflammation comes from, and researchers have not yet defined a range for age-related inflammation in healthy dogs.

What is the best anti-inflammatory diet for dogs?

No single diet has been proven to lower chronic inflammation in healthy dogs. A good starting point is a complete and balanced food fed in portions that keep your dog lean. The long-chain omega-3s EPA and DHA have the strongest evidence, and a 2022 meta-analysis supports them for arthritis in dogs. In people, eating patterns rich in fiber, legumes, whole grains, and omega-3s are linked to lower inflammation.

Does weight loss reduce inflammation in dogs?

Yes. In a 2011 study, 25 dogs lost an average of 23% of their body weight, and their median CRP fell by more than 40%. A 2009 study of 26 overweight dogs also found lower CRP, haptoglobin, and TNF-α after weight loss.

Can stress cause inflammation in dogs?

It may. In people, chronic stress and childhood maltreatment are linked to higher CRP, according to the Dunedin study. In dogs, the research is earlier. A 2010 survey of 721 owners linked extreme fear of strangers to shorter lives and anxiety to more severe skin disease.

References

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