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Coughing up blood is a sign of heartworm so if the dog has not been on a monthly heart worm preventative then this would be a concern. I am going to direct you to a site that will give other symptoms as well. It will also tell you what treatment is necessary. i would definitely get an appointment with the vet for diagnosis and so treatment can begin. http://www.petplace.com/dogs/heartworm-disease-in-dogs/page1.aspx
I do hope all works out well with your dog.