Kennel cough, Bortatella a sniffle by any name.... sigh sure sounds as if your baby has the dog crud. Even if she was vaccinated ( nasal or injected) keep in ind the vaccine only covers some of the 27 or so varieties of the crud. Let your vet know asap, post surgical dogs do not need this type of complication...

Antibiotics only work against bacterial infections, but the vet may use them as a preventative. Benadryl is an antihistamine, but it would help to make her drowsy. I don't know about using Robitussin. You really don't want to suppress productive coughing. If she sleeps in a steam tent tonight...

My 7yo lab Chanel had Kennel cough as a puppy, it was so severe when we got her that curing it proved almost impossible. Until she was about 6 months she had repeated Kennel Cough like 'attacks' for a while which left her with permanent lung damage. Her lungs didn't grow along with her body...