English Mastiff owners?

this is normal for age because metabolism slows down and probably some weight loss too (less insulation on body)... needs to have pillow or padding to insulate from floor even if floor is carpet the dog will stay warmer with pillow or blanket to lay on... i found that a perfect dog bed pillow for big dogs like this is the cushion from papasan chairs... usually you can get better stuff for them if you forget about "dog" items & instead look for human items such as clothes, blankets, coat etc... other than that you might try farm supply store & look at horse blankets & livestock stuff