Sentence 1: After coming in from outside one of my dogs was very sick. 
 Sentence 3: I tried waiting a few days to take him to the vet to see how he was 
 Sentence 4:  He started coughing more and more so I took him to the vet 
 Sentence 5:  The vet diagnosed him and gave him some medication as well 
 Given Sentence 2: He was constantly coughing and I felt really bad.