Heartworm disease (HWD) is caused by an infection of the filarial (threadlike) worm, Dirofilaria immitis. The dog is the primary host for this large parasite; however, other species – including cats and ferrets – also can be affected. Mature heartworms live predominately within the pulmonary arteries of the dog (the arteries of the lungs). In fact, the name "heartworm" is a bit misleading. Only in heavy or advanced infections do the worms actually reside in the heart.
Nonetheless, the heartworm causes intense reaction of the pulmonary blood vessels. There is also injury to the lungs that can lead to shortness of breath and coughing. The lung injury places a strain on the heart leading to exercise intolerance and eventually heart failure. Advanced cases of HWD cause severe symptoms and can be fatal.
Canine HWD is common throughout many parts of the world. The infection is spread through numerous species of mosquitoes; indeed, this insect is essential to the life cycle of the heartworm. For this reason, HWD is most common where climatic conditions of warmth and moisture are ideal for mosquito development. The heartworm life cycle is complicated and typically involves these stages: 1) mature heartworms living within a host dog produce thousands of microscopic offspring – microfilaria – that circulate in the blood; 2) a mosquito bites a dog (or wild canine) that is infected with mature heartworms; 3) the mosquito ingests microfilaria during the blood meal; 4) the microfilaria enter the mosquito and develop into infective larvae; 5) the mosquito bites another dog and transfers the infective larvae into a new canine host; 6) the larvae develop and migrate into the arteries of the lungs where they mature. The entire life cycle takes about 185 days!
Where mosquitoes are active year round, HWD is spread throughout the year. This is characteristic of subtropical climates, including Florida and the Gulf coast states in the USA. Heartworm infection is also very common in geographic locations that experience four seasons. While the infection cannot be spread during the cold winter, dogs in temperate climates are at high risk for infection between the late spring and mid-autumn mosquito season.
What determines your dog's risk to heartworm infection? Clearly mosquitoes are required to spread this disease, and local mosquito activity is a prime risk factor for your pet. Male dogs and dogs spending a great deal of time out-of-doors are at greater statistical risk. However, the most important predisposing factor for heartworm infection is the failure of a dog to receive appropriate heartworm prevention on a regular basis. Fortunately, the pet owner can control this risk factor with INTERCEPTOR (milbemycin oxime) Flavor Tabs from Novartis Animal Health.
INTERCEPTOR (milbemycin oxime) Flavor Tabs prevent deadly heartworm disease, while they protect your dog against roundworms, hookworms (A. caninum) and whipworms. And INTERCEPTOR Flavor Tabs are approved for puppies
as young as four weeks, weighing two pounds or more. INTERCEPTOR Flavor Tabs are clean, safe, and effective. Safe
INTERCEPTOR has been tested to satisfy FDA requirements (NADA #141-915, Approved by the FDA). It has been used around the globe for over 10 years. Millions of dog owners and their veterinarians trust INTERCEPTOR.
As with other heartworm preventives, dogs must be tested for heartworm prior to using INTERCEPTOR Flavor Tabs. In a small percentage of treated dogs, digestive and neurological side effects may occur. Effective
INTERCEPTOR® (milbemycin oxime) Flavor Tabs® are 100% effective in preventing heartworm disease, and over 97% effective against roundworms, hookworms (A. caninum) and whipworms. Where other products leave your pet vulnerable, INTERCEPTOR provides proven, effective protection against the labeled parasites.