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Oily fish deliver joint-supporting Oméga-3 for dogs—but quality is inconsistent. Overfishing, contaminants, and falling EPA/DHA levels: see safer options.
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Natural IngredientsOsteoarthritis is a scourge for our dogs' mobility. Oméga-3, particularly EPA and DHA, are the most recognized nutritional solution for supporting joint function and combating inflammation.
These fatty acids are naturally present in fatty fish (sardine, salmon, anchovy).
However, these sources face major concerns: declining nutritional content, the risk of contaminant bioaccumulation, and ecological pressure.
At Sensilia Laboratory, our commitment is to guarantee maximum efficacy and absolute purity of the Oméga-3 you give your pet, with the least impact on the environment.
This article reveals the current challenges linked to fish sources, drawing on scientific studies, to help you choose an Oméga-3 supplement that is truly safe and effective.
For decades, fatty fish have held a central place whenever it came to providing Oméga-3 beneficial to health. A simple reason explains this position: they are one of the few dietary sources naturally rich in EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the two marine fatty acids considered most beneficial for the body.
Contrary to what one might imagine, fish do not synthesize these Oméga-3 themselves. They accumulate them by feeding on marine microalgae, plankton, or organisms that consume them. This origin gives them a particularly interesting lipid profile: Oméga-3 that are directly assimilable, in proportions difficult to find in terrestrial foods.
Historically, several factors reinforced this status as a "reference":
Before the rise of alternative sources (microalgae in particular), fatty fish therefore represented the simplest, most direct, and most natural way to obtain the Oméga-3 essential to the body.
Not all species are equal when it comes to providing marine Oméga-3.
So-called "fatty" fish have higher EPA and DHA levels for a simple reason: they store more lipids in their tissues, and these lipids come mainly from their diet of microalgae, zooplankton, and small crustaceans naturally rich in Oméga-3.
Unlike lean fish (such as cod or sole), which mainly use their muscle reserves for energy, fatty fish accumulate fat in their tissues, skin, and abdominal cavity. This fat serves as an energy reserve for long migrations, cold waters, or periods when food is less abundant.
Among these fatty fish, there is a wide variety of species:
| Species | EPA (g) | DHA (g) | EPA + DHA (g) |
|---|---|---|---|
| Mackerel | 0,9 - 1,0 | 1,0 - 1,6 | 1,9 - 2,5 |
| Herring | 0,7 - 1,0 | 0,7 - 0,9 | 1,6 - 1,7 |
| Salmon | 0,4 - 0,8 | 0,6 - 1,2 | 1,0 - 1,8 |
| Anchovies / Sardines | 0,4 - 0,5 | 0,6 - 0 | 1,0 - 1,4 |
| Trout | 0,4 - 1,2 | 0,4 - 1,8 | 0,5 - 3,0 |
| Tuna | 0,3 - 0,4 | 1,0 - 1,2 | 1,3 - 1,6 |
The numerous studies conducted on fish oils rich in EPA and DHA show a consistent set of results: modulation of inflammation, a moderate but real improvement in joint comfort, and several beneficial effects on metabolic and cardiovascular profiles.
Several controlled trials have evaluated EPA/DHA-enriched foods in arthritic dogs:
Ces travaux montrent des progressive benefits, generally visible after 6 to 12 weeks of supplementation.
At the cellular level, Curtis et al. demonstrated that EPA/DHA reduce the [REDACTED] of inflammatory mediators (PGE2, NO, MMP) in arthritic canine chondrocytes, confirming a direct mechanism of action on joint tissues.
Studies also show positive systemic effects:
These results suggest a decrease in low-grade inflammation and better cellular protection.
While fish oil has long been considered the most accessible source of EPA and DHA, several major drawbacks are now well documented. They concern nutritional quality as much as sustainability and safety.
Small fatty fish such as anchovy, sardine, herring, and mackerel are at the heart of the global [REDACTED] of fish oil and fish meal. They also form the base of the marine food chain.
Bach et al. show that the [REDACTED] of fish oils increasingly relies on stocks that are fully exploited or overexploited, and that "ecosystem scarcity" increases with the intensification of fishing targeting these forage fish.
This study highlights two major risks:
For their part, FAO reports (2020–2022) show that more than one third of global stocks are overexploited, compared to only 10% in the 1970s, confirming a structural trend.
