All reputable pet food manufacturers include a feeding guide with their foods. One must remember that these guidelines provide a starting point only and that you will know within a relatively short period of time( 1 to 2 weeks ) if your animal is being over or under fed simply by observing his body. He should of course not appear gaunt but his ribs should be easily felt with your fingers. Unfortunately, far too many of the animals we see are overweight which predisposes them to a number of health problems.