Faecal moisture content can determine whether faeces appear soft or firm, and faecal character can influence whether owners are satisfied with a dog food. In a previous study, dogs appeared to produce softer faeces after noon. The purpose of the present study was to determine whether time of defecation affected canine faecal water content. A total of eight hound dogs were fed one of four canned diets as a single meal each morning for 1 week per diet in a Latin square design. All four diets contained approximately 77 % moisture and, on a DM basis, 24 MJ/kg gross energy, 23 % crude protein, 32 % crude fat, 31 % N-free extract and 1 % crude fibre. The proportion of dietary protein from soya-derived texturised vegetable protein (TVP):beef was 0:100, 14:86, 29:71 and 57:43, respectively. Soya carbohydrate partially replaced maize starch as TVP increased. Faeces were collected by direct catch during the sixth morning and afternoon of each diet period. Mean faecal moisture content was greater in the afternoon than in the morning (79 v. 71 %; P = 0·01) and increased with dietary TVP (P ≤ 0·0001), and there was an interaction between time of day and percentage TVP (P = 0·003). Faecal moisture content differed from morning to afternoon only with TVP in the diet. Faecal wet weight was similar from morning to afternoon. This suggests that time of day and presence of TVP from soya should be taken into account when evaluating the effect of a diet on faecal form and moisture content in dogs fed once daily.