i have a 3 month old cat who weight about 2 and a half pounds so unless the cat is way underweight they will be more than a pound. in fact if they weight under 1.5lbs they are underweight
how much does your kitten weigh? was this prescription not given by a Vet? I am not sure you should be giving a young kitten such a strong antibiotic...yes it is 5mg per lb....but does the kitten even weight a full pound? I doubt it at 12 weeks old.
this is a systemic penicillin and has potential to produce serious even fatal allergic reactions...please consult a Vet before giving any medications to a cat esp a kitten..
I looked it up and it says 5 to 10 milligrams per pound 12 to 24 hours so I'm guessing it's 5 mg per pound every 12 hours or 10 mg per pound every 24 hours. But either way it goes by weight not age.