Table 1 Heartworm treatment schedule

Day 0: Initial evaluation appointment

• Confirmation heartworm test

• Doxycycline 10 mg/kg BID × 30 days, monthly macrocyclic lactone heartworm preventive

• Trazodone 5–10 mg/kg PO dispensed to administer prior to each melarsomine injection^a

Day 60: First melarsomine injection appointment

• Blood chemistry panel^a

• Melarsomine 2.5 mg/kg IM

• Prednisone 0.5 mg/kg BID × 7 days, once daily (SID) × 7 days, then every 48 h × 14 days

• Tramadol 5 mg/kg PO BID × 3 days^a

• Continue monthly macrocyclic lactone heartworm preventive

• Exercise restriction for 30 days^a

Day 90: Second melarsomine injection appointment

• Melarsomine 2.5 mg/kg IM

• Prednisone 0.5 mg/kg BID × 7 days, SID × 7 days, then every 48 h × 14 days

• Tramadol 5 mg/kg PO BID × 3 days^a

• Continue monthly macrocyclic lactone heartworm preventive

• Exercise restriction for 30 days^a

Day 91: Third melarsomine injection appointment

• Melarsomine 2.5 mg/kg IM

Day 120: Post-injection microfilaria test appointment

• Direct blood smear to evaluate for presence of microfilariae

Day 365: Post-injection antigen test appointment

• WITNESS test and screen for microfilariae