
Also you need to bear in midn that a puppy or adult of this breed do not actually need a lot to eat. I would hazard a guess that he will not need any more than about 4oz a day, so over 4 meals that really is only a tiny amount.
How does he look and feel. You should easily be ble to fel his structure, ribs etc under a light covbering of flesh and fur. You shouldn't have to dig for them and the bones should not protrude.
If he is healthy then just accpt that he will misss some meals and offer him a normal amount next meal time. do not be tempted to get him to eat the missed amount. a little hunger will encourage him to eat what is put in front of him.
I had a bitch who I called anorexic, but she was alwys just a bit leaner than I wanted, though fit and healthy as can be. Seh is now 7 and I am finally having to watch her weight (though spaying ehr last year may have contributed).
Beleive me the vast majoruity of pet Cavaliers are overweight, some extremely so, so being naturally lean will likely keeo him healthy.