Parasitology Lecture Midterm Flashcards
____________ may cause fatal pneumonia in puppies if mom was infected
Roundworm/Toxocara
why would we use a tapeworm crush?
to examine eggs within the segment of a tapeworm that does not otherwise expel its eggs
what are 3 possible paratenic hosts of Toxocara?
rodents, rabbits and earthworms
Are hookworms zoonotic?
Yes; via cutaneous larval migration
are hookworms bloodfeeders?
yes
what two factors decide the clinical signs of Toxocara infection?
number of worms & age of host
The prepatent period of Dioctophyma is _______ months
3-6
why is Toxocara a public health concern?
because our common household disinfectants do not kill toxocara eggs
What is the life cycle of Strongyloides?
L3 is infective and ingested or penetrates the skin - migrates through blood - lungs and trachea, coughed up and swallowed - adult female resides in small intestine - deposit eggs and L1 is passed in feces
What paratenic host does Pearsonema plica use?
earthworm
what are cestodes?
flatworms that are ribbon-like and segmented into Proglottids behind a Scolex
How big do Heartworms get?
up to 30 cm
how is Toxascaris transmitted?
ingestion of egg
why is single sex infection of Toxocara a concern?
infertile worms make diagnosis by fecal float impossible
What are some clinical signs of Whipworm infection?
Sometimes one, damage of tissue as blood vessels in severe cases. Can also show severe diarrhea, dehydration, emaciation and death
What is an intermediate or secondary host?
host in which a parasite passed through as larva or during asexual phases of development
What is a suitable treatment for Strongyloides?
Ibermectin
what is the prepatent period of Whipworms?
3 months
Can humans get a Toxocara infection(
Yes; usually children
How is Capillaria hepatica ingested?
fecal contaminant or ingestion of infected animal with an infected liver
what is a characteristic sign of Toxocara in puppies?
pot belly
True or false; areas with less bodies of water will have significantly lower cases of Heartworm
true because mosquitoes need water to reproduce and therefore transmit heartworm
How long are whipworm adults?
45-75mm
How is Pearsonema plica transmitted?
infected urine or ingestion of paratenic host
The ________ is the best criteria for distinguishing between microfilariae
shape of head
True or false; Dirofilaria can cause cirrhosis in canines
true
What Paratenic hosts does Dioctophyma use?
fish and frogs
Define larva
immature stage in the life cycle of a parasite; usually between egg and adult
What are clinical signs of Dirofilaria in Canine?
cirrhosis, pneumonitis, thrombosis, caval syndrome
True or false; Whipworms can only live in the environment for a few weeks
False. It can live for years.
Describe the life cycle of Dirofilaria immitis
Adults in pulmonary artery - produce microfilaria (L1) to be passed in blood - carried in blood up to 2 years - picked up by mosquito during blood meal - L3 deposited onto skin in mosquitos saliva during next blood meal - larva enter through bite wound - migrates to thorax L4 - become immature adults (L5) and finish in pulmonary artery, vena cava or right atrium
What size do Adult Heartworm get to be?
15-31 cm
Dioctophyma uses ______ as an intermediate host
aquatic invertebrates
How long can the Microfilaria stage of Heartworm live in the blood?
2 years
What is a Trematode?
flatworms with unsegmented, leaf-like bodies
what is a characteristic feature of the adult Whipworm?
whip shaped body
Liver failure is a direct result of ________ from Heartworm infection
caval syndrome
what are two alternative names for a Primary Host?
Definitive host or final host
why is Toxascaris of more concern than Toxocara?
it is harder to treat
What is the lifecycle of Aleurostrongylus abstrusus?
adults found in bronchioles & alveolar ducts - eggs are laid, develop to larvae, coughed up, swallowed and passed in feces
Which parasite is associated with “Puppy Breathe”?
Toxocara/Roundworm
What size do Dirofilaria microfilaria get to be?
286-340um
What is peculiar about the Strongyloides life cycle?
Once the adult females are in the small intestine, they reproduce parthogenically via mitosis and deposit eggs
Hookworms can enter the body through skin penetration. Describe this life cycle.
Dog walks on L3 - larva penetrates foot pads - enters lymphatic system - migrated to heart and through the pulmonary artery moves to the lungs - is coughed up, swallowed and resides in small intestine