What can cause fluid in the lungs?

Hi, My dog is a minature poodle he is approximately 8 years old. He is coughing quite a bit, it seems to be mainly of a night. Its sounds fairly gruff and dry, I'm wondering if its kennel cough, if so what should I do?

My Westie has been coughing a lot. We took her to a veterinarian and he took an x-ray which showed she has an enlarged heart and some mucus in her lungs. He gave her antibiotics which seem to be helping the cough its not as hacking as it was. Then he gave her theophylline but this made her too hyper and she was panting and coughing more. Any suggestions as what to do next? Appropriate tests or medicines to further diagnose the problem?

I was informed my 11-year-old dog has congestive heart failure problems...How can I help him with his coughing?

I recently brought my 3 1/2 year old Lhasa Apso to a new vet - who said he had a heart murmur. No one had ever told this to me before. How serious is this? What complications can arise? Can it be treated and how? Should I bring him to a cardiologist?

What is Subaortic Stenosis or SAS in dogs?