Fostering a senior, breathing heavy?

Today we picked up a senior foster from a very small shelter in north Georgia. This shelter does not vet the animals at all, only gives a voucher once they are adopted. They have estimated her age to be about 8. The vet is not open until Monday. Although she is playing, eating and drinking, her breathing I somewhat labored and she pants heavily at times before relaxing. Could this be due to the stress of a new place? I know there is a good possibility of heart worms (not tested yet), anyone have any advice??
Thanks so much.

[Cliff Redford, DVM]

Sorry to take extra time getting back to you. First off great job rescuing a dog, you should be commended. It sounds derious enough to have a full physical exam done and perhaps some blood tests and radiographs. Heartworm disease is a possibility and a simple test will determine if that is the case. Overall cardiovascular health may need to be assessed depending upon your dog's exam findings, heart sounds etc. I would be recommending a simple CBC (complete blood count) to look or infections or anemia, and a profile to assess overall organ function. These tests will give the vet a good starting point to help your new family pet get the best care possible.