Rare human lung disease discovered in dogs

PVOD is diagnosed in only about 10% of pulmonary hypertension cases where no other cause of the disease has been determined, researchers said

A rare, severe form of pulmonary hypertension, which up until now was only classified as a human lung disease, has been discovered in dogs, an advance that may help develop medicines to treat the condition.

“Our research is the first to document the existence of pulmonary veno-occlusive disease, or PVOD, in dogs. PVOD is considered one of the most severe forms of pulmonary hypertension,” said Kurt Williams, from the Michigan State University.

PVOD is diagnosed in only about 10 per cent of pulmonary hypertension (PH) cases where no other cause of the disease has been determined, researchers said. Unfortunately, there are very few effective treatment options for PVOD and a lung transplant often becomes the best choice.

“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.

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.”

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. “PVOD is a poorly understood disease not just because it’s so rare, but also because there have been no other animals known to have the disease,” Williams said.

Williams said the discovery could be important for human medicine because the canine disease may serve as a model for human PVOD.

The study was published in the journal Veterinary Pathology.