Dog snoring when awake, runny nose and pants easier?

My dog is around 9 and recently she seems to be making snoring sounds when awake. She isn't coughing more or majorly different. She has seemed to be panting more than usual after walks and very often has a runny nose. She also seems tired more frequently.Mind you as a older dog this is hardly unusual and we've recently got a younger dog which may be causing her to be worn out quicker. Do you think its a cold, respiratory infection, some other problem. Will go to vets if she gets worse but curious about what it could be. It seems to have occured over the past few months but we got our other dog at around that time too. On a different note, shes also got a small pus filled spot on her elbow, and some fur is missing around it. But quite small. It is on the leg she has been limping on recently so wanting to make sure they are unrelated. Sorry for the random enquiries, just shes getting on a bit and shes precious to us.