Background Information

Dirofilaria immitis, the heartworm or dog heartworm, is a parasitic roundworm that is spread from host to host through the bites of mosquitoes. The heartworm is a type of filarial worm, a small thread-like worm that causes filariasis. The parasite is commonly called "heartworm"; however, adults often reside in the pulmonary arterial system (lung arteries), as well as the heart, and a major effect on the health for the animal is a manifestation of damage to the lung vessels and tissues. Heartworm infection may result in serious disease for the host, with death typically as the result of congestive heart failure. LiliF CHW Ag RAPID KIT is a Lateral Flow Immuno-Chromatographic Assay kit for the rapid and accurate qualitative detection of Dirofilaria immitis antigen in canine whole blood, serum or plasma.

Adult heartworms grow several inches in length and reside in the pulmonary arteries where it can obtain enough nutrients. The heartworms inside the arteries trigger inflammation and form hematoma. The heart, then, should pump more often than before as the heartworms increase in number, blocking the arteries.

 When infection deteriorates (over 25 heartworms exist in a 18 kg dog), the heartworms move into the right atrium, blocking the flow of blood.

 When the number of heartworms reaches more than 50, they could occupy atriums and ventricles. 

 When infected with over 100 heartworms in the right part of the heart, the dog loses the function of the heart and eventually dies. This fatal phenomenon is called as “Caval Syndrom.”  

Unlike other parasites, the heartworms lay small insects called as microfilaria. Microfilaria in mosquito moves into a dog when the mosquito sucks blood from the dog. The heartworms that can survive in the host for 2 years die if they do not move into another host within that period. The parasites residing in a pregnant dog can infect its embryo.

 Early examination of heartworms is very important in eliminating them. Heartworms go through several steps such as L1, L2, L3 including the transmission stage through mosquito to become adult heartworms.