7. D/C Non GIT Nematodes Flashcards
What is the ecology/epidemology of heartworm?
Domestic and wild canids are normal DH
mosquito vectors
seasonal transmission - during mosquito season
Endemic only in certain areas of Canada. Has not found locally acquired case in AB or SK. Has found in Okanagan Valley of BC, southern MB, ON, QB and parts of NB
Low prevalence in Canada (0.32% in 2019)
dx - antigen testing of blood, modified knott’s test, rads
How long is the PPP of dirofilaria immitis? How long do the adults and L1 live?
PPP: 6-7 mo
Adults live 5-7yrs
L1 2yrs
What is the pathogenesis and clinical signs of heartworm?
often asymptomatic
dec exercise tolerance, coughing, anorexia, weight loss
Severe cases: R heart failure, hepatic congestion, ascites, syncope, death
Caval syndrome (sm dogs, rarely cats): worms block caudal vena cava/tricuspid valve: req immediate surgical removal of worms
How do we diagnose heartworm?
hx, clinical signs
rads/ultrasound - enlarged pulmonary arteries and R heart, may see worms
Dx tests - microfilarial conc test (modified notts), immunodiagnosis (adult female antigen detection in dogs, antibody detection in cats)
How do we prevent heartworm?
preventative medications are recommended for those dogs in and/or travelling to endemic areas n NA
These drugs work by killing circulating L3 and early L4 larvae in recently infected dogs
Preventative meds given to dogs one mo after mosquito season starts until 1 mo after it ends - given 1x/mo, numerous products that all work well
resistance reported in highly endemic regions
recommended to test prior to starting preventatives
What are some monthly heartworm preventatives on the market, what do they kill?
kills L3 and L4
Ivermectin, milbemycin, selamectin, moxidectin
What are some adulticide heartworm preventatives on the market?
Melarsomine (immiticide)
What are some microfilaricides and what do they kill?
Kill L1
Ivermectin, moxidectin
What are some heartworm testing recommendations?
Who? Pets living in/travel to endemic regions
What tests? (antigen, knotts, or Ab for cats)
WHERE? Anually in endemic regions
WHEN? at least 6 mo after last possible exposure (spring in CAD)
WHY TEST? prior to starting preventatives for anaphylaxis, if suspect non-compliance in endemic region, monitor success of treatment, many drug companies will not cover cost of adulticidal tx if pets are not tested annually
What is the life cycle of lung parenchyma?
Adults live in cats, L1 in feces
L1>L3 in IH of snail/slug > either ingested by cat OR by PH > PH w/ L3 eaten by cat
What is the life cycle of dog lunworms - filaroides (oslerus) olseri (airways)
adults live in lungs and L1 pace in feces(can have internal autoinfection)
L1 also shed in saliva + vomit, may be transmitted to pups via regurgitation feeding
Atypical life cycle, direct
ovoviviparous, L1 is shed and infective stage
