The Rat River in Manitoba is a meandering lowland river that flows through the southeastern part of the province, draining through communities including Carrick, Zhoda, Rosa, St. Malo, La Rochelle, St. Pierre Sud, St-Pierre-Jolys, and Otterburne before joining the Red River. The full canoe route runs from a starting point approximately 13 kilometres from Carrick to the Red River junction, passing the Sand River confluence and the Marsh River confluence along the way. A historical canoe map titled "Rivière aux Rats Canoe Route," produced by the Manitoba Department of Natural Resources Parks Branch, is available for purchase and is recommended for use alongside topographic maps when navigating the river.

The character of the river changes along its length. The upper and middle reaches, east of St. Malo, tend to be less silty, while the lower section winds slowly through a corridor of oak, ash, and aspen with a backdrop of Red River valley farmland, flowing between muddy banks. The river is generally slow-moving and suitable for canoes and kayaks, though paddlers should be prepared for log jams, which can be significant obstacles. At least one fast-flowing culvert has been noted in the lower reaches near the endpoint, presenting a challenge for less experienced paddlers. Dragging canoes over log jams may be necessary in some sections.

Water levels on the Rat River are an important planning consideration. The river near its confluence with the Red River may only be navigable when the Red River is running high and water is backed up into the Rat. During flood conditions or after heavy rainfall, the current can become unpredictable and the river unsafe for paddling; local fire departments have issued warnings during such periods. Overhanging trees that are normally passable at typical water levels may become impassable when the river is elevated.

The river passes through or near St. Malo Provincial Park, and the section from the Red River to near the bridge at Waverley Street is closed to motorized boats, making for a quiet paddling environment. The surrounding landscape supports wildlife including eagles, deer, and foxes. The Rat River Heritage Marsh, located near Rosa off Highway 59, is a notable natural feature along the route and is known locally for its bird and wildlife habitat.

The route is rated intermediate by at least one organized paddling group, and it has been used for guided canoe outings by Nature Manitoba and Paddle Manitoba.