Do I really need to be concerned?

Most definitely! Exposure to Canine Heartworms is widespread, and countless numbers are infected annually. The condition often progresses to death.

Prevalence of Canine Heartworm Infection

Heartworm infection has been found in dogs in all 50 states, and is considered at least regionally endemic in each of the states except Alaska. Any dog regardless of age, sex, or habitat is susceptible to heartworm infection.

How is it contracted and spread?

The disease is spread from host to host by mosquitoes carrying heartworm larvae. The infective larvae usually come from dogs within the population that have canine heartworm disease (dirofilaria immitis).

How dangerous is it?

The adult worms disrupt the normal blood flow through the heart and vessels of the lungs, causing signs similar to congestive heart disease. All cases are debilitating, and many will result in death if untreated.

Circulating microfilaria block small capillaries and cause damage at the microscopic level to major organs like the kidneys, liver and lungs.

Treatment usually reverses the damage, though in severe cases recuperative time is long.

Is Canine Heartworm Disease preventable?

Yes, prevention is easy with one of the following methods:

• Oral preventatives
• Oral preventatives are designed to be used monthly. Be sure to use products formulated specifically for dogs. Appropriate products include Heartgard, Interceptor, and Iverheart.
• Topical products
• Apply to the skin according to directions to prevent heartworm disease, as well as to control other internal and external parasites. Once again, use only products intended for and approved. One such topical product is Revolution.

Your veterinarian is the best informed source of which form of prevention is better suited to your individual pet.

How is canine heartworm infection diagnosed?

• Clinical signs are often nonspecific and include:
• Coughing
• Breathing difficulty (dyspnea)
• Sluggishness
• Exercise intolerance
• Loss of weight or condition
• There are diagnostic tests which are usually capable of pinpointing canine heartworm infection. Diagnostic aids include:
• Blood tests for occult heartworm antigen
• Blood tests for circulating microfilaria
• Chest x-rays
• Clinical signs
• Canine heartworm disease resembles other cardiovascular diseases and can be misdiagnosed.

1. Microscopic immature heartworms are transmitted to your dog through the bite of infected mosquitos.
2. These infective larvae migrate through tissues and eventually reach the heart, where they mature to adult heartworms.
3. The mature worms produce more immature microfilaria, which circulate in the bloodstream. Then:
1. Other mosquitos pick up the microfilaria when they bite, and transmit them to other dogs.