Scientific name of the heartworm.
How long can L1 remain in the bloodstream?
Up to 2 years
How long does it take for the L1 to develop into the infective L3 stage once ingested by the intermediate host?
10-14 days/ 2-3 weeks
What is the temp requirement for L1-L3 in the mosquito?
What is the lifespan of adult heartworms?
How long does it take for the L3-L4 molt?
How long does it take for the L4-L5 molt?
How long does it take for the L5 to mature to adult once they migrate to the pulmonary arteries and right heart?
What is the prepatent period for heartworms?
What are the 4 diagnostic lab tests for microfilaria?
- Modified Knott's
- Filter (ex Difil)
- Buffy Coat
- Direct Smear
What are some ways of diagnosing heartworms other than testing for microfiliaria or anitgen/antibody tests?
- Radiograph: enlarged pulmonary arteries and right heart
- CBC: increased basophils/eosinophils
What is occult heartworm disease?
Presence of adults without microfilaria
What are the five possible reasons for occult heartrworm disease?
- Immature adults
- Adults one sex or sterile
- Ectopic adults
- Immune mediated clearence
- Montly prevetative: kill microfilaria
What are two considerations before starting TX of heartworms?
- Cost: can the client afford tx?
- Overall health of animal: liver, kidney function, able to withstand tx.
What tx is older and less effective (63%)?
thiacetarsamide (Caparsolate)- given IV, bid, 2-3 days
What tx is newly approved and more effective (90.8%)?
melarsomine dihydrochloride (Immiticide)- deep IM sid/bid, 2 days
What two products are used off label as microfilaricidals?
- Milbemycin oxime
Ivermectin + Pyrantel pamoate (Heartgard 30 plus, Iverheart, TriHeart Plus)
HW prevention, rounds, hooks
Milbemycin oxime (Interceptor)
HW prevention, rounds, hooks, whips
monthly topical; HW prevention, rounds, hooks in CATS ONLY, fleas, some mites, some ticks.
Lifespan of adults in cats
2 years (vs 5 years in dogs)
Prepatent period in cats
8 months (vs 6 months in dogs)
Moxidectin (Proheart 6)
SUBQ injection, every 6mo. HW preventative, hookworms @ time of admin.
What are some HW preventatives in cats?
- Ivermectin (Heartgard 30 for cats)
- Selamectin (Revolution)- also rounds, hooks in cats
- Advantage Multi
What is meant by "caval syndrome?"
Adults in the right heart and vena cava.
What are some clincal signs of heartworm disease?
- Exercise intolerance
- Chronic cough
- Remittent ascities