subject: Symptoms Of Heartworm Disease In Dogs [print this page] Domestic cats and ferrets are not immune to heartworm disease but dogs seem to be the perfect host. Over 30 species can be affected by the parasite. Coyotes, wolves, foxes, sea lions and other wildlife are known to be susceptible to heartworm disease and even humans can be at risk.
Heartworm larvae is carried by mosquitoes and transmitted to the animal with the bite of the insect. The larvae takes months to mature into male and female worms (in dogs, this takes about seven months) capable of reproducing. Adult affect the organs, migrating to the lungs and heart. They mate and produce microfilariae that is released into the dog's arteries.
Mosquitoes act as an incubator for the tiny new microfilariae to become larvae and without this host insect, the heartworm cannot survive. When the mosquito Preventive heartworm medicine such as Heartgard provides a monthly pet med that will prevent growth of the tiny micro organisms.
One dog can be infected with heartworm larvae several times by different mosquitoes as they feast on the dog's blood and deposit the larvae as they feed. The number of adult worms present in the animal determined the severity of the disease. In a good sized dog (50 lbs) the worms will remain in the pulmonary arteries of the lower lungs until the number of worms exceeds about 50. Then the worms move to the right chamber of the dog's heart and cause an inflammation in the arteries. Without treatment, congestive heart failure is possible due to the weakened condition of the heart.
Very active dogs are more likely to develop severe heartworm disease than are sedentary canines. Worm migration and development thrives when blood flow increases which is what happens as active dogs run and play. Most infections appear between 3-8 years of age but younger dogs are not immune.
Heartworm disease is found in dogs through the U.S. though once it was rare. The Southeastern states account for 45% of heartworm problems where hot, humid climates provide large breeding grounds for mosquitoes. The highest numbers of heartworm disease in dogs ae in states along the Mississippi River and within 150 miles of the Atlantic and Gulf coasts.
Most dogs have few signs of heartworm disease and dogs with low numbers of the worms present in their body may show no symptoms at all until a period of high exercise activity. A cough is often the first symptom of a mild case of heartworm disease. The cough may be joined by a reluctance to participate in high energy exercise and your vet may detect abnormal sounds in the dog's lungs.
Severity of the cough increases and intolerance for exercise are joined tih breathing problems as the disease advances. A short loss of consciousness may result from exercise while fluid retention may make the abdomen appear distended or bloated. Heart sounds may sound abnormal to your vet and an enlarged liver may be found when the dog in a health checkup. Heart failure resulting in sudden death is possible for dogs left untreated.
Veterinarians use the standard in house antigen test for heartworm as a part of heath exams. However, the antigen test does not record the present of worms that are younger than 7 months. Thus a negative test is not an indicator of a dog free of heartworm disease as false negatives do happen. If the test is positive, this is indicated by a blue line appearing on the test strip. The hue of the line (light to dark) indicates the severity of heartworm disease present in the dog.
