Before treatment, patients should be stabilized to maximize lung function and improve their ability to handle dying worms. Anti-inflammatory doses of prednisone 7 to 14 days before treatment should be given to patients with significant pulmonary infiltrate or respiratory signs (eg, coughing, tachypnea); right-sided heart failure should be treated and stabilized.
Exercise increases blood flow to damaged, blocked vessels and leads to worsening lung injury, increased pulmonary vascular resistance, pulmonary hypertension, and, potentially, right-sided heart failure. Therefore, strict exercise restriction is essential to minimize the severity of cardiopulmonary damage.3,4 Restriction should begin the day of diagnosis and extend throughout the entire treatment and recovery period, with the most extreme restriction lasting 4 to 6 weeks after each melarsomine injection.2 Restriction may vary depending on patient and owner needs but ideally involves cage confinement or restriction to a single room with just short leash walks to eliminate, particularly for more severe cases.
A split 3-dosage protocol can reduce the severity of complications from dying worms.5 The first injection kills approximately 50% of worms, then the lungs are able to recover for one month before the other half of the worms are killed. If the lungs have not fully healed at this point, the second and third injections can be delayed until signs have resolved.6