What are eicosanoids and what do they do?

Where Do Eicosanoids Come From?

Eicosanoids are made from specific types of polyunsaturated fats found in cell membranes. Two of the most important sources are arachidonic acid (AA), which is an omega-6 fatty acid, and eicosapentaenoic acid (EPA), which is an omega-3 fatty acid. When the body is triggered by injury, infection, or stress, it releases these fats from the cell membrane and converts them into eicosanoids using specialized enzymes.

The type of fatty acid available—whether it’s omega-6 or omega-3—plays a major role in determining the kind of eicosanoid that gets produced. Eicosanoids derived from omega-6 fats like AA tend to promote stronger and longer-lasting inflammatory responses. This can be helpful for activating the immune system, but if left unchecked, it may also contribute to chronic inflammation.

In contrast, when the body uses omega-3 fats like EPA to make eicosanoids, the resulting signals tend to be less intense and more oriented toward resolving inflammation rather than sustaining it. These gentler signals help quiet the immune response and return tissues to balance after the initial threat has passed.

Because both omega-6 and omega-3 fats compete for the same metabolic pathways, the balance of these fats in the diet has a direct impact on how the body regulates inflammation. A diet skewed heavily toward omega-6 fats may tip the body toward a more pro-inflammatory state, while the inclusion of sufficient omega-3s can help moderate that response.

What Do Eicosanoids Regulate?

Eicosanoids influence a wide range of physiological processes:

• Inflammation: turning it on or helping resolve it
• Blood flow and clotting
• Fever and pain signaling
• Immune cell activity
• Tissue regeneration and wound healing

Their effects are highly localized and immediate. Eicosanoids don’t travel far in the body—they act where they’re made, and then break down quickly. This makes them powerful tools for fine-tuned immune control, especially in organs like the skin, gut, joints, and lungs.

Why Do Eicosanoids Matter for Dogs?

In dogs, just like in humans, eicosanoids help coordinate the immune response. When balanced correctly, they help the body fight off threats and repair damage efficiently. But when inflammation is overactive or poorly regulated—something common in modern dogs—eicosanoids can contribute to chronic discomfort, swelling, or immune hypersensitivity.

Because dogs consume diets that are often high in omega-6 fatty acids (from seed oils and grain-fed meats) and low in omega-3s (like EPA), their bodies tend to produce more pro-inflammatory eicosanoids. This imbalance may underlie issues like:

• Joint stiffness or arthritis
• Allergies or itchy skin
• Gut inflammation
• Chronic low-grade inflammation

Supporting the body with a better balance of omega-3s—particularly marine-sourced EPA—can help shift the body toward producing less inflammatory eicosanoids, which contributes to a more regulated immune environment.

Eicosanoids vs. Hormones: What’s the Difference?

While eicosanoids are often described as hormone-like, they differ from hormones in important ways:

Key Takeaways about Eicosanoids for Dogs

• Eicosanoids are fast-acting signaling molecules made from fats, especially omega-6 and omega-3 fatty acids.
• They help regulate inflammation, immunity, pain, and healing—critical functions in the body.
• The type of fat a dog consumes affects the balance of pro- vs. anti-inflammatory eicosanoids produced.
• A diet high in EPA (from marine oils) helps promote a healthier, more balanced inflammatory response in dogs.