Hello and thank you. I have a 12-year-old Pitbull mix named flower who had heartworm and she was treated with the three shot series back in June of 2025 and then 3 weeks ago she had a mammary gland tumor removed. Three days after surgery she started honking heaving and coughing. I’m afraid her heartworm has come back. She still eats and drinks and gets up but doesn’t look comfortable All she does is walk around and cough, spit up . I don’t have the strength to put her down but I’ve also spent thousands and I’m at a loss of what to do. Any advice would be helpful Thank you