Dog coughing attack?

[WaterGirl32]

My chihuahua was just in the vet the end of December for her annual shots and a check up.  Her heartworm was negative at this time as well.

She is a house dog, she uses a litter box and never goes outside when it is cold.

She is playful usually.  Lately, she has been having attacks where she is gasping for air and wheezing with a panicked look on her face.  She then coughs up some foamy spit.  I can usually help stop this by calming her down.  This happens when she gets excited or hot.  (after she has been under her blanket for a while.)  Her last check up was positive, they found nothing wrong with her.  She has definitely been more detached than normal, she sleeps alot (although she usually sleeps quite a bit).  

During her attacks, she never experiences blue gums or lips.

Her last owner was a HEAVY smoker.  I don't know if that has relavance.

She is fed on Innova and Canidae products.

I scheduled a vet visit for her tomorrow, but I am so worried about her.  I am hoping someone may be able to give me some advice or an opinion of what may be affecting her.

[WaterGirl32]

So I took her to the vet yesterday.  She is fine!  Just some allergens.  Thanks!

[Jaybay]

Something certainly isn't right, so why not take her to your vet?  Dogs pick up viruses and bacterial infections just like we humans do, so it's entirely possible that she caught something since her last visit.

[WaterGirl32]

I probably should add that she was boarded at the vet for two nights on December 29 and 30th.  (our furnace was out so her and my other dog stayed at the vet)