Because they are naturally rich in lipids, fatty fish also tend to accumulate more environmental contaminants. Several recent studies show that this accumulation concerns heavy metals, persistent organic pollutants, and microplastics alike.
The study by Nøstbakken et al. shows that fatty fish, particularly salmon, mackerel, and herring, can contain measurable levels of dioxins and dioxin-like PCBs, compounds that accumulate in adipose tissue over time. Even though observed concentrations generally remain within regulatory limits, they are systematically higher in fatty species than in lean fish, confirming accumulation directly linked to lipid content.
An analysis of the Italian market conducted by Nevigato et al. revealed that certain fish oil supplements show variable levels of oxidation and contaminants, suggesting that quality is not uniform among products available on the market and that purification does not always completely eliminate all undesirable traces.
These data complement the opinions of the European authority (EFSA), which reminds us that fish is the primary dietary source of methylmercury and that lipophilic contaminants persist durably in marine ecosystems.
Overall, studies show that despite their nutritional interest, fatty fish today face a combination of contaminants whose level depends on species, age, and catch area. This is an important parameter when evaluating different Oméga-3 sources.
Several recent studies highlight a concerning trend: the decrease in the natural EPA and DHA content of wild fish, particularly in regions where fishing pressure is strongest.
When stocks of small pelagic fish are overexploited, they no longer have time to recover or rebuild their Oméga-3 reserves. This phenomenon is accentuated by a second factor: the reduction in primary [REDACTED] of Oméga-3 by microalgae, a direct consequence of water warming.
Between 2000 and 2023, in the Mediterranean Sea, annual EPA + DHA catches fell from approximately 15 tonnes to 6 tonnes, a drop of nearly 60%.
Farmed fish are not spared. They are traditionally fed with fish meal and fish oil, themselves derived from wild stocks, which perpetuates fishing pressure.
To reduce this dependence, some aquaculture farms now substitute these ingredients with soy or other plant sources devoid of EPA and DHA, which mechanically dilutes the Oméga-3 concentration in farmed fish.
Result: in some farms, salmon EPA + DHA levels have decreased by approximately 50% over roughly a decade (Sprague et al.).
In the face of growing limitations linked to fatty fish and the oils derived from them, several Oméga-3 sources are emerging today as safer, more stable, and significantly more sustainable options. Two of them stand out particularly: microalgae oil and green lipped mussel oil.
Marine microalgae are the organisms that naturally produce EPA and DHA. Fish are merely their "accumulators." By going directly to the source, microalgae oil offers several major advantages:
It is today the preferred source of EPA/DHA for many laboratories committed to animal and human health.
Discover our article on the benefits of algae oil
The New Zealand green-lipped mussel (Perna canaliculus) has the particularity of containing:
It is also a better regulated supply chain, based on harvests strictly controlled by the New Zealand government, which limits pressure on wild stocks.
Discover our article: Green-lipped mussel, remedy for osteoarthritis
Because they simultaneously address the three challenges posed by fish oil:
They make it possible to offer the animal Oméga-3 that are truly effective, while avoiding the pitfalls linked to variability, oxidation, and the uncertain sustainability of fatty fish.
Fatty fish have long been the reference for providing EPA and DHA, two Oméga-3 essential to joint support. Studies show they can genuinely improve mobility, reduce inflammation in arthritic dogs when provided in sufficient quantity.
But current knowledge also reveals their limitations: significant variability in Oméga-3 content, contaminant accumulation, gradual decline in EPA/DHA levels linked to overfishing and climate change. These factors make fish oil less reliable and less sustainable today.
That is why more stable and cleaner alternatives are emerging, such as microalgae oil and green lipped mussel oil, capable of offering highly bioavailable Oméga-3, free of marine contaminants and from sustainable supply chains.
At Sensilia Laboratory, this evolution guides our work: offering Oméga-3 sources that are as effective as they are responsible. PERNIXOL®, formulated from green lipped mussel oil extracted by supercritical CO₂ and microalgae oil, fits within this approach by offering a high-performing, pure EPA+DHA intake that respects the oceans.
A way to support the dog's mobility with Oméga-3 truly suited to today's scientific and ecological challenges.
Discover PERNIXOL®
This article was written by the R&D team at Sensilia Laboratory, experts in animal nutrition.