cold

Dear Teachers

1, I wonder if there is any difference beteween (1) and (2).

(1), I have a cold.
(2), I have had a cold.

2, which is natural?

(1), Please excuse Mary from gym class today. She has a cold.
(2), Please excuse Mary from gym class today. She has had a cold.

Thank you in advance.

1- You still have a cold
2- You have recovered

With Mary, I see no real reason to excuse her if she has had a cold, unless she is still a bit weak, so the first sounds better.
;-)