Meter the scene as already mentioned using matrix, rather than the dog using spot metering. Then adjust your eV over or under accordingly (for example +0.5 stop to compensate for the bright light and bring the dog out more clearly, although I usually like to underexpose a third stop in my photos because Japanese love bright colors so their meters tend to overexpose just a bit). Those good photos you got were probably because the dog wasn't in the center of the frame where the camera was metering. If it sees a dark object it will overexpose, light object it will underexpose.