The bed and the floor do most of the work
For an arthritic dog, comfort is largely decided by what he lies on and what he walks on. Give him a thick, supportive mattress at floor level in the warmest draft-free corner he actually likes — cold and damp settle into sore joints, and a bed he must climb into will quietly go unused. If he shares sofas or your bed, add a ramp or wide steps now, before a bad landing teaches him fear. Then walk his daily routes as he experiences them: bed to bowl, bowl to door, door to garden. Every polished, tiled, or laminate stretch on those routes gets a rug, runner, or mat, because one splayed slip can set an arthritic dog back for days and make him afraid to move at all.
Weight, nails, and the load on sore joints
Nothing you do at home helps arthritic joints more than keeping the dog lean. You should be able to feel ribs easily under a thin cover and see a waist from above; if you cannot, measured meals and an honest cut in extras will do more than any cushion. Ask your veterinarian what weight to aim for and weigh monthly to prove the trend is right. Keep nails short and the hair between pads trimmed, because long nails force arthritic toes and wrists into painful angles and pads that skate undo all your rug work. Place food and water where he can eat standing naturally on a non-slip mat, without stretching down a step or up onto a platform.
Movement: little, often, and never the weekend-warrior pattern
Arthritic dogs stiffen with rest and flare with overuse, so the home rhythm should be gentle and frequent: short, steady walks several times a day on forgiving ground, a slow start while joints warm, and no sudden hour-long adventures because the weather improved. At home, encourage regular position changes — a potter to the garden, a sniff round the fence — rather than twelve unmoving hours followed by stairs. Keep floors and garden access step-free where you can, help him in and out of the car with a ramp rather than lifting a heavy, wriggling dog badly, and dry and warm him after wet walks, because chilled muscles guard sore joints and tighten everything.
Partner with your vet and track the pattern
Home comfort measures work best alongside veterinary care, not instead of it. Book a review if he starts struggling to rise, lags or refuses walks he managed last month, licks or chews at one joint, snaps when a hip is handled, or has more bad days than good in a fortnight — and seek prompt help for a leg he will not use at all, crying out, or sudden inability to stand. Note good days and bad days, what he did the day before each, and his weight, because that diary turns a vague worry into a plan the vet can act on. Storing those review dates, screening results, and your own comfort diary in KinsLe in his Pet Passport keeps the whole arthritis picture in one portable place.