When you see your dog running in the sun, you may not realize that a parasite called "heartworm" is silently threatening its life. This disease, spread by mosquitoes, has subtle early symptoms, but once it progresses to late stages, treatment becomes difficult and it can be fatal. Let’s take a closer look at this "silent killer" and learn how to protect our furry friends.      

Pathogen Overview

        Heartworm is a type of filarial nematode transmitted by mosquitoes. Adult worms can grow up to 10-30 cm long and cause severe, potentially fatal disease. Heartworms live in the heart, lungs, and blood vessels of infected mammals, damaging these organs and leading to serious complications. Dogs are the primary hosts, but other species, including wild canids, ferrets, cats, and even humans, can be infected.

Life Cycle of Heartworm

        Adult female heartworms produce microfilariae in the host’s body. When a mosquito bites an infected animal, it picks up these microfilariae. Within 10 to 14 days, the microfilariae develop into infective larvae (L3). During blood feeding, mosquitoes transmit these larvae to new hosts. Inside the host, the larvae mature through several stages, eventually becoming adult worms in 6-7 months, where they can live for 5-7 years, causing ongoing damage.

Clinical Symptoms

        Heartworm disease is a chronic, progressive condition. In early stages, dogs may show no symptoms, but as the infection progresses, they can develop chronic lung disease and congestive heart failure. Symptoms may include coughing, exercise intolerance, weight loss, lethargy, and difficulty breathing. In severe cases, symptoms like labored breathing, heart murmur, fainting, liver enlargement, and kidney failure may occur.

Prevention and Detection

        Prevention is crucial, as treatment for heartworm infection is risky and lengthy. In the U.S., the American Heartworm Society (AHS) and the Companion Animal Parasite Council (CAPC) recommend annual antigen and microfilariae testing for dogs over 7 months old. Antigen tests detect specific proteins secreted by female heartworms, but may produce false negatives if the infection is early or the parasite load is low. Microfilariae testing checks for the presence of larvae in the dog’s blood and is reliable after about 6 months of infection.

Treatment

        Treatment for heartworm disease is complex and high-risk, involving multiple stages of medication to kill adult worms and strict exercise restrictions to prevent severe complications like pulmonary embolism. Antibiotics, anti-inflammatory drugs, and anticoagulants are also used during the treatment, which may take several months. Even with successful treatment, the heart and lung damage is often permanent.

        Regular preventive medication is the best strategy to protect your dog, avoiding the need for expensive and high-risk treatments. Even if your dog has been on preventive medicine, annual heartworm testing is recommended.

        As an expert in animal diagnostics,Yaoshuoling Technology Co., Ltd has developed an antigen detection kit for heartworm, offering quick, easy, and accurate testing to help veterinarians and pet owners identify infection risks early. For more information or to get testing solutions, please contact us through the "Contact Us" section on our website. Our professional team is here to assist you.