My friend's shepherd mix, Otto, started pausing at the bottom of the stairs around age nine. Not every time. Just often enough that she noticed. He'd stand there, look up, then take the first step like he was testing ice.
She assumed it was just age. It wasn't. It was pain. And that distinction matters more than most people realize.
The science
Osteoarthritis is the most common chronic condition in aging dogs. Studies estimate it affects up to 20% of dogs over one year old — and the numbers climb sharply past age seven. The tricky part is that dogs hide pain well. By the time you notice the hesitation at the stairs or the slower pace on walks, the joint damage has usually been building for a while.
The good news is that the research on treatment has gotten pretty solid in recent years.
Fish oil is the supplement with the strongest evidence behind it. A randomized, double-blind, placebo-controlled trial published in Prostaglandins, Leukotrienes and Essential Fatty Acids (Mehler et al., 2016) enrolled 74 dogs with confirmed osteoarthritis and dosed them with fish oil at 69 mg of EPA+DHA per kilogram of body weight daily for 84 days. All clinical outcomes measuring discomfort, lameness, and joint severity improved significantly compared with placebo. Worth noting: the study was partially funded by Veterinarian Recommended Solutions, a company with a fish oil product, and one of the lead authors disclosed compensation from them. The results are still compelling, but the funding matters.
A separate JAVMA study — randomized, double-blinded, 38 dogs at two university clinics — used force-plate gait analysis to measure actual weight bearing. Improvement in peak vertical force was evident in 82% of the dogs in the fish oil group, compared to essentially no change in the control group.
NSAIDs are still the most effective pharmaceutical intervention. Meloxicam, carprofen, and grapiprant (Galliprant) all have solid clinical backing. Grapiprant is particularly valuable for dogs with contraindications to traditional NSAIDs, like those with kidney or gastrointestinal disease, since it works through a different mechanism. PubMed Central Long-term use of any NSAID requires periodic bloodwork — liver and kidney function checks — but they work.
Glucosamine and chondroitin. Here's the honest answer: the evidence is thin. The efficacy of these supplements is controversial, and the research is limited and often industry-funded. ResearchGate That doesn't mean they're useless, but it does mean the confidence you'd want before spending $40 a month on them isn't really there. Worth a conversation with your vet if your dog is already on them, but I wouldn't start here.
Physical therapy is underused and underestimated. In addition to pain management with drugs, exercise modification and physical therapy are important for alleviating pain and improving mobility in dogs with osteoarthritis. DVM360 Underwater treadmill therapy in particular has real evidence behind it — it builds muscle around compromised joints without the impact load. Not cheap, but for a dog with significant mobility loss, it often does more than any supplement.
What it means for your dog
The stair hesitation, the slower pace, the reluctance to jump into the car — none of that is just "getting old." Those are signs of pain, and pain is treatable.
Document what you're seeing: which leg, how often, what triggers it. Bring that to your vet and ask about a formal mobility assessment. Ask specifically about fish oil dosing if you want to start there, and ask about NSAIDs if the signs are more than mild.
Don't wait for a limp. By the time dogs are visibly limping, they've been compensating for a while.
The bottom line
Joint pain in senior dogs is common, often missed, and genuinely treatable — fish oil has real evidence behind it, NSAIDs work, and physical therapy is worth considering for dogs with significant mobility loss.
One recommendation: Ask your vet about Galliprant (grapiprant) if your dog is over seven and showing any stiffness. It's FDA-approved for canine osteoarthritis pain and designed with long-term use in mind — particularly for dogs who can't tolerate traditional NSAIDs.