Riverwood Mono Protein Wet Food: Duck review

Every one of the eight tins lands in our Excellent band, and the gap between the strongest and the least of them is small. The wet shelf scores well generally, so the typical adult recipe wears that Excellent label as well. This range clears the mark on the strength of what it leaves out as much as what it puts in. Protein and processing reads Excellent on all eight, with nutritional balance and transparency reading Outstanding on every tin in the range.

Ingredients, as declared: 70% duck, 28.5% broth, 1% minerals, 0.5% sunflower oil.

Four lines and the recipe is finished: 70% of the named animal, 28.5% broth or stock, 1% minerals and 0.5% sunflower oil. The lamb tin trims its mineral line to 0.1% and lifts the meat a fraction in its place.

Several of the labels open the animal up for you. The horse tin lists meat, heart, liver and lung. The lamb adds tripe. The turkey names heart, meat, liver, stomach and neck. The veal is heart, lung and tripe. Organ meat is where much of the vitamin content of a meat-only recipe lives, and printing which parts went in is more detail than most wet labels offer.

The only added fat is sunflower oil, at 0.5%. It is pressed from seed, low in saturated fat and carries some vitamin E of its own, which suits a recipe that has nothing else to lean on.

The carbohydrate line on these tins deserves a word. There is no starch ingredient anywhere in the range, yet the estimate reads as high as 23.3% of dry matter on the veal. The figure comes from subtracting everything else from the total, not from measuring starch. On a lean, meat-only label it mostly reflects rounding in the printed analysis, and there is nothing in the tin you could point at.

The added panel is short and dosed per kilo: vitamin D3 at 200 IU, zinc at 25 mg, manganese at 1.4 mg and iodine at 0.75 mg on most labels. Copper at 1 mg appears on several, and vitamin A joins on the duck and venison. The duck tin is also the only one to put a figure on calcium, at 1.3% of dry matter, a comfortable level for an adult dog.

Duck at 70% with broth at 28.5%. The lightest tin for energy at 91.7 kcal per 100g, and the highest in protein at 52.5% of dry matter once the water is out. No other label in the range prints a calcium figure.

Prices run from £9.48 to £12.52 a kilo depending on the animal, in 400 g tins sold as a pack of 6.

For a 15kg adult dog in moderate condition that comes to between £6.80 and £10.96 a day, or roughly 654 to 916 grams. The sums behind that assume about 840 kcal a day (110 × bodyweight^0.75, the standard maintenance estimate). The veal tin gives the lowest day rate of the eight despite not being the lowest per kilo, because it carries the most calories per 100 g and so takes the smallest portion.