Leave Adelaide early and head south along the coastal A13, stopping first at Aldinga Beach for a brisk on-lead walk and sunrise views, then continue to Sellicks Beach for a coffee at a pet-welcome café before stretching legs on the dunes. Mid-morning, detour through McLaren Vale for a scenic drive past vineyards (many cellar doors have outdoor seating where well-behaved dogs are allowed) and a quick picnic at Wirra Wirra Winery grounds or a nearby dog-friendly reserve before continuing toward the Limestone Coast.
In the afternoon, take the scenic coastal drive to Goolwa and stretch legs on the dog-friendly stretch of Hindmarsh Island with estuary views and birdwatching; nearby grab a late-lunch takeaway from a pet-welcome cafe on the Murray mouth foreshore. Continue toward the Limestone Coast with a photo stop at the dramatic cliffs of Cape Jaffa, then arrive in Mount Gambier in time for a peaceful evening walk around the sinkholes at Centenary Tower Reserve, before checking into a pet-friendly stay such as The Barn Bed & Breakfast or a local pet-welcoming motel.
After checking into your pet-friendly accommodation, take a relaxed sunset stroll along Blue Lake Reserve Coastal Walk, letting your dog sniff the shoreline and watch the water change colour, then head to the lively foreshore at Port MacDonnell Jetty for fresh seafood from a takeaway stall and coastal views. Finish the night with a cosy drink on the outdoor deck at The Anchorage Motel & Bistro (pet-welcome on the verandah) where you can plan tomorrow's early leg toward the Victorian border while your dog dozes at your feet.
Head out early from Mount Gambier and follow the Princes Highway east, stopping first at Robe for a seaside stretch-walk your dog along Long Beach and grab takeaway coffee at a pet-friendly café on the main street. Continue into Victoria with a scenic pitstop at Port Fairy where you can stroll the historic streets and let your pet sniff around the foreshore at Griffiths Island, then refuel and enjoy a relaxed brunch at an outdoor-friendly eatery before the longer highway leg toward the New South Wales border.
After a morning departure, head east and stop for a dog-friendly beach walk at Portsea Back Beach where coastal cliffs and wide sands offer a refreshing stretch before the highway leg; nearby, enjoy takeaway fish and chips from Sorrento Fish & Chips to eat on the foreshore while your pet rests in the shade. Continue through Gippsland with a scenic break at Lake Tyers Beach, letting your dog explore the dunes and you enjoy estuary views, then refuel at a pet-welcome cafe in Bairnsdale before pushing on toward the Victorian/New South Wales border as daylight begins to wane.
After the long highway leg, arrive in the Canberra region and unwind with a gentle riverside walk along Lake Burley Griffin's Yarralumla Shores, where your dog can roam on-lead while you enjoy sunset reflections and views of the Parliamentary Triangle. For dinner, choose a pet-welcoming spot like The Dock at Kingston Foreshore for outdoor dining and fresh local fare, then settle into a pet-friendly stay such as Ovolo Nishi (pet policy permitting) or a nearby pet-welcoming apartment to relax and plan tomorrow's easy city exploration.