Supplements

A complete-and-balanced food already meets nutritional requirements - supplements are for specific situations, not insurance. Always tell your vet what you're giving; interactions are real.

Supplements aren't regulated like drugs. Look for the NASC quality seal, brands that publish third-party testing, and skip anything promising to cure things.

Omega 3 fish oil: The best-evidenced supplement in dogs - EPA/DHA support skin, coat, joints, and there's evidence for kidney and cognitive benefit. Dose matters and it's easy to overdo; ask your vet for an amount, and store it cold (rancid oil is worse than none).

Joint support: Glucosamine/chondroitin/green-lipped mussel are widely used with mixed evidence; omega-3s and - far more importantly - keeping the dog LEAN do more for joints than any capsule. Prescription options exist when it matters.

Probiotics: Vet-specific strains (not human yogurt) can help with diet transitions, stress colitis, and post-antibiotic recovery. Effects are strain-specific, so the brand matters.

Others: Milk thistle, SAMe, MCT oil, and CBD all get mentioned in dog circles - each has a real use case and a lot of hype. CBD in particular is under-regulated and interacts with some medications; vet conversation first, always.