Heartworm Disease Flashcards
How is heartworm disease transmitted?
Transmitted by many mosquito species.
What is the cause of heartworm disease?
Dirofilaria immitis- a nematode.
What are the wildlife reservoirs of heartworm disease?
- Foxes.
- Racoons.
- Seals.
- Sea lions.
- Wolves.
- Coyotes.
What are the domestic reservoirs of heartworm disease?
- Ferrets.
- Cats.
- Dogs.
What climates has heartworm disease been reported in?
- Temperate.
- Semi-tropical.
- Tropical.
*Has been reported in all 50 U.S. States.
What is the first step of the heartworm lifecycle?
Mosquitos ingest microfilaria.
What is the second step of the heartworm lifecycle?
The microfilaria molt into the L1 stage, then the L2 stage, and finally the L3 stage in the mosquito. Takes 2 weeks.
What is the third step of the heartworm lifecycle?
The mosquito bites a mammal and the L3 larvae enters the tissues of the host.
What is the fourth step of the heartworm lifecycle?
The L3 larvae mature to L4 larvae in the tissue of the host. 3-12 days post-infection.
What is the fifth step of the heartworm lifecycle?
The L4 larvae develop into immature adults. 50-70 days post-infection.
What is the sixth step of the heartworm lifecycle?
The immature adults migrate to the heart (specifically the pulmonary artery and right ventricle) and develop into sexually mature adults. 70-120 days post-infection.
What is the seventh step of the heartworm lifecycle?
The mature adults produce microfilaria. Happens 6-months post-infection.
How long are adult heartworms?
15 cm.
What does the presence of adults in the pulmonary vasculature cause?
- Direct mechanical trauma.
- Immune system stimulation.
- Inflammation (thickening of the vessel walls).
What do the symptoms of heartworm disease result in?
- Inflammation in the lungs.
- Pulmonary hypertension.
- R. side heart failure.