Chylothorax is an accumulation of fluid containing triglycerides in the chest. This rare but complex disorder may have any of a number of causes: malignancy, fungal infections, heartworm disease, heart disease and birth defects of the lymphatic system. Trauma may also be involved. Many cases never have an actual diagnosis; these are called idiopathic chylothorax.

A number of highly sophisticated therapies exist. Surgical tying of the thoracic duct bring chyle, the fluid involved, through the thorax. Surgical placement of various types of drainage mechanisms or shunts have been used as well, such as a pleuroperitoneal shunt. According to the literature, surgical ligation of the thoracic duct in idiopathic cases has the highest rate of success, but treatment failures are common.

Frequent aspiration of the chylous exudate from the chest by syringe or pump is the most common approach in private practice. The current adjunctive therapy is to use rutin, a metapyrone compound available in health food stores. It is being tried in humans with chronic edema (fluid accumulation) in their limbs. It is supposed to increase the action of macrophages (cells that engulf material) and allow absorption of edema fluid. Alice M. Wolf, DVM, one of the best veterinary specialists in the country, is trying 250 milligrams of rutin three times daily since no established dose exists.