The clinical symptoms and pathological characteristics of Phu Quoc dogs infected with Canine Distemper Virus (CDV) were studied. The first clinical signs of infected dogs were high fever, loss of appetite or not eating, vomiting or coughing, sketchy notes in abdominal skin, diarrhea and neurologic signs - walking in a circle. The gross changes were mainly found in lung and intestine including congestion and hemorrhage in lung and intestine, congestion in brain. The other gross changes were enlarged spleen, lymph nodes, swollen gall bladder, and degenerated liver. The microscopic findings were mainly in lung, intestine and brain. There were lots of red blood cells in alveoli, inflammatory brain cells, alveoli and damaged villi of intestine. In the present research, the distribution of CDV in different organs of dogs was identified by using immunofluorescent test.