Post on 27-Dec-2015
Background
Common name: Heartworm
Definitive host: Canids
Foxes, wolves, dogs, etc. Cats (less persistent) Other mammals
Accidental host: Humans
Transmission Mosquito bite
Geographic Distribution World wide More common in warm
climates (mosquitoes)
Characteristics
Adults Very long and thin Thin alae 3 caudal papillae Can live 5-10 Viviparous
Gives live birth
Males 12-19cm long Spiral or coiled tail
Females 23-30cm long Vagina just posterior
to esophagus
Juveniles (microfilariae) 200-300um Long, pointed tails
Life Cycle Breakdown
3rd stage filarial larvae enter body when mosquito bites travels through blood stream molts once to 4th stage larvae (L4) molts again to adult adults reside in pulmonary arteries female worms produce microfilariae which reside in peripheral blood mosquito bites and picks up microfilariae with blood-meal migrate from mid-gut to Malpighian tubules (in abdomen) microfilariae develpe to 1st stage larvae, then to L2 and L3 L3 migrate to proboscis (mosquito pokey thing) mosquito bites and deposit L3 to host
**microfilariae can be cross placental barrier to puppies but adult worms will not form, no intermediate host interaction**
Human Pathway
**follows same pathway in humans**
Adults end up in smaller blood vessels in lungs
build up causing “coin-lesions”
Symptoms
Dogs / Cats Pulmonary artery blockage
Coughing Difficulty breathing Coughing up blood Exhaustion Fainting Weight loss
Heavy infection ~ 25 worms Further infection can fill cavities
of heart
Symptoms
Humans Most are asymptomatic Cough coughing up blood fever chest pain Pulmonary dirofilariasis
Dying worms produce granulomasin pulmonary arteries
Pleural effusion Excess fluid between tissue lining lungs and chest cavity
Inflamation caused by dying adult worms Coin lesions in pulmonary arteries
Diagnosis
Blood tests Observe microfiliariae in blood
Parasitic antigen testin
Identification of coin lesions in lungs and pulmonary arteries Lesions observed in chest Xray Mostly found by accident since most are asymptomatic
Identification of nodules under skin
Examination of inflamed tissue
Treatment
Dogs / Cats Immiticide® (Adulticide) Anti-inflamatory drugs Surgical removal (if necessary)
Humans Surgical removal of lung granulomas and inflamed
nodules under skin
Drugs aren’t usually needed
Prevention
Dogs / Cats Anti heartworm medications Flee, tick, and mosquito medications
Humans Vector control Bug spray
Work Cited
http://www.cdc.gov/parasites/dirofilariasis/faqs.html
http://www.bronchitissymptomsinadults.org/http://www.heartwormsociety.org/UrgentAlert
-8-9-11.pdfhttp://vetpda.ucdavis.edu/parasitolog/Parasite
.cfm?ID=50http://www.cvbd.org/en/mosquito-borne-disea
ses/heartworm-disease/pathogen/http://www.heartwormsociety.org/pet-owner-
resources/heartworm.html#signs