Mechanism of Action
DHA and EPA integrate into cell membrane phospholipids throughout the body, influencing membrane fluidity and receptor function. They are metabolised into eicosanoids including resolvins and protectins, which have direct anti-inflammatory effects and promote resolution of inflammation. In the skin, they support the integrity of the lipid barrier, reducing transepidermal water loss and the inflammatory response to allergens. In the brain, DHA is the dominant structural fatty acid in neuronal membranes and synaptic membranes and is essential for signal transduction and cognitive function. In the eye, DHA is concentrated in the retinal photoreceptors and is required for normal phototransduction. In joints, EPA reduces the production of prostaglandin E2 and leukotriene B4, inflammatory mediators that contribute to cartilage degradation.
Evidence Summary
Omega-3 fatty acids have one of the strongest evidence bases of any supplement category in veterinary medicine. In skin health, multiple randomised controlled trials in dogs with atopic dermatitis show significant reduction in pruritus scores with EPA and DHA supplementation. A systematic review by Mueller et al (2004, Veterinary Dermatology) found evidence supporting omega-3 supplementation as an adjunctive treatment for canine atopic dermatitis. In brain health, dietary DHA is essential for normal neurological development in puppies and kittens and for maintaining cognitive function in older animals. In joint health, EPA has evidence for reducing inflammatory mediators in synovial fluid. The key variable across all applications is achieving a therapeutic dose, as most commercial pet foods provide insufficient omega-3 to produce clinical benefit.
In Petz Park Products
Skin and Coat for Dogs: DHA 210mg, EPA 38mg per scoop. Skin and Coat for Cats: DHA 52.5mg, EPA 9.5mg per scoop. Brain Support for Dogs: EPA + DHA 72mg per scoop. Eye Support for Dogs: EPA + DHA 100mg per scoop. Eye Support for Cats: EPA + DHA 23mg per scoop. Multivitamin for Dogs: EPA/DHA 30mg per scoop. Multivitamin for Cats: EPA + DHA 15mg per scoop.
Safety and Considerations
DHA and EPA are safe for dogs and cats at supplemental doses. At very high doses they may have mild anticoagulant effects and should be used with caution in animals on anticoagulant medications or scheduled for surgery. The doses in Petz Park products are supplemental rather than pharmacological and the risk is low. Source matters: marine-sourced omega-3 provides the active DHA and EPA directly, while plant-sourced omega-3 (such as linseed oil) provides ALA which requires enzymatic conversion that is inefficient in dogs and very limited in cats.