Hello, welcome to JustAnswer! I am a licensed veterinarian, and I'll be happy to help you in any way I can.
Given that both dogs are coughing, there's a good likelihood that this is a viral or bacterial illness.
Since they are eating well, and not showing other problems, it is possible that their immune systems may clear the infection within 7-10 days, without the need for medication.
cough suppressants can be used on an as-needed basis, the usual recommendation is Robitussin-DM, dosed at 1mL per 10 pounds of body weight, every 8-12 hours,
but antibiotics may be needed if the problem persists for more than 10 days, or if at any time they stop eating, or become lethargic, or there's any yellow or green discharge from the eyes or nose.
those would all be justification for seeking veterinary care right away.,