New York: A rare, severe form of human lung disease has now been discovered in dogs, says a study that could be important for human medicine because the canine disease may serve as a model for further research. "Our research is the first to document the existence of pulmonary veno-occlusive disease, or PVOD, in dogs," said Kurt Williams, lead author of the study and an expert in respiratory pathology at the College of Veterinary Medicine, Michigan State University. The study was published in the journal Veterinary Pathology. "PVOD is considered one of the most severe forms of pulmonary hypertension," Williams noted. Pulmonary hypertension develops because of abnormal blood vessels in the lungs, which makes it harder for the heart to push blood through and provide oxygen to the rest of the body. In cases of PVOD, the small veins in the lungs become blocked, increasing pressure in these blood vessels, and ultimately causing heart failure. "The same process happens in canines," Williams said. "These dogs also come in with similar symptoms as humans, yet because subtle changes in health may not be recognised as quickly in dogs, death can occur quickly once the animal is seen by a veterinarian," Williams noted. Symptoms include cough, increased rate of breathing, respiratory distress, loss of appetite and chronic fatigue. Fatal progression of the disease in humans can last up to two years. There are very few effective treatment options for PVOD and a lung transplant often becomes the best choice, according to the researchers. Williams said that the discovery could be important for human medicine because the canine disease may serve as a model for human PVOD. "PVOD might be more common in dogs than in people, but this has yet to be determined and needs to be looked at further," Williams said.