Caval syndrome is a condition from heavy heartworm infestations, causing intracardiac obstruction,
potentiating in multiple fatal complications, and poor prognosis. Early diagnosis is imperative for prompt
treatment and echocardiography has the benefit of aiding in exploring the cardiac structure and the worm
burden. According to The American Heartworm Society guideline (2020), it has established several treatment
regimens both medical and surgical. The purpose of this case report is to determine the clinical efficacy of
long-term macrocyclic lactone in the treatment of heartworm in a dog with caval syndrome. An 8-year-old
female French bulldog was presented with ascites. Numerous heartworms were detected intracardiac from an
echocardiography. A monthly application of 10% imidacloprid and 2.5% moxidectin with 4 weeks of 10 mg/kg
doxycycline had shown the efficacy in controlling heartworms of a dog with caval syndrome thus far, along with
an exercise restriction to prevent complication from pulmonary thromboembolism. Reassessment of this patient
was planned for a monthly health screening and a 3-month echocardiography for worms migration, thrombi, and
antigen testing. After 3 months, the worms were unable to detect from echocardiography and the dog was no
longer required abdominocentesis. The dog is currently living well and planned on giving a regular heartworm
prevention program after 12 months.
Keywords
caval syndrome, canine heartworm, long term macrocyclic lactone