Canine Heartworm Flashcards
Which definitive host of heartworm develops high microfilaria counts and serve as a reservoir for infection?
Domestic and wild canines
Which hosts of heartworm have low microfilaria counts, transient microfilaremia, and are less likely to transmit?
Cats and ferrets
Who is the intermediate host of heartworm?
Female mosquito
At 80 degrees 80% humidity, heartworm larva within the mosquito develop to the infective stage in ________
10-14 days (L3 stage)
How many days does it take for L3 to molt to L4?
3-12 days
How many days does it take for heartworm to finally molt to immature adults?
50- 70 days
How long does it take for adult heartworm to reach pulmonary vasculature?
67-120 days
Final location of heartworm based on worm burden
<5 pulmonary artery
5-40 right ventricle
>40 right atria, ventricle, vena cava
How long does it take heartworm to reach sexual maturity?
120 days post infection
What is the eventual adult size of heartworm?
Female 8-12 in
Male 4-6 in
when can circulating microfilaria be found in a dog?
6-9 months post infection
What do we use for heartworm prevention?
Macrocyclic lactones (ivermectin, selamectin, moxidectin, milbemycin)
What is heartworm preventive effective against?
Microfilaria, L3 & L4 stages
When should puppies start HW preventative?
No later than 8 weeks old
How often and what do we use to test for heartworm?
Antigen and microfilaria yearly for all dogs every 7 months
